EVALUATION KIT AVAILABLE MAX77818 Dual Input, Power Path, 3A Switching Mode Charger with FG General Description Benefits and Features The MAX77818 is a high-performance companion PMIC for the latest smartphones and tablet computers. The PMIC includes a dual input, smart power path 3.0A switch mode charger with reverse boost capability and adapter input protection up to 16VDC withstand, proprietary ModelGaugeTM (mg5) fuel gauge technology. The switch mode battery charger's operating frequency is 4MHz and includes integrated, low-loss switches to provide the industry's smallest L/C size, lowest heat, and fastest battery charging programmable up to 3.0A. The charger has two inputs that accept adapter/USB (CHIN) and/or wireless type inputs (WCIN). The wireless input can simultaneously charge the battery while powering USB-OTG type accessories. The USB-OTG output provides true-load disconnect and is protected by an adjustable output current limit. The battery charger includes smart power path and I2C adjustable settings to accommodate a wide range of battery sizes and system loads. When external power is applied from either input, battery charging is enabled. With a valid input power source (adapter or wireless charger), the BYP pin voltage is equal to the input voltage minus resistive voltage drop. During battery-only reverse boost operation, the BYP output can be regulated with the reverse boost feature and provides up to 5V at 1.5A and requires no additional inductor, allowing the MAX77818 to power USB OTG accessories. The switching charger is designed with a special CC, CV, and die temperature regulation algorithm. ModelGauge (mg5) provides accurate battery fuel gauging without calibration and operates with extremely low battery current. Dual Input Switchmode Battery Charger * Adapter/USB Input * Up to 13.4V Adapter Charging * Up to 4.0A rated, Input Current Protection (Programmable) * Wireless Charging Input * Up to 5.9V Wireless Charging * Up to 1.26A, Input Current Protection (Programmable) * Support USB-OTG Accessories * Battery Charge Current, Up to 3.0A * No Sense Resistor * CC, CV, and Die Temperature Control * Integrated Battery True-Disconnect FET * RDS(ON) = 12.8m * Rated Up to 4.5ARMS, Discharge Current Limit (Programmable) * Reverse Boost Capability * Supports USB-OTG Accessories * Up to 5.1V/1.5A * Adjustable OCP ModelGauge (mg5) Battery Fuel Gauge * 1% SOC Accuracy, No Calibration Cycles, Very Low IQ * Time-to-Empty and Time-to-Full Prediction Two Safeout LDOs I2C Serial Interface 72-Bump. 3.867mm x 3.608mm WLP with 0.4mm Pitch The safeout LDO drive system USB interface devices. The MAX77818 features a I2C revision 3.0-compatible serial interface that comprises a bidirectional serial data line (SDA) and a serial clock line (SCL). Applications Smartphones and Tablets Other Handheld Devices ModelGauge is a trademark of Maxim Integrated Products, Inc 19-6902; Rev 0; 10/15 Ordering Information appears at end of data sheet. MAX77818 Dual Input, Power Path, 3A Switching Mode Charger with FG Absolute Maximum Ratings Switching Charger CHGIN to GND.......................................................-0.3V to +16V BYP to GND...........................................................-0.3V to +16V WCIN, PVL, AVL, BAT_SP, BATT, SYS, DETBATB to GND................................................-0.3V to +6V BST to PVL.............................................................-0.3V to +16V BST to CHGLX.........................................................-0.3V to +6V WCINOKB, INOKB to GND............................-0.3V to SYS+0.3V BAT_SN, CHGPG to GND....................................-0.3V to +0.3V CHGLX, CHGPG Continuous Current...........................3.5ARMS SYS, BATT Continuous Current.....................................4.5ARMS CHGIN, BYP Continuous Current..................................4.0ARMS WCIN Continuous Current.............................................1.5ARMS Fuel Gauge VBFG, to GND.......................................................-0.3V to +2.2V THMB, THM to GND.................................. -0.3V to VAVL + 0.3V Safeout LDOs SAFEOUT1, SAFEOUT2 to GND..............................-0.3V to 6V SAFEOUT1, SAFEOUT2 Continuous Current..................100mA I2C and Interface Logic VIO to GND...............................................................-0.3V to +6V SDA, SCL to GND........................................... -0.3V to VIO+0.3V INTB to GND..........................................-0.3V to VSYS_A + 0.3V TEST_, VCCTEST, SYS_ to GND.............................-0.3V to +6V GND_ to GND.......................................................-0.3V to +0.3V Thermal Ratings Operating Temperature Range............................ -40C to +85C Junction Temperature.......................................................+150C Storage Temperature Range............................. -65C to +150C Soldering Temperature (reflow)........................................+260C Continuous Power Dissipation (TA = +70C) (derate 28.9mW/C with 4L board, above 70C)............2.31W CHGLX has internal clamp diodes to CHGPG and BYP. Applications that forward bias these diodes should take care not to exceed the IC's package power dissipation limits. Package Thermal Characteristics (Note 1) WLP Junction-to-Ambient Thermal Resistance (JA)........34.6C/W Note 1: Package thermal resistances were obtained using the method described in JEDEC specification JESD51-7, using a four-layer board. For detailed information on package thermal considerations, refer to www.maximintegrated.com/thermal-tutorial. Stresses beyond those listed under "Absolute Maximum Ratings" may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. Electrical Characteristics General Electrical Characteristics (VSYS = +3.7V, CHGIN = 0V , VIO = 1.8V, TA =-40C to +85C, unless otherwise noted. Limits are 100% production tested at TA = +25C . Limits over the operating temperature range and relevant supply voltage range are guaranteed by design and characterization. Typical values are not guaranteed.) PARAMETER Shutdown Supply Current (BATT) No Load Supply Current (BATT) SYMBOL CONDITIONS MIN All circuits off VBATT = 3.6V Fuel gauge is on All other circuits off, VBATT = 3.6V TYP MAX UNITS 23 50 A 50 100 A 5 V SYS INPUT RANGE SYS Operating Voltage Guaranteed by VSYSUVLO and VSYSOVLO 2.8 SYS Undervoltage Lockout Threshold VSYS falling, 200mV hysteresis 2.45 2.5 2.55 V SYS Overvoltage Lockout Threshold VSYS rising, 200mV hysteresis 5.2 5.36 5.52 V www.maximintegrated.com Maxim Integrated 2 MAX77818 Dual Input, Power Path, 3A Switching Mode Charger with FG Electrical Characteristics (continued) General Electrical Characteristics (VSYS = +3.7V, CHGIN = 0V , VIO = 1.8V, TA =-40C to +85C, unless otherwise noted. Limits are 100% production tested at TA = +25C . Limits over the operating temperature range and relevant supply voltage range are guaranteed by design and characterization. Typical values are not guaranteed.) PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS 0.3 x VIO V LOGIC AND CONTROL INPUT SCL, SDA Input Low Level TA = +25C SCL, SDA Input High Level TA = +25C SCL, SDA Input Hysteresis TA = +25C SCL, SDA Logic Input Current VIO = 3.6V 0.7 x VIO V 0.05 x VIO -10 SCL, SDA Input capacitance V +10 10 A pF SDA Output Low Voltage Sinking 20mA 0.4 V Output Low Voltage INTB ISINK = 1mA 0.4 V 1000 kHz I2C-COMPATIBLE INTERFACE TIMING FOR STANDARD, FAST, AND FAST-MODE PLUS (Note 2) Clock Frequency Hold Time (Repeated) START Condition fSCL tHD;STA 0.26 s CLK Low Period tLOW 0.5 s CLK High Period tHIGH 0.26 s Setup Time Repeated START Condition tSU;STA 0.26 s DATA Hold Time tHD:DAT 0 DATA Valid Time tVD:DAT 0.45 s DATA Valid Acknowledge Time tVD:ACK 0.45 s DATA Setup Time tSU;DAT 50 ns Setup Time for STOP Condition tSU;STO 0.26 s Bus Free Time Between STOP and START tBUF 0.5 s Pulse Width of Spikes that Must Be Suppressed by the Input Filter www.maximintegrated.com (Note 3) s 50 ns Maxim Integrated 3 MAX77818 Dual Input, Power Path, 3A Switching Mode Charger with FG Electrical Characteristics (continued) General Electrical Characteristics (VSYS = +3.7V, CHGIN = 0V , VIO = 1.8V, TA =-40C to +85C, unless otherwise noted. Limits are 100% production tested at TA = +25C . Limits over the operating temperature range and relevant supply voltage range are guaranteed by design and characterization. Typical values are not guaranteed.) PARAMETER SYMBOL CONDITIONS CB = 100pF MIN TYP MAX UNITS I2C-COMPATIBLE INTERFACE TIMING FOR HS MODE (Note 2) Clock Frequency fSCL 3.4 MHz Setup Time Repeated START Condition tSU;STA 160 ns Hold Time (Repeated) START Condition tHD;STA 160 ns CLK Low Period tLOW 160 ns CLK High Period tHIGH 60 ns DATA Setup time tSU;DAT 10 ns DATA Hold Time tHD:DAT 0 ns SCL Rise Time tRCL TA = +25C 10 40 ns Rise Time of SCL Signal After a Repeated START condition and After an Acknowledge Bit tRCL1 TA = +25C 10 80 ns SCL Fall Time tFCL TA = +25C 10 40 ns SDA Rise Time tRDA TA = +25C 10 80 ns SDA Fall Time tFDA TA = +25C 80 ns Setup Time for STOP Condition Pulse Width of Spikes that Must be Suppressed by the Input Filter www.maximintegrated.com tSU;STO 160 ns 10 ns Maxim Integrated 4 MAX77818 Dual Input, Power Path, 3A Switching Mode Charger with FG Switching Charger Electrical Characteristics (VCHGIN = 5V, VBATT = 4.2V, TA = -40C to +85C, unless otherwise noted. Typical values are at TA = 25C. Fast-charge current is set for 1.5A, done current is set for 150mA. Limits are 100% production tested at TA = +25C . Limits over the operating temperature range and relevant supply voltage range are guaranteed by design and characterization. Typical values are not guaranteed.) PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS CHGIN INPUT CHGIN Operating Voltage Range Operating voltage 3.2 VOVLO V WCIN Operating Voltage Range Operating voltage 3.2 VOVLO V 14 V 6 V CHGIN Overvoltage Threshold (Note 4) VCHGIN-OVLO VCHGIN rising 13.4 WCIN Overvoltage Threshold (Note 4) VWCIN-OVLO VWCIN rising 5.9 WCIN Overvoltage Threshold Hysteresis VWCINH-OVLO VWCIN falling 100 mV CHGIN Overvoltage Threshold Hysteresis VCHGINH-OVLO VCHGIN falling 300 mV VWCIN/BUS_DET rising, 100mV overdrive, not production tested 10 us VWCIN/BUS_DET falling, 100mV overdrive, not production tested 20 us WCIN/CHGIN Overvoltage Delay WCIN/CHGIN to GND Minimum Turn-On Threshold Range (Note 4) TD-OVLO VWCIN/CHGIN_ UVLO WCIN/CHGIN to GND Minimum Turn-On Threshold Accuracy VWCIN/CHGIN_ WCIN/CHGIN to SYS Minimum Turn-On Threshold (Note 4) VWCIN/ WCIN/CHGIN Turn-On Threshold Delay WCIN/CHGIN Adaptive Current Regulation Threshold Range (Note 5) UVLO CHGIN2SYS TD-UVLO VWCIN/ VCHGIN rising, 100mV hysteresis, programmable at 4.5V, 4.9V, 5.0V, 5.1V, WCIN input is disabled when valid CHGIN input is detected 4.5 VWCIN/CHGIN rising, 4.5V setting 4.4 VSYS + 0.12 VCHGIN rising, 50mV hysteresis, WCIN input is disabled when valid CHGIN input is detected Not production tested 4.3 4.9V setting 4.8 CHGIN Current-Limit Range Programmable, 500mA default, factory programmable option of 100mA, production tested at 100mA, 500mA, 1000mA, 1800mA, 4000mA settings only WCIN Current-Limit Range Programmable, 500mA default, factory programmable option of 100mA, production tested at 100mA, 250mA, 500mA, 1000mA settings only WCIN/CHGIN Adaptive Voltage Regulation Threshold Accuracy www.maximintegrated.com VWCIN/ CHGIN_REG 5.1 V 4.5 4.6 V VSYS + 0.20 VSYS + 0.28 V 10 Programmable at 4.3V, 4.7V, 4.8V, 4.9V CHGIN_REG 13.7 us 4.9 V 5 V 0.1 4 A 0.06 1.26 A 4.9 Maxim Integrated 5 MAX77818 Dual Input, Power Path, 3A Switching Mode Charger with FG Switching Charger Electrical Characteristics (continued) (VCHGIN = 5V, VBATT = 4.2V, TA = -40C to +85C, unless otherwise noted. Typical values are at TA = 25C. Fast-charge current is set for 1.5A, done current is set for 150mA. Limits are 100% production tested at TA = +25C . Limits over the operating temperature range and relevant supply voltage range are guaranteed by design and characterization. Typical values are not guaranteed.) PARAMETER WCIN or CHGIN Supply Current VWCIN or VCHGIN Input Current Limit VCHGIN Input Current Limit SYMBOL IIN IINLIMIT IINLIMIT CONDITIONS MIN TYP MAX UNITS mA VWCIN/CHGIN = 2.4V, the input is undervoltage and RINSD is the only loading 0.075 VWCIN/CHGIN = 5.0V, charger disabled 0.17 0.5 VWCIN/CHGIN = 5.0V, charger enabled, VSYS = VBATT = 4.5V, (no switching, battery charged) 2.7 4 VWCIN or VCHGIN = 5.0V, charger enabled, VBATT = 3.8V, 100mA input current setting, TA = +25C 90 102 108 VWCIN or VCHGIN = 5.0V, charger enabled, VBATT = 3.8V, 500mA Input current setting, TA = +25C 462.5 487.5 500 VWCIN or VCHGIN = 5.0V, charger enabled, VBATT = 3.8V, 1000mA Input current setting, TA = +25C 950 975 1000 VWCIN or VCHGIN = 5.0V, charger enabled, VBATT = 3.8V, 1000mA input current setting, TA = 0C to +85C 926 975 1024 VCHGIN = 5.0V, charger enabled, VBATT = 3.8V, 1800mA input current setting, TA = +25C 1710 1755 1800 VCHGIN = 5.0V, charger enabled, VBATT = 3.8V, 1800mA input current setting, TA = 0C to +85C 1667 1755 1843 VCHGIN = 5.0V, charger enabled, VBATT = 3.8V, 4000mA input current setting, TA = +25C 3800 3900 4000 VCHGIN = 5.0V, charger enabled, VBATT = 3.8V, 4000mA input current setting, TA = 0C to +85C 3705 3900 4095 mA mA WCIN, CHGIN Self-Discharge Down to UVLO Time tINSD Time required for the charger input to cause a 10F input capacitor to decay from 6.0V to 4.3V. 100 ms WCIN, CHGIN Input Self-Discharge Resistance RINSD For CHGIN, this resistor is disconnected from the CHGIN pin during MUIC microphone mode 35 k WCINOK/CHGINOK to Start Switching tSTART 150 ms www.maximintegrated.com Maxim Integrated 6 MAX77818 Dual Input, Power Path, 3A Switching Mode Charger with FG Switching Charger Electrical Characteristics (continued) (VCHGIN = 5V, VBATT = 4.2V, TA = -40C to +85C, unless otherwise noted. Typical values are at TA = 25C. Fast-charge current is set for 1.5A, done current is set for 150mA. Limits are 100% production tested at TA = +25C . Limits over the operating temperature range and relevant supply voltage range are guaranteed by design and characterization. Typical values are not guaranteed.) PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS 0.0144 0.04 SWITCH IMPEDANCES AND LEAKAGE CURRENTS CHGIN to BYP Resistance RIN2BYP WCIN to BYP Resistance Bidirectional RWCIN2BYP 0.093 0.26 CHGLX High-Side Resistance RHS 0.0327 0.1 CHGLX Low-Side Resistance RLS 0.0543 0.14 RBAT2SYS 0.0128 0.04 BATT to SYS Dropout Resistance CHGIN to BATT Dropout Resistance RIN2BAT Calculation estimates a 0.04 inductor resistance (RL) RIN2BAT = RIN2BYP + RHS +RL + RBAT2SYS CHGLX Leakage Current CHGLX = CHGPG or BYP BST Leakage Current VBST = 5.5V BYP Leakage Current VBYP = 5.5V, VCHGIN = 0V, VCHGLX = 0V, charger disabled 0.0999 TA = +25C 0.01 10 A TA = +85C 1 TA = +25C 0.01 TA = +85C 1 TA = +25C 0.01 TA = +85C 1 A A 10 A A 10 A WCIN Leakage Current VBYP = 0V, VCHGIN = 0V, VWCIN = 5.5V TA = +25C 0.01 A TA = +85C 1 A SYS Leakage Current VSYS = 0V, VBATT = 4.2V, charger disabled TA = +25C 0.01 TA = +85C 1 www.maximintegrated.com 10 A A Maxim Integrated 7 MAX77818 Dual Input, Power Path, 3A Switching Mode Charger with FG Switching Charger Electrical Characteristics (continued) (VCHGIN = 5V, VBATT = 4.2V, TA = -40C to +85C, unless otherwise noted. Typical values are at TA = 25C. Fast-charge current is set for 1.5A, done current is set for 150mA. Limits are 100% production tested at TA = +25C . Limits over the operating temperature range and relevant supply voltage range are guaranteed by design and characterization. Typical values are not guaranteed.) PARAMETER SYMBOL CONDITIONS VCHGIN = 0V, VSYS = 0V, VBATT = 4.2V, QBAT is off IMBAT VCHGIN = 0V, VBATT = 4.2V, QBAT is on, main-battery overcurrent protection disabled VCHGIN = 0V, VBATT = 4.2V, QBAT is on, main-battery overcurrent protection enabled BATT Quiescent Current (ISYS = 0A, IBYP = 0A ) VSYS = 4.2V, VBATT = 0V, charger disabled IMBDN VCHGIN = 5V, VBATT = 4.2V, QBAT is off, main-battery overcurrent protection disabled, Charger is enabled but in its done mode MIN TYP MAX UNITS TA = +25C 20 30 A TA = +85C 20 A TA = +25C 15.3 A TA = +85C 15.3 A TA = +25C 20 A TA = +85C 20 A TA = +25C 0.01 TA = +85C 1 TA = +25C 3 TA = +85C 3 A 10 A A 10 A CHARGER DC-DC BUCK Minimum On-Time tON-MIN 75 ns Minimum Off-Time tOFF 75 ns TA = 0C to +85C IND = 0 (0.47H inductor option) Production tested at ILIM = 00 setting (Note 7) Current Limit (Note 6) ILIM TA = 0C to +85C IND = 1 (1.0H inductor option) Production tested at ILIM = 11 setting (Note 7) www.maximintegrated.com ILIM = 00 (3.00A out) 4.15 5.05 ILIM = 01 (2.75A out) 4.75 ILIM = 10 (2.50A out) 4.45 ILIM = 11 (2.25A out) 4.15 ILIM = 00 (3.00A out) 4.60 ILIM = 01 (2.75A out) 4.30 ILIM = 10 (2.50A out) 4.00 ILIM = 11 (2.25A out) 5.95 A A 3.00 3.70 4.40 Maxim Integrated 8 MAX77818 Dual Input, Power Path, 3A Switching Mode Charger with FG Switching Charger Electrical Characteristics (continued) (VCHGIN = 5V, VBATT = 4.2V, TA = -40C to +85C, unless otherwise noted. Typical values are at TA = 25C. Fast-charge current is set for 1.5A, done current is set for 150mA. Limits are 100% production tested at TA = +25C . Limits over the operating temperature range and relevant supply voltage range are guaranteed by design and characterization. Typical values are not guaranteed.) PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS 5.75 V REVERSE BOOST 2.5V < VBATT < 4.5V. Adjustable from 3V to 5.75V, production tested at 3V, 5.0V and 5.75V settings BYP Voltage Adjustment Range Reverse Boost Quiescent Current Reverse Boost BYP Voltage in OTG Mode CHGIN Voltage in OTG Mode CHGIN Output Current Limit IBYP VBYP.OTG VCHGIN.OTG ICHGIN.OTG.LIM Reverse Boost Output Voltage Ripple 3 Not switching: output forced 200mV above its target regulation voltage 1150 5.1V setting 4.94 Mode = 0x05 or 0x0F, WCIN switch is on, VCHGIN_REG = 4.9V, RIN2WCIN + RDSCHGIN < 300mI, OTG load current 450mA 4.75 OTG_ILIM = 00 500 550 mA OTG_ILIM = 01 900 990 mA OTG_ILIM = 10 1200 1320 mA OTG_ILIM=11 1500 1650 mA 3.4V < VBATT < 4.5V, TA = +25C 5.1 A 5.26 V V Discontinuous inductor current (i.e., skip mode) 150 mV Continuous inductor current 150 mV CHARGER BATT Regulation Voltage Range VBATTREG Programmable in 25mV steps (4 bits), production tested at 3.65V and 4.4V only. 3.65 4.7 V TA = +25C -0.75 +0.75 % TA = 0C to +85C -1 +1 % 0 3 A TA = +25C -2.5 +2.5 % TA = 0C to +85C -5 +5 % -10 +10 % BATT Regulation Voltage Accuracy 3.65V and 4.7V settings Fast-Charge Current Program Range 0A to 3.0A in 50mA steps, production tested at 500,1000, 2000 and 3000mA settings Fast-Charge Current Accuracy Programmed currents 500mA, VBATT > VSYSMIN (short mode), production tested at 500mA, 800mA, 1000mA, 2000mA, 3000mA settings Programmed currents 500mA, VBATT < VSYSMIN (LDO mode), production test at 800mA www.maximintegrated.com Maxim Integrated 9 MAX77818 Dual Input, Power Path, 3A Switching Mode Charger with FG Switching Charger Electrical Characteristics (continued) (VCHGIN = 5V, VBATT = 4.2V, TA = -40C to +85C, unless otherwise noted. Typical values are at TA = 25C. Fast-charge current is set for 1.5A, done current is set for 150mA. Limits are 100% production tested at TA = +25C . Limits over the operating temperature range and relevant supply voltage range are guaranteed by design and characterization. Typical values are not guaranteed.) PARAMETER Fast-Charge Currents SYMBOL IFC CONDITIONS TA = +25C, VBATT > VSYSMIN MIN TYP MAX UNITS Programmed for 3.0A 2925 3000 3075 mA Programmed for 2.0A 1950 2000 2050 mA Programmed for 1.0A 975 1000 1025 mA Programmed for 0.5A 487.5 500 512.5 mA Low-Battery Prequalification Threshold VPQLB VBATT rising 2.8 2.9 3 V Dead-Battery Prequalification Threshold VPQDB VBATT rising 1.9 2 2.1 V Prequalification Threshold Hysteresis VPQ-H Applies to both VPQLB and VPQDB Low-Battery Prequalification Charge Current IPQLB Default setting = disabled Dead-Battery Prequalification Charge Current IPQDB Charger Restart Threshold Range VRSTRT Adjustable, 100, 150, and 200; it can also be disabled Charger Restart Deglitch Time 10mV overdrive, 100ns rise time Top-Off Current Program Range Programmable from 100 to 350mA in 8 steps. Top-Off Current Accuracy (Note 8) 100 mV 75 100 140 mA 40 55 80 mA 100 150 200 mV 130 100 ms 350 mA Gain 5 % Offset 20 mA Charge Termination Deglitch Time tTERM 2mV overdrive, 100ns rise/fall time 30 ms Charger State Change Interrupt Deglitch Time tSCIDG Excludes transition to timer fault state, watchdog timer state 30 ms 1.5 ms Charger Soft-Start Time www.maximintegrated.com tSS Maxim Integrated 10 MAX77818 Dual Input, Power Path, 3A Switching Mode Charger with FG Switching Charger Electrical Characteristics (continued) (VCHGIN = 5V, VBATT = 4.2V, TA = -40C to +85C, unless otherwise noted. Typical values are at TA = 25C. Fast-charge current is set for 1.5A, done current is set for 150mA. Limits are 100% production tested at TA = +25C . Limits over the operating temperature range and relevant supply voltage range are guaranteed by design and characterization. Typical values are not guaranteed.) PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS SMART POWER SELECTOR BATT to SYS Reverse Regulation Voltage VBSREG Minimum SYS Voltage Accuracy VSYSMIN Maximum SYS Voltage VSYSMAX IBATT = 10mA 30 mV IBATT = 1A 60 mV Load regulation during the reverse regulation mode 30 mV/A Programmable from 3.4V to 3.7V in 100mV steps, VBATT = 2.8V, tested at 3.4V and 3.7V settings -3 3 % The maximum system voltage: VSYSMAX = VBATREG + RBAT2SYS x IBATT VBATREG = 4.2V, IBATT = 3.0A 4.245 4.32 V The maximum system voltage: VSYSMAX = VBATREG + RBAT2SYS x IBATT. VBATREG = 4.7V, IBATT = 3.0A 4.745 4.82 V WATCHDOG TIMER Watchdog Timer Period tWD 80 Watchdog Timer Accuracy -20 s 0 +20 % CHARGE TIMER Prequalification Time tPQ Applies to both low-battery prequalification and dead-battery prequalification modes 35 min Fast-Charge Constant Current + Fast-Charge Constant Voltage Time tFC Adjustable from 4hrs to 16hrs in 2 hour steps including a disable setting 8 hrs Top-Off Time tTO Adjustable from 0min to 70min in 10min steps 30 min Timer Accuracy -20 +20 % AVL FILTER Internal AVL Filter Resistance www.maximintegrated.com 12.5 Maxim Integrated 11 MAX77818 Dual Input, Power Path, 3A Switching Mode Charger with FG Switching Charger Electrical Characteristics (continued) (VCHGIN = 5V, VBATT = 4.2V, TA = -40C to +85C, unless otherwise noted. Typical values are at TA = 25C. Fast-charge current is set for 1.5A, done current is set for 150mA. Limits are 100% production tested at TA = +25C . Limits over the operating temperature range and relevant supply voltage range are guaranteed by design and characterization. Typical values are not guaranteed.) PARAMETER SYMBOL CONDITIONS MIN TJREG Junction temperature when charge current is reduced. Programmable from +85C to +130C in 15C steps, default value is +100C 85 ATJREG The charge current is decreased 6.7% of the fast charge current setting for every degree that the junction temperature exceeds the thermal regulation temperature. This slope ensures that the full-scale current of 3.0A is reduced to 0A by the time the junction temperature is 20C above the programmed loop set point. For lower programmed charge currents such as 500mA, this slope is valid for charge current reductions down to 100mA; below 100mA the slope becomes shallower but the charge current still reduced to 0A if the junction temperature is 20C above the programmed loop set point. TYP MAX UNITS 130 C THERMAL FOLDBACK Junction Temperature Thermal Regulation Loop Setpoint Program Range Thermal Regulation Gain -150 mA/C BATTERY OVERCURRENT PROTECTION Battery Overcurrent Threshold Range IBOVCR Programmable from 3.0A to 4.5A in 0.25A steps, can be disabled 3 Battery Overcurrent Debounce Time tBOVRC This is the response time for generating the overcurrent interrupt flag 3 Battery Overcurrent Protection Quiescent Current IBOVRC System Power-Up Current ISYSPU System Power-Up Voltage VSYSPU VSYS rising, 100mV hysteresis System Power-Up Response Time tSYSPU Time required for circuit to activate from an unpowered state (i.e., main-battery hot insertion) 6 4.5 A 10 ms 3+ IBATT /22000 A 35 50 80 mA 2 2.1 2.2 V 1 s BATT Self-Discharge Resistor 600 SYS Self-Discharge Resistor 600 Self-Discharge Latch Time 300 ms SYSTEM SELF DISCHARGE WITH NO POWER www.maximintegrated.com Maxim Integrated 12 MAX77818 Dual Input, Power Path, 3A Switching Mode Charger with FG Switching Charger Electrical Characteristics (continued) (VCHGIN = 5V, VBATT = 4.2V, TA = -40C to +85C, unless otherwise noted. Typical values are at TA = 25C. Fast-charge current is set for 1.5A, done current is set for 150mA. Limits are 100% production tested at TA = +25C . Limits over the operating temperature range and relevant supply voltage range are guaranteed by design and characterization. Typical values are not guaranteed.) PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS DETBATB, INOKB, WCINOKB DETBATB Logic Threshold Logic Input Leakage Current VIH 0.8 x VIO 4% hysterisis IDETBATB 0.1 Output Low Voltage INOKB, WCINOKB ISINK = 1mA Output High Leakage INOKB, WCINOKB VSYS = 5.5V TA = +25C -1 TA = +85C 0 V 1 A 0.4 V +1 A 0.1 A Safeout LDOs Electrical Characteristics (VSYS = 2.8V to 4.5V, TA = -40C to 85C, typical values are at TA = +25C, unless otherwise noted. Limits are 100% production tested at TA = +25C . Limits over the operating temperature range and relevant supply voltage range are guaranteed by design and characterization. Typical values are not guaranteed.) PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS 4.8 4.9 5 V SAFEOUT1 5V < VCHGIN < 5.5V, IOUT = 10mA, SAFEOUT1 = 01 (default) Output Voltage (Default On) SAFEOUT1 = 00 4.85 V SAFEOUT1 = 10 4.95 V SAFEOUT1 = 11 3.3 V Maximum Output Current 60 Output Current Limit 60 mA 150 320 mA Dropout Voltage VCHGIN = 5V, IOUT = 60mA 120 mV Load Regulation VCHGIN = 5.5V, 30A < IOUT < 30mA 50 mV Quiescent Supply Current Not production tested 72 A Output Capacitor for Stable Operation (Note 9) 0A < IOUT < 30mA, MAX ESR = 50m 1 F Minimum Output Capacitor for Stable Operation (Note 9) 0A < IOUT < 30mA, MAX ESR = 50m 0.7 F 1200 Internal Off-Discharge Resistance www.maximintegrated.com Maxim Integrated 13 MAX77818 Dual Input, Power Path, 3A Switching Mode Charger with FG Safeout LDOs Electrical Characteristics (continued) (VSYS = 2.8V to 4.5V, TA = -40C to 85C, typical values are at TA = +25C, unless otherwise noted. Limits are 100% production tested at TA = +25C . Limits over the operating temperature range and relevant supply voltage range are guaranteed by design and characterization. Typical values are not guaranteed.)) PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS 4.8 4.9 5 V SAFEOUT2 5V < VCHGIN < 5.5V, IOUT = 10mA, SAFEOUT2 = 01 (default) Output Voltage (Default Off) SAFEOUT2 = 00 4.85 V SAFEOUT2 = 10 4.95 V SAFEOUT2 = 11 3.3 V Maximum Output Current 60 Output Current Limit 60 mA 150 320 mA Dropout Voltage VCHGIN = 5V, IOUT = 60mA 120 mV Load Regulation VCHGIN = 5.5V, 30A < IOUT < 30mA 50 mV Quiescent Supply Current Not production tested 72 A Output Capacitor for Stable Operation (Note 9) 0A < IOUT < 30mA, MAX ESR = 50m 1 F Minimum Output Capacitor for Stable Operation (Note 9) 0FA < IOUT < 30mA, MAX ESR = 50m 0.7 F 1200 Internal Off-Discharge Resistance Note 9: Not production tested. Fuel Gauge Electrical Characteristics (VSYS = 2.8V to 4.5V, TA = -40C to 85C, typical values are at TA = +25C, unless otherwise noted. Limits are 100% production tested at TA = +25C . Limits over the operating temperature range and relevant supply voltage range are guaranteed by design and characterization. Typical values are not guaranteed.) PARAMETER Supply Current SYMBOL CONDITIONS MIN TYP IDD0 Fuel gauge shut down (Note 10) 0.5 IDD1 Fuel gauge active, average with 7.5% ADC duty cycle (Note 10) 35 ADC Duty Cycle Duty Parameter Capture Rate tACQ Regulator Output VBFG Period of ADC activation loop 1.5 MAX UNITS A 70 A 7.5 % 0.1758 s 1.8 1.98 V VOLTAGE CHANNEL VBATT Measurement Error VBATT Measurement Resolution VBATT Measurement Range www.maximintegrated.com VGERR VBATT = 2.8V to 4.5V, TA = +25C -7.5 +7.5 mV TA = -40C to +85C -20 +20 mV VLSB VRANGE 1.25 2.8 mV 4.98 V Maxim Integrated 14 MAX77818 Dual Input, Power Path, 3A Switching Mode Charger with FG Fuel Gauge Electrical Characteristics (continued) (VSYS = 2.8V to 4.5V, TA = -40C to 85C, typical values are at TA = +25C, unless otherwise noted. Limits are 100% production tested at TA = +25C . Limits over the operating temperature range and relevant supply voltage range are guaranteed by design and characterization. Typical values are not guaranteed.) PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS CURRENT CHANNEL Current Measurement Resolution ILSB 1.25 Current Measurement Range IRANGE Current Measurement Offset IOERR Long term average at zero input current Current Measurement Symmetrical Error ISERR (Notes 11, 12, 13) Current Measurement Asymmetrical Error Linear Regulator Mode Current Measurement Error Time-Base Accuracy -3.6 3000mA IAERR ILRERR tERR mA 1000mA (Notes 12, 13, 14) +3.6 0.25 mA 2% % -150 +150 -20 +20 300mA -9.5 +9.5 +1500mA -225 +225 -40 +40 +100mA (Note 15) VSYS = 3.7V at TA = +25C A 1 TA = -40C to +85C -3.5 +3.5 (Note 13) -0.5 +0.5 mA mA % THERMAL CHANNEL Ratiometric Measurement Accuracy, THM TGERR Ratiometric Measurement Resolution, THM TLSB THMB Output Drive VOH_THMB THMB Precharge Time tPRE_THMB THMB Operating Range VTHMB THMB Input Leakage IIN_THMB THM Input leakage IIN_THM www.maximintegrated.com % of full scale 0.0244 IOH_THMB = -0.5mA VAVL 0.1 V 12.7 VTHMB = 5V % of full scale ms 2.8 VAVL V -1 +1 A -1 +1 A Maxim Integrated 15 MAX77818 Dual Input, Power Path, 3A Switching Mode Charger with FG Electrical Characteristics (continued) Note Note Note Note Note Note Note Note Note Note Note Note 2: 3: 4: 5: Design guidance only, not tested during final test. Input filters on the SDA and SCL inputs suppress noise spikes of less than 50ns. The CHGIN input must be less than VOVLO and greater than both VCHGIN_UVLO and VCHGIN2SYS for the charger to turn-on. The input voltage regulation loop decreases the input current to regulate the input voltage at VCHGIN_REG. If the input current is decreased to ICHGIN_REG_OFF and the input voltage is below VCHGIN_REG, then the charger input is turned off. 6: Production tested to 1/4 of the threshold with LPM bit = 1 (1/4 FET configuration). 7: Production tested in charger DC-DC low-power mode (CHG_LPM bit = 1). 8: Not production tested. Note 10: The total chip supply current includes the charger supply current in addition to the supply current for the fuel gauge. 11: Symmetrical error is the sum of odd order errors in the measured values at two inputs symmetrical around zero; for example, ISERR_0.3A = (Error 0.3A - Error -0.3A)/2/0.3A x 100. 12:Total current measurement error is the sum of the symmetrical and asymmetrical errors. Fuel gauge accuracy is sensitive to asymmetrical error but insensitive to symmetrical error. 13:Current and ratiometric measurement errors are production tested at VSYS = 3.7V and guaranteed by design at VSYS = 2.8V and 4.5V. 14:Asymmetrical error is the sum of even order errors in the measured values at two inputs symmetrical around zero; for example IAERR_0.3A = (Error 0.3A + Error -0.3A)/2. 15:Total linear regulator mode current measurement error is simply the total error with respect to the input. This mode exists for a short duration when charging an empty battery, hence this error has limited consequence. www.maximintegrated.com Maxim Integrated 16 MAX77818 Dual Input, Power Path, 3A Switching Mode Charger with FG Pin Configuration TOP VIEW (BUMP SIDE DOWN) MAX77818 1 2 3 4 5 6 7 8 9 A N.C. TEST4 SDA SCL WCINOKB GND_Q WCIN WCIN N.C. B VCC_TEST TEST3 TEST5 TEST6 VIO DETBATB SAFEOUT2 BYP SAFEOUT1 C TEST1 TEST2 INTB N.C. INOKB N.C. BYP CHGIN CHGIN D GND_A GND_A GND_A GND_A GND_A AVL BYP CHGIN CHGIN E SYS_A N.C. GND_D N.C. SYS N.C. PVL BYP BYP F VBFG SYS_A N.C. N.C. SYS BAT_SN BST CHGLX CHGLX G THMB N.C. BATT BATT SYS BAT_SP CHGR GSUB CHGLX CHGLX H N.C. THM BATT BATT SYS SYS CHGPG CHGPG CHGPG + WLP (72 BUMPS WLP 9X8 BUMP ARRAY 0.4MM PITCH) N/C PINS ARE FLOATING AND CAN BE CONNECTED AT BOARD-LEVEL IF NEEDED. ALL TEST PINS (TEST1-6 AND VCCTEST) SHOULD BE GROUNDED IN THE END-USE APPLICATION. *TOP VIEW = WAFER BACK-SIDE VIEW (BUMPS NOT VIEWABLE) www.maximintegrated.com Maxim Integrated 17 MAX77818 Dual Input, Power Path, 3A Switching Mode Charger with FG Pin Description PIN NAME A1, A9, C4, C6, E2, E4, E6, F3, F4, G2, H1 N.C. A2 TEST4 A3 SDA I2C Serial Data. Add an external 2.2k pullup resistor to VIO. A4 SCL I2C Serial Clock. Add an external 2.2k pullup resistor to VIO. A5 WCINOKB A6 GND_Q A7, A8 WCIN B1 VCCTEST B2 TEST3 Test I/O. Ground this pin in the application. B3 TEST5 Test I/O. Ground this pin in the application. B4 TEST6 Test I/O. Ground this pin in the application. B5 VIO B6 DETBATB B7 SAFEOUT2 FUNCTION No Connection Test I/O Pin. Ground this pin in the application. Wireless Charger Input Valid, Active-Low Logic Output Flag. Open-drain, active-low output that indicates when valid voltage is present at WCIN and SYS. Quiet Ground. Short to GND_A and GND_D. Wireless Charger Input. 6VDC protected input pin connected to Wireless charger power source. The wireless charger may be active during OTG mode, or disabled using the WCINSEL bit. Connect a 4.7F/10V ceramic capacitor from WCIN to GND plane Test Mux Supply. Ground this pin in the application. Digital I/O Supply Input for I2C Interface. Battery Detection Active-Low Input. Connect this pin to the ID pin on the battery pack. If DETBATB is pulled below 80% of the externally applied VIO voltage, this is an indication that the battery is present and the charger starts when valid CHGIN and/or WCIN power is present. If DETBATB is driven high to VIO voltage or left unconnected, this is an indication that the battery is not present and the charger does not start. DETBATB is pulled high to VIO pin through an off-chip pullup resistor. Safeout LDO2 Output. Default off. Bypass with a 1F ceramic capacitor to GND. CHGIN Bypass. This pin can see up to OVP limit. Output of adapter Input current Limit block and input to switching charger. BYP is also the boost converter output when the charger is operating in reverse boost mode. Bypass with 2x10F/16V ceramic capacitors from BYP to CHGPG ground plane. B8, C7, D7, E8, E9 BYP B9 SAFEOUT1 C1 TEST1 Test I/O. Ground this pin in the application. C2 TEST2 Test I/O. Ground this pin in the application. C3 INTB C5 INOKB www.maximintegrated.com Safeout LDO1 Output. Default 4.9V and on when CHGIN power is valid. Bypass with a 1F ceramic capacitor to GND. Interrupt Output. Active-low, open-drain output. Add a 200k pullup resistor to VIO. Charger Input Valid, Active-Low Logic Output Flag. Open-drain output indicates when valid voltage is present at both CHGIN and SYS or WCIN and SYS. Maxim Integrated 18 MAX77818 Dual Input, Power Path, 3A Switching Mode Charger with FG Pin Description (continued) PIN NAME C8, C9, D8, D9 CHGIN Charger Input. The adapter/USB charger input may be active, or disabled using the CHGINSEL bit. Connect a 2.2F/16V ceramic capacitor from CHGIN to GND plane. D1-D5 GND_A Analog Ground. Short to GND_D and GND_Q. E3 GND_D Digital Ground. Short to GND_A and GND_Q. D6 AVL E1, F2 SYS_A E5, F5, G5, H5, H6 SYS System Power Connection. Connect system loads to this node. Bypass with 2x10F ceramic capacitors from SYS to CHGPG ground plane. E7 PVL Internal Bias Regulator High-Current Output Bypass. Supports internal noisy and high-current gate drive loads. Bypass to GND with a minimum 10F/10V ceramic capacitor. F1 VBFG 1.8V power supply output for Fuel Gauge. Bypass VBFG with a 0.1F ceramic capacitor, VBFG is not intended to power external circuitry. F6 BAT_SN Battery Negative Differential Sense Connection. Connect to the negative or ground terminal close to the battery. F7 BST F8, F9, G8, G9 CHGLX G1 THMB Pullup Voltage for THM Pin Pullup Resistor. Can be switched to save power. G3, G4, H3, H4 BATT Battery Power Connection. Connect to the positive terminal of a single-cell (or parallel cell) Li Ion battery. Bypass BATT to CHGPG ground plane with a 10F ceramic capacitor. G6 BAT_SP G7 CHGRGSUB H2 THM H7-H9 CHGPG www.maximintegrated.com FUNCTION Analog Voltage Level. Output of on-chip 5V LDO used to power on-chip, low-noise circuits. Bypass with a 2.2F/10V ceramic capacitor to GND. Powering external loads from AVL is not recommended, other than pulldown resistors. Analog SYS Input High-Side FET Driver Supply. Bypass BST to LX with a 0.1F ceramic capacitor. Charger Switching Node. Connect the inductor between CHGLX and SYS. Battery Positive Differential Sense Connection. Connect to the positive terminal close to the battery. Substrate Charger Ground Connection. Connect with GND_A. Thermistor Connection. Determines battery temperature using ratiometric measurement. Charger Power Ground Connection Maxim Integrated 19 MAX77818 Dual Input, Power Path, 3A Switching Mode Charger with FG Block Diagram VBUS 4 CHGIN 2 WCIN MAX77818 BYP 2.2F /16V FROM WC PAD BST 0.1F PVL 4.7F /10V 10F /10V MICRO USB CONNECTOR CHGLX AVL VSYS 2 x 10F/16V 5 CHARGER INPUT SENSE AND CONTROL 2.2F /10V VIO 4 0.47H CHGRGSUB 2 x 10F/10V CHARGER SW CONTROL, REVERSE BOOST, FUEL GUAGE INOKB WCINOKB CHGPG 3 SYS 5 VSYS VIO GND VIO REVERSE BLOCKING VIO 1F /6.3V SDA SCL AP BATT I2C INTERFACE AND LOGIC CONTROL 10F/ 10V BAT_SP FUEL GAUGE mg5 INTB AP SAFEOUT1 1F /10V CP SAFEOUT2 1F /10V VSYS 2 BAT_SN 5V USBLDO THM 5V USBLDO THMB SYS_A VCCTEST 6 TEST_ 4 10k DETBAT VBFG TEST 0.1F GND_A GND_Q 5 Detailed Description System Faults MAX77818 monitors the system for the following faults: VSYS undervoltage lockout GND_D N.C. 11 when 0 < SYS < DEADBAT (= 2.0V), QBAT is off, but the charger pulls up SYS from BAT with a constant current of 50mA. when charger input is invalid and battery is present. VSYS overvoltage lockout when DEADBAT < SYS < UVLO (= 2.5V), QBAT is on and SYS is shorted to BAT. VSYS Fault when 0 < SYS < DEADBAT (= 2.0V), QBAT is off. The system monitors the VSYS node for undervoltage and overvoltage. The following describes the IC behavior if any of these events is to occur. VSYS Undervoltage Lockout (VSYSUVLO) When charger input is valid and SYS node falls below SYS UVLO, all charger and fuel gauge O type registers are reset and following happen: when DEADBAT < SYS < UVLO (= 2.5V), QBAT is on and SYS is shorted to BAT. www.maximintegrated.com VSYS Overvoltage Lockout (VSYSUVLO) The absolute maximum ratings state that the SYS node withstands up to 6V. The SYS OVLO threshold is set to 5.36V (typ). Ideally, VSYS should not exceed the battery charge termination threshold. Systems must be designed so that VSYS never exceeds 4.8V (transient and steadstate). If the VSYS should exceed VSYSOVLO during a fault, the MAX77818 resets the charger and fuel gauge O type registers. Maxim Integrated 20 MAX77818 INTB The MAX77818 uses one interrupt pin: INTB. The interrupt is meant to indicate to the application processor that the status of MAX77818 has changed. The INTB signal is asserted whenever one or more interrupts are toggled, and those interrupts are not masked. The application processor reads the interrupts in two steps. First, the AP reads the INTSRC register. This is a read-only register that indicates which functional block is generating the interrupt (i.e., charger and FG). Depending on the result of the read, the next step is to read the actual interrupt registers pertaining to the functional block. For example, if the application processor reads 0x02 from INTSRC register, it means the top-level MAX77818 block has an interrupt generated. The next step is to read the related interrupt register of the MAX77818 functional block. The INTB pin becomes high (cleared) as soon as the read sequence of the last INT_ register that contains an active interrupt starts. FG interrupts are cleared by setting new threshold values. All interrupts can be masked to prevent the INTB from being asserted for masked interrupts. A mask bit in the INTM register implements masking. The INTSRC register can still provide the actual interrupt status of the masked interrupts, but the INTB pin is not asserted. Charger, Safeout LDO, and Charger Type Detection Interaction The charger type detection circuit performs charger type detection and gates whether or not the charger is enabled. The charger type detection circuit allows the charger to be enabled once charge detection is complete, depending on the type of charger detected and whether or not it is USB 2.0 compliant. A manual override bit allows the user to enable the charger regardless of the charger type detection circuit charger detection status. SAFEOUT1 is enabled by default once charger detection is complete and CHGIN is valid regardless of DETBATB. SAFEOUT2 can also be enabled once the same conditions are met, and the user sets the ENSAFEOUT2 register bit. Dual Input, Power Path, 3A Switching Mode Charger with FG Switching Mode Charger Features: Complete Li+/Li-poly battery charger Prequalification, constant current, constant voltage 55mA dead-battery prequalification 100mA low-battery prequalification current Adjustable constant current charge * 0A to 3.0A in 50mA steps * 5% accuracy Adjustable charge termination threshold * 100mA to 200mA in 25mA steps and 200mA to 350mA in 50mA steps * 5% accuracy Adjustable battery regulation voltage * 3.625V to 4.700V in 25mV steps * 0.5% accuracy at T = +25C * 1% accuracy * Remote differential sensing Synchronous switch-mode design Reverse boost mode with adjustable VBYP from 3.0V to 5.8V Smart Power SelectorTM * Optimally distributes power between charge adapter, system, and main battery * When powered by a charge adapter, the main battery can provide supplemental current to the system * The charge adapter and can support the system without a main battery No external MOSFETs required Dual input * Reverse leakage protection prevents the battery leaking current to the inputs * 4.0A adapter input * 16V withstand, 14V operating * Adjustable input current limit (100mA to 4.0A in 33.3mA steps (CHGIN_ILIM), 500mA default) * Support AC-to-DC wall warts and USB adapters * 1.26A wireless charger input * 6V fault tolerant * Adjustable input current limit (60mA to 1.26A in 20mA steps (WCIN_ILIM), 500mA default) Smart Power Selector is a trademark of Maxim Integrated Products, Inc. www.maximintegrated.com Maxim Integrated 21 MAX77818 Dual Input, Power Path, 3A Switching Mode Charger with FG Charge safety timer * Selectable: 4hr to 16hr in 2hr steps plus a disable setting Short-circuit protection * Programmable BAT to SYS overcurrent threshold from 3.0A to 4.5A in 0.25A steps plus a disable setting * DISIBS bit allows the host to disable the battery to system discharge path to protect against a shortcircuit * SYS short to ground * BUCK current is limited by by the ILIM current limit. BATT currents above the programmed by B2SOVRC threshold generate an interrupt. The host can then disable the battery to system discharge path by setting DISIBS. Die temperature monitor with thermal foldback loop * Selectable die temperature thresholds (C): 70, 85,100, and 115 Input voltage dropout control allows operation from high-impedance sources. Charge current is reduced so input is not pulled below 4.3V. BATT to SYS switch is 12.8m (typ). Dead battery detection VUSB/VADP CHGIN BYP BST +3.2V TO +14V OPERATING UP TO 4.0A INPUT CURRENT WIRELESS WCIN MAX77818 CHGIN VBYP 5.05V (REVERSE BOOST MODE) CHGIN INPUT CURRENT LIMIT SWITCH BUCK/BOOST CONTROLLER WCIN AVL WCIN INPUT CURRENT LIMIT AND 5.9V OVERVOLTAGE SWITCH PVL CHGLX VSYS CHGPGND SYS CHARGE AND SMART POWER PATH CONTROLLER REVERSE BLOCKING BATT UP TO 3.0A CHARGE CURRENT Figure 1. Simplified Charger Functional Diagram www.maximintegrated.com Maxim Integrated 22 MAX77818 Dual Input, Power Path, 3A Switching Mode Charger with FG RINSD VUSB/VADP +3.2V TO +14V OPERATING UP TO 4.0A INPUT CURRENT VUSB/VADP VBYP QCHGIN BYP CHGIN 4.7uF 25V 0603 QWCIN REG WCIN 10uF 6.3V 0603 AVL BYP 2x10uF 25V 0603 2.2uF 10V 0402 VCHGIN PVL INPUT CONTROL 2.2uF 10V 0402 WATCHDOG CHARGE TIMER MAX77818 BST 4MHZ BUCK CONTROLLER CONTROL REGISTERS CHARGE CONTROLLER 0.1uF 6.3V 0402 QHS CHGLX DRV_OUT 0.47uH QLS REVERSE BOOST CONTROLLER CHGPGND TJ JUNCTION TEMPERATURE SENSOR TEMP. TO SYSTEM UP TO 7.5A TOTAL (3.0A FROM THE INPUT AND 4.5A FROM BATTERY.) SYS VSYS 2x4.7uF 6.3V 0402 QBAT REVERSE BLOCKING VIMBAT BATT 1.0F UP TO 3.0A OF 6.3V CHARGE 0402 CURRENT AND UP TO 4.5A OF DISCHARGE CURRENT ID MBATT DETBATB BAT_SP VMBATT SYS BAT_SN + ID BATTGND Figure 2. Main Battery Charger Detailed Functional Diagram www.maximintegrated.com Maxim Integrated 23 MAX77818 Detailed Description The MAX77818 includes a full-featured switch-mode charger for a one-cell lithium ion (Li+) or lithium polymer (Li-poly) battery. As shown in Figure 2, the current limit for CHGIN input is independently programmable from 0 to 3.0A in 33.3mA steps allowing the flexibility for connection to either an AC-to-DC wall charger or a USB port. CHGIN current limit default is set between 100mA and 500mA with 500mA being the programmed default. The synchronous switch-mode DC-DC converter utilizes a high 4.0MHz switching frequency which is ideal for portable devices because it allows the use of small components while eliminating excessive heat generation. The DC-DC has both a buck and a boost mode of operation. When charging the main battery the converter operation as a buck. The DC-DC buck operates from a 3.2V to 14V source and delivers up to 3.0A to the battery. Battery charge current is programmable from 0A to 3.0A. As a boost converter, the DC-DC uses energy from the main battery to boost the voltage at BYP. The boosted BYP voltage is useful to provide the supply the USB OTG voltage. Maxim's Smart Power Selector architecture makes the best use of the limited adapter power and the battery's power at all times to supply up to 3.0A continuous (4A peak) from the buck to the system. Additionally, supplement mode provides additional current from the battery to the system up to 4.5ARMS. Adapter power that is not used for the system goes to charging the battery. All power switches for charging and switching the system load between battery and adapter power are included on chip. No external MOSFETs are required. Maxim's proprietary process technology allows for lowRDSON devices in a small solution size. The total dropout resistance from adapter power input to the battery is 0.0999 (typ) assuming that the inductor has 0.04 of ESR. This 0.0999 typical dropout resistance allows for charging a battery up to 3.0A from a 5V supply. The resistance from the BATT to SYS node is 0.0128, allowing for low power dissipation and long battery life. A multitude of safety features ensures reliable charging. Features include a charge timer, watchdog, junction thermal regulation, over/undervoltage protection, and shortcircuit protection. The BATT to SYS switch has overcurrent protection. See the Main battery Overcurrent Protection section for more information. Dual Input, Power Path, 3A Switching Mode Charger with FG Smart Power Selector The Smart Power Selector architecture is a network of internal switches and control loops that distributes energy between an external power source CHGIN, BYP, SYS, and BATT. Figure 1 shows a simplified arrangement for the smart power selector's power steering switches. Figure 2 shows a more detailed arrangement of the smart power selector switches and gives them the following names: QCHGIN, QHS, QLS, and QBAT. Switch and Control Loop Descriptions Input Switch: QCHGIN provides the input current limit. The input switch is completely on and does not provide forward blocking. As shown in Figure 2, there are SPS control loops that monitor the current through the input switches as well as the input voltage. DC-DC Switches: QHS and QLS are the DC-DC switches that can operate as a buck (step-down) or a boost (stepup). When operating as a buck, energy is moved from BYP to SYS. When operating as a boost, energy is moved from SYS to BYP. SPS control loops monitor the DC-DC switch current, the SYS voltage, and the BYP voltage. Battery-to-System Switch: QBAT controls the battery charging and discharging. Additionally QBAT allows the battery to be isolated from the system (SYS). An SPS control loop monitors the QBAT current. Control Bits MODE configures the Smart Power Selector. MINVSYS sets the minimum system voltage. VBYPSET sets the BYP regulation voltage target. B2SOVRC configures the main battery overcurrent protection. Energy Distribution Priority: With a valid external power source: The external power source is the primary source of energy. The main battery is the secondary source of energy. Energy delivery to BYP is the highest priority. Energy delivery to SYS is the second priority. Any energy that is not required by BYP or SYS is available to the main battery charger. With no power source available at CHGIN: The main battery is the primary source of energy. Energy delivery to BYP is the highest priority. www.maximintegrated.com Maxim Integrated 24 MAX77818 BYP includes the CHGIN if they are asked to supply energy in a USB OTG type of application. Energy delivery to SYS is the second priority. BYP Regulation Voltage When the DC-DC is enabled in boost only mode (MODE = 0x08), the voltage from BYP to ground (VBYP) is regulated to VBYPSET. When the DC-DC is enabled in one of its USB OTG modes (MODE = 0x09 or MODE = 0x0A), VBYP is set for 5.1V (VBYP.ORG). When the DC-DC is off or in one of its buck modes (MODE = 0x00 or MODE = 0x04 or MODE = 0x05) and there is a valid power source at CHGIN, VBYP = VCHGIN ICHGIN x RQCHGIN When the DC-DC is off and there is no valid power source at CHGIN, BYP is connected to SYS with an internal 200 resistor. This 200 resistor keeps BYP biased as SYS and allows for the system to draw very light loads from BYP. IF the system loading on BYP is more than 1.0mA then the DC-DC should be operated in boost mode. Note that the inductor and the high-side switch's body diode are in parallel with the 200 from SYS to BYP. SYS Regulation Voltage When the DC-DC is enabled as a buck and the charger is disabled (MODE = 0x04), VSYS is regulated to VBATREG (CHG_CV_PRM) and QBAT is off. When the DC-DC is enabled as a buck and the charger enabled but in a non-charging state such as done, watchdog suspend or timer fault (MODE = 0x05 and not charging), VSYS is regulated to VBATREG (CHG_CV_PRM) and QBAT is off. When the DC-DC is enabled as a buck and charging in prequalification, fast-charge, or top-off modes (MODE = 0x05 and charging), VSYS is regulated to VSYSMIN when the VBATT < VSYSMIN; in this mode the QBAT switch acts like a linear regulator and dissipates power [P = (VSYSMIN - VBATT) x IBATT]. When VBATT>VSYSMIN, then VSYS = VBATT - IBATT x RBAT2SYS; in this mode the QBAT switch is closed. In all of the above modes, if the combined SYS and BYP loading exceed the input current limit, then VSYS drops to VBATT - VBSREG and the battery provides supplemental current. If the fuel gauge requests main battery information (voltage and current) during this supplement mode, then the QBAT switch is closed (VSYS = VBATT - IBATT x RBAT2SYS) during the fuel gauge sample. If the fuel www.maximintegrated.com Dual Input, Power Path, 3A Switching Mode Charger with FG gauge wants requests continuous samples from the main battery during supplement mode, then the QBAT switch eventually opens when IBATT decreases below 40mA. When the DC-DC is enabled as a boost (MODE = 0x08 or 0x09 or 0x0A), then the QBAT switch is closed and VSYS = VBATT - IBATT x RBAT2SYS Battery Detect Input Pin (DETBATB) DETBATB is tied to the ID pin of the battery pack. If DETBATB is pulled below 80% of VIO pin voltage, this is an indication that the main battery is present and the battery charger starts upon valid CHGIN. If DETBATB is left unconnected or equal to VIO voltage, this indicates that the battery is not present and the charger does not start upon valid CHGIN, see Figure 3. The DETBATB is internally pulled to BATT through an external resistor. DETBATB status bit is valid when BATT is not present. Input Validation As shown in Figure 4, the charger input is compared with several voltage thresholds to determine if it is valid. A charger input must meet the following three characteristics to be valid: CHGIN must be above VCHGIN_UVLO to be valid. CHGIN must be below its overvoltage lockout threshold (VOVLO). CHGIN must be above the system voltage by VCHGIN2SYS. CHGIN input generates a CHGIN_I interrupt when its status changes. The input status can be read with CHGIN_OK and CHGIN_DTLS. Interrupts can be masked with CHGIN_M. VIO MAX77818 VCC 2R RBIAS 8R DETBATB GND RP VCC SYSTEM IC ID ADC BATTERY PACK NEG- Figure 3. DETBATB Internal Circuitry and System Diagram Maxim Integrated 25 MAX77818 Dual Input, Power Path, 3A Switching Mode Charger with FG INPUT IS OVERVOLTAGE CHGIN VCHGIN_OVLO VVCHGINOVLO INPUT IS UNDERVOLTAGE VCHGIN VCHGINUVLO VCHGIN2SYS LOW INPUT TO SYS HEADROOM BAT VCHGIN_UVLO VCHGIN IS INVALID VCHGIN_INVLD LIN2SYS Figure 4. Charger Input Validation Input Current Limit The default settings of the CHGIN_ILIM and MODE control bits are such that when a charge source is applied to CHGIN, the MAX77818 turns its DC-DC converter on in BUCK mode, limit VSYS to VBATREG, and limit the charge source current to 500mA. All control bits are reset on global shutdown. Input Voltage Regulation Loop An input voltage regulation loop allows the charger to be well behaved when it is attached to a poor quality power source (CHGIN pin) or wireless charger (WCIN pin). The loop improves performance with relatively high-resistance charge sources that exist when long cables are used or devices are charged with noncompliant USB hub configurations. Additionally, this input voltage regulation loop improves performance with current limited adapters. If the MAX77818's input current limit is programmed above the current limit threshold of given adapter, the input voltage loop allows the MAX77818 to regulate at the current limit of the adapter. Finally, the input voltage regulation loop allows the MAX77818 to perform well with adapters that have poor transient load response times. The input voltage regulation loop automatically reducing the input current limit in order to keep the input voltage at VCHGIN_REG, VWCIN_REG. If the input current limit is reduced to ICHGIN_REG_OFF (50mA typ) and the input voltage is below VCHGIN_REG, then the charger input is turned off. VCHGIN_REG, VWCIN_REG is programmable with VCHGIN_REG and VWCIN_REG. After operating with the input voltage regulation active, a BYP_I interrupt is generated, BYP_OK is cleared and www.maximintegrated.com BYP_DTLS = 0b1xxx. To optimize input power when working with a current limited charge source, monitor the BYP_DTLS while decreasing the input current limit. When the input current limit is set below the limit of the adapter, the input voltage rises. Although the input current limit is lowered, more power can be extracted from the input source when the input voltage is allowed to rise. Example 1: Optimum use of the input voltage regulation loop along with a current limited adapter. Sequence of Events VBATT = 3.2V, the system is operating normally A 5.0V 1.2A current limited dedicated USB charger is applied to CHGIN. The DC-DC buck regulator turns on, VSYS is regulated to VBATREG (4.2V) and the input is allowed to provide 100mA to the system. The system detects that the charge source is a dedicated USB charger and enables the battery charger (MODE = 0x05) and programs an input current limit to 1.8A (CHGIN_ILIM = 0x36 = 1.8A). The input current limit starts to ramp up from 100mA to 1.8A, but at the input current limit of the adapter (1.2A), the adapter voltage collapses. The MAX77818's inputvoltage regulation loop prevents the adapter voltage from falling below 4.3V (VCHGIN_REG = 4.3V). A BYP_I interrupt is generated and BYP_DTLS3 is set. With the input voltage regulation loop active, the adapter provides 1.2A at 4.3V, which is a total of 5.04W being delivered to the system. Maxim Integrated 26 MAX77818 Dual Input, Power Path, 3A Switching Mode Charger with FG The system software detects that the input voltage regulation loop is active and it begins to ramp down the programmed input current limit. When the current limit ramps down to 1.167A (CHGIN_ILIM), the adapter is no longer in current limit and the adapter voltage increases from 4.3V to 5.0V. With the adapter operating just below its current limit, it provides 1.167A at 5.0V which is a total of 5.84W to the system. This is 800mW more than when the adapter was in current limit. Input Self-Discharge for Reliable Charger Input Interrupt To ensure that a rapid removal and reinsertion of a charge source always results in a charger input interrupt, the charger input presents loading to the input capacitor to ensure USB CONNECTOR that when the charge source is removed the input voltage decays below the UVLO threshold in a reasonable time. A 10F input capacitance charged up to the maximum OVLO threshold (6.0V - VOVLO) decays down to the minimum UVLO threshold (4.3V - VCHGINx_UVLO_MIN) within 300ms (tINSD). The input self-discharge is implemented by with a 30k resistor (RINSD) from CHGIN input to ground. System Self-Discharge with No Power To ensure a timely, complete, repeatable, and reliable reset behavior when the system has no power, the MAX77818 actively discharges the BATT and SYS nodes when the main battery is removed and VSYS is less than VSYSUVLO. As shown in Figure 5, the BATT and SYS discharge resistors are both 600. CHGIN VBUS BYP WCIN DM DP BST 4MHz BUCK CONTROLLER ID GND CHARGE CONTROLLER QHS CHGLX DRV_OUT REVERSE BOOST CONTROLLER QLS CHGPGND SYS SYSTEM IS UNDERVOLTAGE RPAR8 20m QBAT VSYSUVLO VMBDC MAIN-BATTERY IS DISCONNECTED 2x 600 SWITCHED BODY DIODE ID BATT DETBATB MAX77818 BAT_SP VMBAT BAT_SN RPAR7 20m RPAR1 20m RPAR2 20m RPAR4 20m RPAR5 20m ID RPAR6 20m Figure 5. Main Battery Charger High-Current Paths with Typical Parasitic Resistances and Self-Discharging Resistors www.maximintegrated.com Maxim Integrated 27 MAX77818 Dual Input, Power Path, 3A Switching Mode Charger with FG Charge States The MAX77818 utilizes several charging states to safely and quickly charge batteries as shown in Figure 6 and Figure 7. Figure 6 shows an exaggerated view of a Li+/Li-Poly battery progressing through the following charge states when there is not system load and the die and battery are close to room temperature: prequalification fast-charge top-off done. BATTERY VOLTAGE DONE CHG_DTLS[3:0]=0b0100 TOP-OFF CHG_DTLS[3:0]=0b0011 RESTART FAST CHARGE (CV) CHG_DTLS[3:0]=0b0010 DONE CHG_DTLS[3:0]=0b0100 TOP-OFF CHG_DTLS[3:0]=0b0011 FAST CHARGE (CV) CHG_DTLS[3:0]=0b0010 FAST CHARGE (CC) CHG_DTLS[3:0]=0b0001 LOW-BATTERY PREQUALIFICATION CHG_DTLS[3:0]=0b0000 STATES DEAD-BATTERY PREQUALIFICATION CHG_DTLS[3:0]=0b0000 NOT TO SCALE, VCHGIN = 5.0V, ISYS = 0A, TJ = 25C VBATREG VRSTRT NOTE1 VPQLB VPQDB 0V BATTERY CHARGE CURRENT TIME ICHG ISET IPQLB IPQDB ITO 0A CHARGER ENABLED TIME NOTE 1: A TYPICAL LI+/LI-POLY HAS AN INTERNAL BATTERY PACK PROTECTION CIRCUIT THAT WILL OPEN THE BATTERY CONNECTION WHEN THE BATTERY'S CELL VOLTAGE IS LOWER THAN A DEAD BATTERY THRESHOLD (VDB.FALLING~2.5V). TO GET THE PACK PROTECTION TO CLOSE AGAIN, THE CHARGER CHARGES THE BATTERY CAPACITOR WITH IPQDB UNTIL THE VOLTAGE EXCEEDS VPQDB. THEN THE CHARGER CHARGES THE BATTERY CAPACITOR WITH IPQLB. WHEN THE BATTERY CAPACITOR'S VOLTAGE EXCEEDS VDB.RISING~2.6V, THEN THE BATTERY PACK PROTECTION CIRCUIT CLOSES WHICH CONNECTS THE CELL TO THE CHARGER. VDB.FALLING AND VDB.RISING ARE NOT DETERMINED BY THE CHARGER - THEY ARE PROPERTIES OF THE BATTERY. Figure 6. Li+/Li-Poly Charge Profile www.maximintegrated.com Maxim Integrated 28 MAX77818 Dual Input, Power Path, 3A Switching Mode Charger with FG NO INPUT POWER OR CHARGER DISABLED CHG_DTLS = 0X08 CHG_OK = 1 ICHG = 0 CHG TIMER = 0 WD TIMER = 0 TJ > TSHDN (CHG TIMER = 0 WD TIMER = 0) TJ < TSHDN (CHG TIMER = SUSPEND WD TIMER = SUSPEND) THERMAL SHUTDOWN CHG_DTLS = 0X0A CHG_OK = 0 ICHG = 0 DEAD-BATTERY PREQUALIFICATION CHG_DTLS = 0x00 CHG_OK = 1 ICHG < = IPQDB WDTCLR[1:0] = 0B10 (WD TIMER = 0 AND RESUME CHG TIMER = RESUME) ANY STATE EXCEPT THERMAL SHUTDOWN CHGIN IS INVALID CHGIN IS VALID AND MODE PROGRAMMED FOR CHARGER ENABLED (CHG TIMER = RESUME WD TIMER = RESUME) WATCHDOG Suspend CHG_DTLS = 0x0B CHG_OK = 0 ICHG = 0 WD TIMER > TWD (CHG TIMER = SUSPEND, ONLY IF WDTEN = 1) MODE[3:0] PROGRAMED THE CHARGER TO BE OFF FROM: ANY PREQUAL STATE, ANY FAST CHARGE STATE, TOP-OFF, DONE OR TIMER FAULT. RETURNS TO: THE SAME STATE THAT IT CAME FROM. GT CH VMBATT > VPQDB (SOFT START) R> IME VMBATT < VPQDB (SOFT START) t PQ LOW-BATTERY PREQUALIFICATION CHG_DTLS = 0x00 CHG_OK = 1 If PQEN = 1, then ICHG < = IPQLB CHG TIME R>t PQ If PQEN = 0, then ICHG < = IFC VMBATT < VPQLB (CHG TIMER = 0) VMBATT > VPQLB (SOFT START, CHG TIMER = 0) VM (NO BATT < CH SOF (VBA G T T S TR IME TA EG VR R = RT, ST RE RT ) SU ME ) FAST CHARGE (CC) CHG_DTLS = 0x01 CHG_OK = 1 ICHG < = IFC VMBATT < VBATREG VMBATT < (VBATREG - VRSTRT) (NO SOFT START, CHG TIMER = RESUME) TIMER FAULT CHG_DTLS = 0x06 CHG_OK = 0 IBAT = 0 CHG TIMER > tFC VMBATT = VBATREG FOR 56ms FAST CHARGE (CV) CHG_DTLS = 0x02 CHG_OK = 1 ICHG < = IFC AND ICHG > ITO CHG TIMER > tFC IMBATT < ITO FOR tTERM (CHG TIMER = 0 AND SUSPEND) TOP OFF CHG_DTLS[3:0] = 0x03 CHG_OK = 1 ICHG < = IFC CHG TIMER > tTO DONE CHG_DTLS = 0x04 CHG_OK = 1 ICHG = 0 Figure 7. Charger State Diagram www.maximintegrated.com Maxim Integrated 29 MAX77818 No Input Power or Charger Disabled State From any state shown in Figure 7 except thermal shutdown, the no input power or charger disabled state is entered whenever the charger is programmed to be off or the charger input CHGIN is invalid. After being in this state for tSCIDG, a CHG_I interrupt is generated, CHG_OK is set and CHG_DTLS is set to 0x08 While in the no input power or charger disabled state, the charger current is 0mA, the watchdog and charge timers are forced to 0, and the power to the system is provided by either the battery or the adapter. When both battery and adapter power is available, the adapter provides primary power to the system and the battery contributes supplemental energy to the system if necessary. Dual Input, Power Path, 3A Switching Mode Charger with FG Therefore, a battery that stays in low battery prequalification for longer than tPQ may be experiencing a problem. Fast-Charge Constant Current State As shown in Figure 7, the fast-charge constant current (CC) state occurs when the main battery voltage is greater than the low battery prequalification threshold and less than the battery regulation threshold (VPQLB < VBATT < VBATREG). After being in the fast-charge CC state for tSCIDG, a CHG_I interrupt is generated, CHG_OK is set and CHG_DTLS = 0x01. In the fast-charge CC state, the current into the battery is less than or equal to IFC. Charge current can be less than IFC for any of the following reasons: To exit the no input power or charger disabled state, the charger input must be valid and the charger must be enabled. The charger input is in input current limit. Dead Battery Prequalificiation State The system load is consuming adapter current. Note that the system load always gets priority over the battery charge current. As shown in Figure 7, the dead battery prequalification state occurs when the main battery voltage is less than VPQDB. After being in this state for tSCIDG, a CHG_I interrupt is generated, CHG_OK is set and CHG_DTLS is set to 0x00. In the dead battery prequalification state charge current into the battery is IPQDB. Following events causes the state machine to exit this state: The main battery voltage rises above VPQDB and the charger enters the next state in the charging cycle: low battery prequalification. If the battery charger remains in this state for longer than tPQ, the charger state machine transitions to the timer fault state. If the watchdog timer is not serviced, the charger state machine transitions to the watchdog suspend state. Note that the dead battery prequalification state works with battery voltages down to 0V. The low 0V operation typically allows this battery charger to recover batteries that have an open internal pack protector. Typically a packs internal protection circuit opens if the battery has seen an over current, undervoltage, or overvoltage. When a battery with an open internal pack protector is used with this charger, the low battery prequalification mode current flows into the 0V battery. This current raises the pack's terminal voltage to the pointer where the internal pack protection switch closes. Note that a normal battery typically stays in the low battery prequalification state for several minutes or less. www.maximintegrated.com The charger input voltage is low. The charger is in thermal foldback. Following events causes the state machine to exit this state: When the main battery voltage rises above VBATREG, the charger enters the next state in the charging cycle: fast charge (CV). If the battery charger remains in this state for longer than tFC, the charger state machine transitions to the timer fault state. If the watchdog timer is not serviced, the charger state machine transitions to the watchdog suspend state. The battery charger dissipates the most power in the fast-charge constant current state. This power dissipation causes the internal die temperature to rise. If the die temperature exceeds TREG, IFC is reduced. Fast-Charge Constant Voltage State As shown in Figure 7, the fast-charge constant voltage (CV) state occurs when the battery voltage rises to VBATREG from the fast-charge CC state. After being in the fast-charge CV state for tSCIDG, a CHG_I interrupt is generated, CHG_OK is set and CHG_DTLS = 0x02. In the fast-charge CV state the battery charger maintains VBATREG across the battery and the charge current is less than or equal to IFC. As shown in Figure 6, charger current decreases exponentially in this state as the battery becomes fully charged. Maxim Integrated 30 MAX77818 The smart power selector control circuitry may reduce the charge current lower than the battery may otherwise consume for any of the following reasons: The charger input is in input current limit. The charger input voltage is low. The charger is in thermal foldback. The system load is consuming adapter current. Note that the system load always gets priority over the battery charge current. Following events causes the state machine to exit this state: When the charger current is below ITO for tterm, the charger enters the next state in the charging cycle: TOP OFF. If the battery charger remains in this state for longer than tFC, the charger state machine transitions to the timer fault state. If the watchdog timer is not serviced, the charger state machine transitions to the watchdog suspend state. Top-Off State As shown in Figure 7, the top-off state can only be entered from the fast-charge CV state when the charger current decreases below ITO for tTERM. After being in the top-off state for tSCIDG, a CHG_I interrupt is generated, CHG_OK is set and CHG_DTLS = 0x03. In the top-off state the battery charger tries to maintain VBATREG across the battery and typically the charge current is less than or equal to ITO. The smart power selector control circuitry can reduce the charge current lower than the battery is able to. Otherwise, consume for any of the following reasons: The charger input is in input current limit. The charger input voltage is low. The charger is in thermal foldback. The system load is consuming adapter current. Note that the system load always gets priority over the battery charge current. Following events causes the state machine to exit this state: After being in this state for the top-off time (tTO), the charger enters the next state in the charging cycle: DONE. If VBATT < VBATREG - VRSTRT, the charger goes back to the FAST CHARGE (CC) state. If the watchdog timer is not serviced, the charger state machine transitions to the watchdog suspend state. www.maximintegrated.com Dual Input, Power Path, 3A Switching Mode Charger with FG Done State As shown in Figure 7, the battery charger enters its done state after the charger has been in the top-off state for tTO. After being in this state for tSCIDG, a CHG_I interrupt is generated, CHG_OK is cleared and CHG_DTLS = 0x04. Following events causes the state machine to exit this state: If VBATT < VBATREG - VRSTRT, the charger goes back to the fast charge (CC) state. If the watchdog timer is not serviced, the charger state machine transitions to the watchdog suspend state. In the done state, the charge current into the battery (ICHG) is 0A. In the done state, the charger presents a very low load (IMBDN) to the battery. If the system load presented to the battery is low (<< 100A), then a typical system can remain in the done state for many days. If left in the done state long enough, the battery voltage decays below the restart threshold (VRSTRT) and the charger state machine transitions back into the fast-charge CV state. There is no soft-start (di/dt limiting) during the done to fast-charge state transition. Timer Fault State The battery charger provides both a charge timer and a watchdog timer to ensure safe charging. As shown in Figure 7, the charge timer prevents the battery from charging indefinitely. The time that the charger is allowed to remain in its each of its prequalification states is tPQ. The time that the charger is allowed to remain in the fast-charge CC and CV states is tFC which is programmable with FCHGTIME. Finally, the time that the charger is in the top-off state is tTO, which is programmable with TO_TIME. Upon entering the timer fault state a CHG_I interrupt is generated without a delay, CHG_OK is cleared and CHG_DTLS = 0x06. In the timer fault state the charger is off. The charger can exit the timer fault state by programming the charger to be off and then programming it to be on again through the MODE bits. Alternatively, the charger input can be removed and reinserted to exit the timer fault state. See the any state bubble in the upper right of Figure 7. Watchdog Timer The battery charger provides both a charge timer and a watchdog timer to ensure safe charging. As shown in Figure 7, the watchdog timer protects the battery from charging indefinitely in the event that the host hangs or otherwise cannot communicate correctly. The watchdog timer is disabled by default with WDTEN = 0. To use Maxim Integrated 31 MAX77818 Dual Input, Power Path, 3A Switching Mode Charger with FG the watchdog timer feature enable the feature by setting WDTEN. While enabled, the system controller must reset the watchdog timer within the timer period (tWD) for the charger to operate normally. Reset the watchdog timer by programming WDTCLR = 0x01. not experience this type of problem because BAT_SP and BAT_SN sense the battery voltage directly. To get the maximum benefit from these sense lines connect them as close as possible to the main battery connector. If the watchdog timer expires while the charger is in dead battery prequalification, low battery prequalification, fast charge CC or CV, top-off, done, or timer fault, the charging stops, a CHG_I interrupt is generated without a delay, CHG_OK is cleared, and CHG_DTLS indicates that the charger is off because the watchdog timer expired. Once the watchdog timer has expired, the charger can be restarted by programming WDTCLR = 0x01. The SYS node can be supported by the battery and/or the adapter through the DC-DC buck while the watchdog timer is expired. The DC-DC converter topology of the MAX77818 allows it to operate as a forward buck converter or as a reverse boost converter. The modes of the DC-DC converter are controlled with MODE. When MODE = 0x09 or 0x0A the DC-DC converter operates in reverse boost mode allowing it to source current to CHGIN. These two modes allow current to be sourced from CHGIN are commonly referred to as OTG modes (the term OTG is based off of the Universal Serial Bus's On the Go concept). Thermal Shutdown State As shown in Figure 7, the thermal shutdown state occurs when the battery charger is in any state and the junction temperature (TJ) exceeds the device's thermal shutdown threshold (TSHDN). When TJ is close to TSHDN, the charger has folded back the input current limit to 0A so the charger and inputs are effectively off. Upon entering this state, CHG_I interrupt is generated without a delay, CHG_OK is cleared, and CHG_DTLS = 0x0A. In the thermal shutdown state the charger is off and timers are suspended. The charger exits the temperature suspend state and returns to the state it came from once the die temperature has cooled. The timers resume once the charger exits this state. Main Battery Differential Voltage Sense As shown in Figure 2, BAT_SP and BAT_SN are differential remote sense lines for the main battery. To improve accuracy and decrease charging times, the battery charger voltage sense is based on the differential voltage between BAT_SP and BAT_SN. Figure 5 shows the high-current paths of the battery charger along with some example parasitic resistances. A Maxim battery charger without the remote-sensing function would typically measure the battery voltage between BATT and GND. In the case Figure 5 with a charge current of 1A measuring from BATT to GND leads to a VBATT that is 40mV higher than the real voltage because of RPAR1 and RPAR7 (ICHG x (RPAR1 + RPQR7) = 1A x 40m = 40mV). Since the charger thinks the battery voltage is higher than it actually is, it will enter its fast-charge CV state sooner and the effective charge time may be extended by 10 minutes (based on real lab measurements). This charger with differential remote sensing does www.maximintegrated.com OTG Mode When MODE = 0x09 or 0x0A the DC-DC converter operates in reverse boost mode and regulates VBYP to VBYP.OTG (5.1V typ) and the switch from BYP to CHGIN is closed. The current through the BYP to CHGIN switch is limited to the value programmed by OTG_ILIM. The two OTG_ILIM options allow for supplying 100mA or 500mA to an external load.. When the OTG mode is selected, the unipolar CHGIN transfer function measures current going out of CHGIN. When OTG mode is not selected, the unipolar CHGIN transfer function measures current going into CHGIN. If the external OTG load at CHGIN exceeds ICHGIN.OTG. ILIM, then a BYP_I interrupt is generated, BYP_OK = 0, and BYP_DTLS = 0bxxx1. In response to an overload at CHGIN during OTG mode operation, the BYP to CHGIN switch is latched off. The BYP to CHGIN switch will automatically try to retry in ~300ms. If the overload at CHGIN persists, then the switch will toggle on and off with ~30ms on and ~300ms off. Main Battery Overcurrent Protection During System Power-Up The main battery overcurrent protection during system power-up feature limits the main battery to system current to ISYSPU as long as VSYS is less than VSYSPU. This feature limits the surge current that typically flows from the main battery to the device's low-impedance system bypass capacitors during a system power-up. System power-up is anytime that energy from the battery is supplied to SYS when VSYS < VSYSPU. This system power-up condition typically occurs when a battery is hotinserted into an otherwise unpowered device. Similarly, the system power-up condition could occur when the DISIBS bit is driven low. Maxim Integrated 32 MAX77818 When system power-up occurs due to hot insertion into an otherwise unpowered device, a small delay of (tSYSPU) is required in order for this feature's control circuits to activate. A current spike over ISYSPU can occur during this time. Main Battery Overcurrent Protection Due to Fault The MAX77818 protects itself, the battery, and the system from potential damage due to excessive battery discharge current. Excessive battery discharge current may occur in a smartphone for several reasons such as exposure to moisture, a software problem, an IC failure, a component failure, or a mechanical failure that causes a short circuit. The main battery overcurrent protection feature is enabled with B2SOVRC; disabling this feature reduces the main battery current consumption by IMBOVRC. When the main battery (BATT) to system (SYS) discharge current (IBATT) exceeds the programmed overcurrent threshold for at least tMBOVRC, a BAT_I interrupt is generated, BAT_OK is cleared, and BAT_DTLS reports and overcurrent condition. Typically when the system's processor detects this overcurrent interrupt it executes a housekeeping routine that tries to mitigate the overcurrent situation. If the processor cannot correct the overcurrent, then it can disable the BATT to SYS discharge path (B2S switch) by driving DISIBS bit to a logic high. Dual Input, Power Path, 3A Switching Mode Charger with FG To exit from this state, plug in a valid input charger, then SYS is powered up and the system wakes up. The MAX77818 is powered from BATT and CHGIN and the charger buck is switching and DISIBS bit is set. The DISIBIS bit is ignored. Thermal Management The MAX77818 charger uses several thermal management techniques to prevent excessive battery and die temperatures. Thermal Monitor The user can monitor thermistor temperature using the fuel gauge and adjust the charger voltage/current as needed. Thermal Foldback SYS collapses and is allowed to go to 0V. Thermal foldback maximizes the battery charge current while regulating the MAX77818 junction temperature. As shown in Figure 8, when the die temperature exceeds the value programmed by REGTEMP (TJREG), a thermal limiting circuit reduces the battery charger's target current by 105mA/C (ATJREG). The target charge current reduction is achieved with an analog control loop (i.e., not a digital reduction in the input current). When the thermal foldback loop changes state a CHG_I interrupt is generated and the system's microprocessor may want to read the status of the thermal regulation loop through the TREG status bit. Note that the thermal foldback loop being active is not considered to be abnormal operation and the thermal foldback loop status does not affect the CHG_OK bit (only information contained within CHG_DTLS affects CHG_OK). DISIBS holds state. Analog Low-Noise Power Input (AVL) and PVL To exit from this state, plug in a valid input charger, then SYS is powered up, and the system wakes up. As shown in Figure 2, AVL is a regulated output from BYPC node. AVL is the power input for the MAX77818 charger's analog circuitry. PVL has a 12.5 resistor internal to the MAX77818 and a 10F ceramic capacitor external bypass capacitor to isolate noises from AVL. There are different scenarios of how the MAX77818 responds to setting the DISIBS bit high depending on the available power source and the state of the charger. The MAX77818 is only powered from BATT and DISIBS bit is set. The MAX77818 is powered from BATT and CHGIN, and the charger buck is not switching and DISIBS bit is set. www.maximintegrated.com Maxim Integrated 33 MAX77818 Dual Input, Power Path, 3A Switching Mode Charger with FG DRAWN TO SCALE, VCHGIN = 5.0V, VSYS = 0A, CHGINA_ILIM IS SET FOR MAXIMUM 3.0A BATTERY CHARGER OPERATION IN THERMAL REGULATION GENERATES A CHG_I INTERRUPT BIT AND SETS THE TREG STATUS BIT AJTREG = -105mA/C IFC = 2.0A CURRENT (A) 2.0A IFC = 3.0A 1.0A IFC = 1.0A 0.0A TJREG TJREG +9.5C TJREG +19C TJREG +28.6C JUNCTION TEMPERATURE (C) Figure 8. Charge Currents vs. Junction Temperature www.maximintegrated.com Maxim Integrated 34 MAX77818 Dual Input, Power Path, 3A Switching Mode Charger with FG NO CHARGE-BUCK QCHGIN = ON or QWCIN = ON QBAT = OFF (MODE = 0x0C) VBYP = VCHGIN/WCIN - IxR CHGIN OR WCIN VALID CHGIN AND WCIN INVALID NO INPUT POWER BATTERY REMOVED, FAULT BATTERY REMOVED, FAULT BATTERY DETECT, FAULT REMOVED CHGIN OR WCIN PRESENCE END OTG START OTG CHARGE-BUCK CHGIN=ON or WCIN=ON QBAT=ON (MODE=0x0D) VBYP = VCHGIN/WCIN - IxR BATTERY DETECT, FAULT REMOVED BATTERY ONLY CHGIN = OFF WCIN = OFF QBAT = ON (MODE = 0x00) VBYP = VCHGIN/WCIN - IxR START BOOST/OTG VSYS = VBAT - IxR NO CHGIN AND NO WCIN END BOOST/OTG BATTERY-BOOST CHGIN = OFF WCIN = OFF QBAT = ON (MODE = 0x08) VBYP = VBYPSET BOTH VIN < VIN_UVLO_FALL BOTH IIN < IIN_low (50mA) BOTH VIN > VIN_UVLO_RISE VSYS = max(VBAT + V, VSYSMIN) VSYS = VBAT - IxR END OTG END OTG NO CHARGE-BUCK (OTG) CHGIN = ON WCIN = ON QBAT = OFF (MODE = 0x0E) VBYP = VCHGIN/WCIN - IxR VSYS = VEOC BATTERY DETECT BATTERY REMOVED START OTG START OTG (MODE B) CHARGE-BUCK (OTG) CHGIN = ON WCIN = ON QBAT = ON (MODE = 0x0F) VBYP = VCHGIN/WCIN - IxR VWCIN < VIN_UVLO_FALL IWCIN < IWCIN_low (50mA) VWCIN > VIN_UVLO_RISE VSYS = VBAT - IxR BATTERY-BOOST (OTG) CHGIN = ON WCIN = OFF QBAT = ON (MODE = 0x0A) VBYP = VBYP_OTG VSYS = max(VBAT + V, VSYSMIN) IOTG > ILIM.OTG IOTG > ILIM.OTG IOTG < ILIM.OTG OTG FAULT (OCP) OTG Interrupt 0xB0[7] = 1 IOTG < ILIM.OTG Figure 9: Power State Diagram www.maximintegrated.com Maxim Integrated 35 MAX77818 Dual Input, Power Path, 3A Switching Mode Charger with FG Power States The MAX77818 transitions between power states as input/battery and load conditions dictate; see Figure 9. The MAX77818 provides seven (7) power states and one (1) no power state. Under power-limited conditions, the power path feature maintains SYS and USB-OTG loads at the expense of battery charge current. In addition, the battery supplements the input power when required. As shown, transitions between power states are initiated by detection/removal of valid power sources, OTG events, and under-voltage conditions. Details of the BYP and SYS voltages are provided for each state. No Input Power, MODE = undefined: No input adapter or battery is detected. The charger and system is off. Battery is disconnected and charger is off. Battery Only, MODE = 0x00: Adapter and wireless charger are invalid, outside the input voltage operating range (QCHGIN = off, QWCIN = off). Battery is connected to power the SYS load (QBAT = on), and boost is ready to power OTG (Boost=standby), see Figure 10. Battery Only. Battery Boost, MODE = 0x08: Adapter and Wireless inputs are invalid, outside the input voltage operating range (QCHGIN = off, QWCIN = off). Battery is connected to power the SYS load (QBAT = on), and charger is operating in Boost mode (Boost = on). See Figure 11. QCHGIN OPEN CHGIN BYP QHS OPEN WCIN CHGLX QLS QWCIN MAX77818 QBAT SYS V-SYS = V- BATT- I- BATT x R(QBAT) BYP V-BYP = V- BYPSET REVERSE BLOCKING BATT I-BATT Figure 10. Battery-Only QCHGIN OPEN CHGIN QHS OPEN WCIN CHGLX QLS QWCIN MAX77818 SYS QBAT V-SYS = V- BATT- I- BATT x R(QBAT) REVERSE BLOCKING I-BATT BATT Figure 11. Battery-Boost www.maximintegrated.com Maxim Integrated 36 MAX77818 Dual Input, Power Path, 3A Switching Mode Charger with FG Battery Boost Battery Boost (OTG), MODE = 0x0A: Wireless input is turned off (QWCIN = off) and OTG is active (QCHGIN = on). Battery is connected to support SYS and OTG loads (QBAT = on), and charger is operating in boost mode (boost = on). See Figure 12. I-OTG V- OTG = 5.1V- I- OTG x R(QCHGIN) OPEN No Charge Buck, MODE = 0x0C: Adapter or wireless charger are detected, within the input voltage operating range (QCHGIN = on or QWCIN = on). Battery is disconnected (QBAT = off), and charger is operating in buck mode powering the SYS node. See Figure 13. QCHGIN CHGIN V-BYP = V- BYPSET BYP QHS WCIN CHGLX QLS QWCIN MAX77818 V-SYS = V- BATT- I- BATT x R(QBAT) SYS QBAT REVERSE BLOCKING I-BATT BATT Figure 12. Battery Boost (OTG) QCHGIN ADP CHGIN BYP QHS OR WC WCIN V-BYP = V- CHGIN- I- QCHGIN x R(QCHGIN) OR V- BYP = V- WCIN- I- QWCIN x R(QWCIN) CHGLX QLS QWCIN MAX77818 SYS QBAT V-SYS = V- BATT REVERSE BLOCKING BATT V- BATT = CHG_CV_PRM Figure 13. No Charge Buck www.maximintegrated.com Maxim Integrated 37 MAX77818 Dual Input, Power Path, 3A Switching Mode Charger with FG Charge Buck, MODE = 0x0D: Adapter or wireless charger are detected, within the input voltage operating range (QCHGIN = on or QWCIN = on). Battery is connected in charge mode (QBAT = on), and charger is operating in buck mode. See Figure 14. No Change Buck (OTG), MODE = 0x0E: Wireless charger is detected within the input voltage operating range (QWCIN = on) and OTG is active (QCHGIN = of). Battery is connected in charge mode (QBAT = on), and charger is operating in buck mode. See Figure 15. QCHGIN ADP CHGIN QHS OR WC V-BYP = V- CHGIN- I- QCHGIN x R(QCHGIN) OR V- BYP = V- WCIN- I- QWCIN x R(QWCIN) BYP WCIN CHGLX QLS QWCIN MAX77818 SYS QBAT V-SYS = MAX(MINVSYS, V-BATT+?) REVERSE BLOCKING I- BATT *MAY BE 0A(MAINTAIN CHARGE) BATT Figure 14. Charge Buck I-OTG V- OTG = V - BYP- IOTG x R(QCHGIN) V- WC > V- WCIN. UVLO QCHGIN CHGIN BYP QHS I- WCIN WCIN V-BYP = V- WCIN- [I- WC- I-OTG] x R(QCHGIN) CHGLX QLS QWCIN MAX77818 SYS QBAT V-SYS = MAX(MINVSYS, V-BATT+?) REVERSE BLOCKING I- BATT BATT Figure 15. No Charge Buck (OTG) www.maximintegrated.com Maxim Integrated 38 MAX77818 Dual Input, Power Path, 3A Switching Mode Charger with FG Charge Buck (OTG), MODE = 0x0F: Wireless charger is detected within the input voltage operating range (QWCIN = on) and OTG is active (QCHGIN = on). Battery is connected in charge mode (QBAT = on), and charger is operating in buck mode powering the SYS node. See Figure 16. error in the coulomb counter, while providing better shortterm accuracy than any purely voltage-based fuel gauge. Additionally, the ModelGauge m5 algorithm does not suffer from abrupt corrections that normally occur in coulombcounter algorithms, since tiny continual corrections are distributed over time. Safeout LDOs The device automatically compensates for aging, temperature, and discharge rate and provides accurate state of charge (SOC) in mAh or %, as well as time-to-empty over a wide range of operating conditions. The device provides two methods for reporting the age of the battery: reduction in capacity and cycle odometer. Safeout with Input Overvoltage Protection The safeout LDOs are linear regulators that provides an output voltage of 3.3V, 4.85V, 4.9V, or 4.95V and can be used to supply low voltage rated USB systems. The SAFEOUT1 linear regulator turns on when CHGIN CHGIN_UVLO and ENSAFEOUT_ = logic-high regardless of charger enable or DETBATB. SAFEOUT_ is disabled when CHGIN is greater than the overvoltage threshold (13.7V typ). The safeout LDOs integrate highvoltage MOSFETs to provide 14V protection at their inputs, which are internally connected to the BYP. SAFEOUT1 is default ON at 4.9V. SAFEOUT2 is default off. Fuel Gauge The MAX77818 incorporates the ModelGauge m5 algorithm that combines the excellent short-term accuracy and linearity of a coulomb counter with the excellent long-term stability of a voltage-based fuel gauge, along with temperature compensation to provide industry-leading fuel-gauge accuracy. ModelGauge m5 cancels offset accumulation I-OTG V- OTG = V - BYP- IOTG x R(QCHGIN) V- WC > V- WCIN. UVLO The device provides precision measurements of current, voltage, and temperature. Temperature of the battery pack is measured using an external thermistor supported by ratiometric measurements on an auxiliary input. A 2-wire (I2C) interface provides access to data and control registers. Features Accurate battery capacity and time-to-empty readings Estimation * Temperature, age, and rate Compensated * Does not require empty, full, or idle states to Maintain accuracy Precision measurement system * No calibration required QCHGIN CHGIN BYP QHS I- WCIN WCIN V-BYP = V- WCIN- [I- WC- I-OTG] x R(QCHGIN) CHGLX QLS QWCIN MAX77818 SYS QBAT V-SYS = MAX(MINVSYS, V-BATT+?) REVERSE BLOCKING BATT I- BATT Figure 16. Charge-Buck (OTG) www.maximintegrated.com Maxim Integrated 39 MAX77818 Dual Input, Power Path, 3A Switching Mode Charger with FG ModelGauge m5 algorithm * Long-term influence by voltage fuel gauge Slave Addresses Cancels coulomb-counter drift * Short-term influence by coulomb counter Clogic, GTEST and Safeout LDOs: 0xCCh/0xCDh Provides excellent linearity * Adapts to cell characteristics External temperature-measurement network * Actively switched thermistor resistive divider * Reduces current consumption Low quiescent current * 25A active, < 0.5A shutdown Charger : 0xD2/D3h Fuel Gauge: 0x6C/0x6D. See the Fuel Gauge I2C Protocol for details in Fuel Gauge section. I2C Bit Transfer One data bit is transferred for each clock pulse. The data on SDA must remain stable during the high portion of the clock pulse as changes in data during this time are interpreted as a control signal. I2C Start and Stop Conditions Alert Indicator for SOC, voltage, temperature, and battery removal/insertion events At rate estimation of remaining capacity I2C Interface Both SDA and SCL remain High when the bus is not busy. A high-to-low transition of SDA, while SCL is high is defined as the start (S) condition. A low-to-high transition of SDA while SCL is high is defined as the stop (P) condition. The MAX77818 acts as a slave transmitter/receiver. The MAX77818 has the following slave address. SDA I2C DISABLED IC DISABLED IC ENABLED I2C ENABLED I2C ADDRESS DATA LINE STABLE; DATA VALID STOP CONDITION ANY STATE EXCEPT DISABLED CHARGER (0xD2/D3h) SCL CHANGE OF DATA ALLOWED MBBC821 Figure 18. I2C Bit Transfer FUEL GAUGE (0x6C/0x6Dh) SDA SDA IC TOP (CC/CDh) SAFEOUT LDOs Figure 17. I2C Slave Address Structure www.maximintegrated.com SCL S P START CONDITION STOP CONDITION SCL MBBC821 Figure 19. I2C Start and Stop Maxim Integrated 40 MAX77818 Dual Input, Power Path, 3A Switching Mode Charger with FG I2C System Configuration A device on the I2C bus that generates a message is called a transmitter and a device that receives the message is a receiver. The device that controls the message is the master. The devices that are controlled by the master are called slaves. I2C Acknowledge The number of data bytes between the start and stop conditions for the transmitter and receiver are unlimited. Each 8-bit byte is followed by an acknowledge bit. The acknowledge bit is a high-level signal put on SDA by the transmitter during the time the master generates an extra acknowledge-related clock pulse. A slave receiver that is addressed must generate an acknowledge after each byte it receives. Also, a master receiver must generate an acknowledge after each byte it receives that has been clocked out of the slave transmitter. The device that acknowledges must pull down the SDA line during the acknowledge clock pulse, so that the SDA line is stable low during the high period of the acknowledge clock pulse (set-up and hold times must also be met). A master receiver must signal an end of data to the transmitter by not generating an acknowledge on the last byte that has been clocked out of the slave. In this case, the transmitter must leave SDA high to enable the master to generate a stop condition. SDA SCL MASTER TRANSMITTER / RECEIVER SLAVE TRANSMITTER / RECEIVER SLAVE RECEIVER MASTER TRANSMITTER / RECEIVER MASTER TRANSMITTER Figure 20. I2C System Configuration DATA OUTPUT BY TRANSMITTER NOT ACKNOWLEDGE DATA OUTPUT BY RECEIVER ACKNOWLEDGE SCL FROM MASTER 1 2 8 9 S START CONDITION MBBC602 CLOCK PULSE FOR ACKNOWLEDGE Figure 21. I2C Knowledge www.maximintegrated.com Maxim Integrated 41 MAX77818 Dual Input, Power Path, 3A Switching Mode Charger with FG Master Transmits (Write Mode) When master writes to slave, use the following format: B7 S B0 SLAVE ADDRESS 0 B7 AS B0 REGISTER ADDRESS B7 AS B0 DATA AS P n BYTES R/W AUTO INCREMENT REGISTER ADDRESS S: I2C START CONDITION BY MASTER AS: ACKNOWLEDGEMENT BY SLAVE P: I2C STOP CONDITION BY MASTER Master Reads After Setting Register Address (Write Register Address and Read Data) When reading a specific register, use the following format: B7 S B0 SLAVE ADDRESS B7 0 AS B0 REGISTER ADDRESS B7 AS S B7 B0 SLAVE ADDRESS R/W 1 AS DATA AM n BYTES R/W S: I2C START CONDITION BY MASTER AS: ACKNOWLEDGEMENT BY SLAVE P: I2C STOP CONDITION BY MASTER AM: ACKNOWLEDGEMENT BY MASTER B0 AUTO INCREMENT REGISTER ADDRESS DATA 1 P LAST BYTE NO ACKNOWLEDGEMENT FROM MASTER Master Reads Register Data Without Setting Register Address (Read Mode) When reading registers from the first address, use the following format: B7 S B0 SLAVE ADDRESS 1 R/W S: I2C START CONDITION BY MASTER AS: ACKNOWLEDGEMENT BY SLAVE P: I2C STOP CONDITION BY MASTER www.maximintegrated.com B7 AS B0 DATA B7 AM n BYTES AUTO INCREMENT REGISTER ADDRESS B0 DATA 1 P n BYTES AUTO INCREMENT REGISTER ADDRESS NO ACKNOWLEDGEMENT FROM MASTER Maxim Integrated 42 MAX77818 Dual Input, Power Path, 3A Switching Mode Charger with FG I2C Register Map and Detail Descriptions Register Reset Conditions in R column Type S: Registers are reset each time when SYS < SYS POR (~1.55V) Type O: Registers are reset each time when SYS < SYS UVLO (2.55V max) or SYS > SYS OVLO or Die temp > 165 (or MAX77818 transitions from on to off state) Top Level I2C Registers The MAX77818 acts as a slave transmitter/receiver. The slave address of the MAX77818 top is 0xCCh/0xCDh (OTP option for 0xDC/0xDDh). The least significant bit is the read/write indicator. The MAX77818's tope level has the following registers: 0x20: PMIC ID Register NAME FUNCTION ADDR PMICID PMIC ID 0x20 BIT MODE NAME RESET 3:0 R ID 0011 7:4 R ID 0010 TYPE RESET O 0x23 DESCRIPTION ID of MAX77818 0x21: PMIC Version/Rev Register NAME FUNCTION ADDR PMICREV PMIC revision 0x21 NAME RESET DESCRIPTION -- Pass 0b000 = pass 1 0b001 = pass 2 0b010 = pass 3 -- Version 0b00000 = zmo 0b00001 = ymo ... Null Trim Version 0b10000 = tmo 0b10001 = umo BIT 2:0 7:3 MODE R R www.maximintegrated.com REV VERSION TYPE RESET O 0x80 Maxim Integrated 43 MAX77818 Dual Input, Power Path, 3A Switching Mode Charger with FG 0x22: Interrupt Source BIT NAME FUNCTION ADDR INTSRC Interrupt source 0x22 NAME RESET MODE TYPE RESET S 0x00 DESCRIPTION 0 R CHGR_INT 0 0: No charger interrupt. 1: Charger interrupt is detected. 1 R FG_INT 0 0 = No interrupt pending from FG block. 1 = interrupt from FG block is detected . 2 R SYS_INT 0 0: No SYS INT 1: SYS interrupt is detected. 3 R RSVD 0 Reserved 4 R RSVD 0 Reserved 5 R RSVD 0 Reserved 6 R RSVD 0 Reserved 7 R RSVD 0 Reserved 0x23: Interrupt Source Mask NAME FUNCTION ADDR INTSRCMASK Interrupt source mask 0x23 NAME RESET TYPE RESET S 0xFF BIT MODE 0 R/W CHGR_INT_MASK 1 1: Charger interrupt is masked. 1 R/W FG_INT_MASK 1 1: FG interrupt is masked. 2 R/W SYS_INT_MASK 1 1: SYS interrupt is masked. 3 R/W RSVD 1 Reserved 4 R/W RSVD 1 Reserved 5 R/W RSVD 1 Reserved 6 R/W RSVD 1 Reserved 7 R/W RSVD 1 Reserved www.maximintegrated.com DESCRIPTION Maxim Integrated 44 MAX77818 Dual Input, Power Path, 3A Switching Mode Charger with FG 0x24: SYSTEM Interrupt NAME FUNCTION ADDR SYSINTSRC SYS interrupt source 0x24 TYPE RESET S 0x00 BIT MODE NAME RESET DESCRIPTION 0 R SYSUVLO_INT 0 0: No SYSUVLO INT. 1: SYSUVLO interrupt is detected (falling). 1 R SYSOVLO_INT 0 0: No SYSOVLO interrupt. 1: SYSOVLO interrupt is detected (rising and falling). 2 R TSHDN_INT 3 R RSVD 0 Reserved 4 R RSVD 0 Reserved 5 R RSVD 0 Reserved 6 R RSVD 0 Reserved 7 R TM_INT 0 0: Test mode interrupt is not set. 1: Test mode interrupt is set. 0: No TSHDN interrupt. 1: TSHDN interrupt is detected. 0x26: SYSTEM Interrupt Source Mask NAME FUNCTION ADDR SYSINTMASK System interrupt mask 0x26 BIT MODE NAME RESET TYPE RESET S 0xFF DESCRIPTION 0 R/W SYSUVLO_INT_MASK 1 1: SYSUVLO interrupt is masked. 1 R/W SYSOVLO_INT_MASK 1 1: SYSUVLO interrupt is masked. 2 R/W TSHDN_INT_MASK 1 1: Thermal shutdown interrupt is masked. 3 R/W RSVD 1 Reserved 4 R/W RSVD 1 Reserved 5 R/W RSVD 1 Reserved 6 R/W RSVD 1 Reserved 7 R/W TM_INT_MASK 0 1: INT test mode interrupt is masked. www.maximintegrated.com Maxim Integrated 45 MAX77818 Dual Input, Power Path, 3A Switching Mode Charger with FG 0xC6: SAFEOUT LDO Control NAME FUNCTION ADDR TYPE RESET SAFEOUTCTRL SAFEOUT linear regulator control 0xC6 O 0x75 NAME RESET BIT 1:0 MODE R/W SAFEOUT1[1:0] DESCRIPTION 01 SAFEOUT1 output voltage 00: 4.85V 01: 4.90V (default) 10: 4.95V 11: 3.3V. 3:2 R/W SAFEOUT2[3:2] 01 SAFEOUT2 output voltage 00: 4.85V 01: 4.90V (default) 10: 4.95V 11: 3.3V 4 R/W ACTDISSAFEO1 1 0: No active discharge 1: Active discharge 5 R/W ACTDISSAFEO2 1 0: No active discharge 1: Active discharge 6 R/W ENSAFEOUT1 1 SAFEOUTLDO1 enable bit 0: Disable SAFEOUT1. 1: Enable SAFEOUT1. 7 R/W ENSAFEOUT2 0 SAFEOUTLDO2 enable bit 0: Disable SAFEOUT2. 1: Enable SAFEOUT2. Charger I2C Registers The MAX77818's charger has convenient default register settings and a complete charger state machine that allow it to be used with minimal software interaction. Software interaction with the register map enhances the charger by allowing a high degree of configurability. An easy-tonavigate interrupt structure and in-depth status reporting allows software to quickly track the changes in the charger's status. Register Protection The CHG_CNFG_01, CHG_CNFG_02, CHG_CNFG_03, CHG_CNFG_04, CHG_CNFG_05, and CHG_CNFG07 registers contain settings for static parameters that are associated with a particular system and battery. These static settings are typically set once each time the system's microprocessor runs its boot-up initialization code; then they are not changed again until the microprocessor re-boots. CHGPROT allows for blocking the "write" access to these static settings to protect them from being www.maximintegrated.com changed unintentionally. This protection is particularly useful for critical parameters such as the battery charge current CHG_CC and the battery charge voltage CHG_ CV_PRM Determine the following registers bit settings by considering the characteristics of the battery. Maxim recommends that CHG_CC be set to the maximum acceptable charge rate for your battery - there is typically no need to actively adjust the CHG_CC setting based on the capabilities of the source at CHGIN, system load, or thermal limitations of the PCB; the smart power selector intelligently manages all these parameters to optimize the power distribution. Charger Restart Threshold CHG_RSTRT Fast-Charge Timer (tFC) FCHGTIME Fast-Charge Current CHG_CC Top-Off Time TO_TIME Top-Off Current TO_ITH Battery Regulation Voltage CHG_CV_PRM Maxim Integrated 46 MAX77818 Dual Input, Power Path, 3A Switching Mode Charger with FG Determine the following register bit settings by considering the characteristics of the system: Low Battery Prequalification Enable PQEN Minimum System Regulation Voltage MINVSYS Junction Temperature Thermal Regulation Loop Setpoint REGTEMP Interrupt, Mask, OK, and Detail Registers The battery charger section of the MAX77818 provides detailed interrupt generation and status for the following subblocks: Charger Input State changes on any subblock report interrupts through the CHG_INT register. Interrupt sources are masked from affecting the hardware interrupt pin when bits in the CHG_ INT_MASK register are set. The CHG_INT_OK register provides a single-bit status indication of whether the interrupt generating sub-block is okay or not. The full status of interrupt generating subblock is provided in the CHG_ DETAILS_00, CHG_DETAILS_01, CHG_DETAILS_02, and CHG_DETAILS_03 registers. Note that CHG_INT, CHG_INT_MASK and CHG_INT_OK use the same bit position for each interrupt generating block to simplify software development. Interrupt bits are automatically cleared upon reading a given interrupt register. When all pending CHG_INT interrupts are cleared, the top level interrupt bit deasserts. Charger State Machine Battery Bypass Node CHG_INT Register Bit Description (0xB0) NAME FUNCTION ADDR CHG_INT Charger interrupt 0xB0 TYPE RESET O 0x00 BIT MODE NAME RESET 0 R/C BYP_I 0 Bypass Node Interrupt 0 = The BYP_OK bit has not changed since the last time this bit was read. 1 = The BYP_OK bit has changed since the last time this bit was read. 1 R/C RSVD 0 Reserved 2 R/C BATP_I 0 Battery Presence Interrupt. 0 = The BATP_OK bit has not changed since the last time this bit was read. 1 = The BATP_OK bit has changed since the last time this bit was read.s 3 R/C BAT_I 0 Battery Interrupt 0 = The BAT_OK bit has not changed since the last time this bit was read. 1 = The BAT_OK bit has changed since the last time this bit was read. 4 R/C CHG_I 0 Charger Interrupt 0 = The CHG_OK bit has not changed since the last time this bit was read. 1 = The CHG_OK bit has changed since the last time this bit was read. 5 R/C WCIN_I 0 WCIN Interrupt. 0 = The WCIN_OK bit has not changed since the last time this bit was read. 1 = The WCIN_OK bit has changed since the last time this bit was read. 6 R/C CHGIN_I 0 CHGIN Interrupt. 0 = The CHGIN_OK bit has not changed since the last time this bit was read. 1 = The CHGIN_OK bit has changed since the last time this bit was read. 7 R/C AICL_I 0 AICL interrupt 0=The AICL_OK bit has not changed since the last time this bit was read. 1=The AICL_OK bit has changed since the last time this bit was read. www.maximintegrated.com DESCRIPTION Maxim Integrated 47 MAX77818 Dual Input, Power Path, 3A Switching Mode Charger with FG CHG_INT_MASK Register Bit Description (0xB1) NAME FUNCTION ADDR CHG_INT_MASK Charger interrupt mask 0xB1 TYPE RESET O 0xFF BIT MODE NAME RESET 0 R/W BYP_M 1 Bypass Interrupt Mask 0 = Unmasked 1 = Masked 1 R/W RSVD 1 Reserved 2 R/W BATP_M 1 Battery Presence Interrupt Mask 0 = Unmasked 1 = Masked 3 R/W BAT_M 1 Battery Interrupt Mask 0 = Unmasked 1 = Masked 4 R/W CHG_M 1 Charger Interrupt Mask 0 = Unmasked 1 = Masked 5 R/W WCIN_M 1 WCIN Interrupt Mask 0 = Unmasked 1 = Masked 6 R/W CHGIN_M 1 CHGIN Interrupt Mask 0 = Unmasked 1 = Masked 7 R/W AICL_M 1 AICL Interrupt Mask 0 = Unmasked 1 = Masked www.maximintegrated.com DESCRIPTION Maxim Integrated 48 MAX77818 Dual Input, Power Path, 3A Switching Mode Charger with FG CHG_INT_OK Register Bit Description (0xB2) NAME FUNCTION ADDR CHG_INT_OK Charger status 0xB2 NAME RESET BIT MODE TYPE RESET O 0x00 DESCRIPTION 0 R BYP_OK 0 Single-Bit Bypass Status Indicator. See BYP_DTLS for more information. 0 = Something powered by the bypass node has hit current limit. i.e., BYP_ DTLS 0x00. 1 = The bypass node is okay. i.e., BYP_DTLS = 0x00. 1 R RSVD 0 Reserved 2 R BATP_OK 0 BAT present status indicator. 0 = Main Battery is not present 1 = Main Battery is present. 0 Single-Bit Battery Status Indicator. See BAT_DTLS for more information. 0 = The battery has an issue or the charger has been suspended, i.e., BAT_ DTLS 0x03 or 0x04 1 = The battery is okay. i.e., BAT_DTLS = 0x03 or 0x04 0 Single-Bit Charger Status Indicator. See CHG_DTLS for more information. 0 = The charger has suspended charging or TREG = 1 i.e., CHG_DTLS 0x00 or 0x01 or 0x02 or 0x03 or 0x05 or 0x08 1 = The charger is okay or the charger is off i.e., CHG_DTLS = 0x00 or 0x01 or 0x02 or 0x03 or 0x05 or 0x08 0 Single-Bit WCIN Input Status Indicator. See WCIN_DTLS for more information. 0 = The WCIN input is invalid. i.e., WCIN_DTLS 0x03. 1 = The WCIN input is valid. i.e., WCIN_DTLS = 0x03. 3 4 5 R BAT_OK R CHG_OK R WCIN_OK 6 R CHGIN_OK 0 Single-Bit CHGIN Input Status Indicator. See CHGIN_DTLS for more information. 0 = The CHGIN input is invalid. i.e., CHGIN_DTLS 0x03. 1 = The CHGIN input is valid. i.e., CHGIN_DTLS = 0x03. 7 R AICL_OK 0 AICL_OK 0 = AICL mode 1 = Not in AICL mode www.maximintegrated.com Maxim Integrated 49 MAX77818 Dual Input, Power Path, 3A Switching Mode Charger with FG CHG_DETAILS_00 Register Bit Description (0xB3) NAME FUNCTION ADDR CHG_DTLS_00 Charger details 00 0xB3 TYPE RESET O 0x00 BIT MODE NAME RESET 0 R BATP_DTLS 0 Battery Detection 0 = Battery presence 1 = No battery presence 2:1 R RSVD 00 Reserved 00 WCIN Details 0x00 = VWCIN is invalid. VWCIN < VWCIN_UVLO 0x01 = VWCIN is invalid. VWCIN < VMBAT + VWCIN2SYS and VWCIN > VWCIN_UVLO 0 x 02 = VWCIN is invalid. VWCIN>VWCIN_OVLO 0 x 03 = VWCIN is valid. VWCIN > VWCIN_UVLO, VWCIN > VMBAT + VWCIN2SYS, VWCIN < VWCIN_OVLO 4:3 R WCIN_DTLS DESCRIPTION 6:5 R CHGIN_DTLS 00 CHGIN Details 0x00 = VBUS is invalid. VCHGIN < VCHGIN_UVLO 0x01 = VBUS is invalid. VCHGIN < VMBAT + VCHGIN2SYS and VCHGIN > VCHGIN_UVLO 0x02 = VBUS is invalid. VCHGIN > VCHGIN_OVLO 0x03 = VBUS is valid. VCHGIN > VCHGIN_UVLO, VCHGIN > VMBAT + VCHGIN2SYS, VCHGIN < VCHGIN_OVLO 7 R RSVD 0 Reserved www.maximintegrated.com Maxim Integrated 50 MAX77818 Dual Input, Power Path, 3A Switching Mode Charger with FG CHG_DETAILS_01 Register Bit Description (0xB4) NAME FUNCTION ADDR CHG_DTLS_01 Charger details 01 0xB4 BIT NAME 3:0 6:4 MODE R R CHG_DTLS BAT_DTLS www.maximintegrated.com RESET TYPE RESET O 0x00 DESCRIPTION 0000 Charger Details 0x00 = charger is in dead-battery prequalification or low-battery prequalification mode, CHG_OK = 1, VMBATT < VPQLB, TJ < TJSHDN 0x01 = charger is in fast-charge constant current mode, CHG_OK = 1, VMBATT < VBATREG, TJ < TJSHDN 0x02 = charger is in fast-charge constant voltage mode, CHG_OK = 1, VMBATT = VBATREG, TJ < TJSHDN 0x03 = charger is in top-off mode, CHG_OK = 1, VMBATT VBATREG, TJ < TJSHDN 0x04 = charger is in done mode, CHG_OK=0, VMBATT > VBATREG - VRSTRT, TJ < TJSHDN 0x06 = charger is in timer fault mode, CHG_OK = 0, VMBATT < VBATOV, if BAT_DTLS = 0b001 then VMBATT < VBATPQ, TJ < TJSHDN 0x07 = charger is in DETBAT = High suspend mode, CHG_OK = 0, VMBATT < VBATOV, if BAT_DTLS = 0b001 then VMBATT<VPQLB, TJ < TJSHDN 0x08 = Charger is off, charger input invalid and/or charger is disabled, CHG_OK = 1. 0x09 = Reserved 0x0A = Charger is off and the junction temperature is > TJSHDN, CHG_OK = 0. 0x0B = Charger is off because the watchdog timer expired, CHG_OK = 0. 0x0C-0x0F = Reserved 000 Battery Details 0x00 = No battery and the charger is suspended. 0x01 = VMBATT < VPQLB. This condition is also reported in the CHG_DTLS as 0x00 0x02 = the battery is taking longer than expected to charge. This could be due to high system currents, an old battery, a damaged battery or something else. Charging has suspended and the charger is in its timer fault mode. This condition is also reported in the CHG_DTLS as 0x06. 0x03 = the battery is okay and its voltage is greater than the minimum system voltage (VSYSMIN < VMBATT), QBAT is on and VSYS is approximately equal to VMBATT. 0x04 = the battery is okay but its voltage is low: VPQLB < VMBATT<VSYSMIN. QBAT is operating like an LDO to regulate VSYS to VSYSMIN. 0x05 = the battery voltage is greater than the battery overvoltage flag threshold (VBATOVF) or it has been greater than this threshold within the last 37.5ms. VBATOVF is set to a percentage above the VBATREG target as programmed by CHG_CV_PRM. Note that this flag is only be generated when there is a valid input or when the DCDC is operating as a boost. 0x06 = the battery is overcurrent or it has been overcurrent for at least 6ms since the last time this register has been read. 0x07 = Reserved In the event that multiple faults occur within the battery details category, overcurrent has priority followed by no battery, then overvoltage, then timer fault, then below prequel. Maxim Integrated 51 MAX77818 Dual Input, Power Path, 3A Switching Mode Charger with FG CHG_DETAILS_01 Register Bit Description (0xB4) (continued) BIT MODE 7 R NAME RESET TREG 0 DESCRIPTION Temperature Regulation Status 0 = The junction temperature is less than the threshold set by REGTEMP and the full charge current limit is available. 1 = The junction temperature is greater than the threshold set by REGTEMP and the charge current limit may be folding back to reduce power dissipation. CHG_DETAILS_02 Register Bit Description (0xB5) NAME FUNCTION ADDR CHG_DTLS_02 Charger details 02 0xB5 BIT NAME MODE RESET TYPE RESET O 0x00 DESCRIPTION Bypass Node Details. All bits in this family are independent from each other. They are grouped together only because they all relate to the health of the BYP node and any change in these bits generates a BYP_I interrupt. BYP_DTLS0 = OTGILIM = 0bxxx1 BYP_DTLS1 = BSTILIM = 0bxx1x BYP_DTLS2 = BCKNegILIM = 0bx1xx 3:0 R BYP_DTLS 0000 ******************************** 0x00=The bypass node is okay. 0bxxx1=The BYP to CHGIN switch (OTG switch) current limit was reached within the last 37.5ms. 0bxx1x=The BYP reverse boost converter has hit its current limit -- this condition persists for 37.5ms. 0bx1xx= The BYP buck converter has hit the max negative demand current limit. 7:4 R RSVD www.maximintegrated.com 00 Reserved Maxim Integrated 52 MAX77818 Dual Input, Power Path, 3A Switching Mode Charger with FG CHG_CNFG_00 Register Bit Description (0xB7) NAME FUNCTION ADDR CHG_CNFG_00 Charger configuration 00 0xB7 BIT 3:0 MODE R/W NAME MODE www.maximintegrated.com RESET 0101 TYPE RESET O 0x05 DESCRIPTION Smart Power Selector Configuration 0x00 = 0b0000 = charger = off, OTG = off, buck = off, boost = off. The QBAT switch is on to allow the battery to support the system. BYP may or may not be biased based on the CHGIN availability. 0x01 = 0b0001 = same as 0b0000 0x02 = 0b0010= same as 0b0000 0x03 = 0b0011= same as 0b0000 0x04 = 0b0100 = charger = off, OTG = off, buck = on, boost = off. When there is a valid input, the buck converter regulates the system voltage to be VBATREG. 0x05 = 0b0101 = charger = on, OTG = off, buck = on, boost = off. When there is a valid input, the battery is charging. VSYS is the larger of VSYSMIN and ~VMBATT + IMBATT x RBAT2SYS. 0x06 = 0b0110 = same as 0b101 0x07 = 0b0111 = same as 0b101 0x08 = 0b1000 = charger = off, OTG = off, buck = off, boost = on. The QBAT switch is on to allow the battery to support the system and the charger's DC-DC operates as a boost converter. The BYP voltage is regulated to VBYPSET. QCHGIN is off. . 0x09 = 0b1001=same as 0b1000 0x0A = 0b1010 = charger = off, OTG = on, buck = off, boost = on. The QBAT switch is on to allow the battery to support the system, the charger's DC-DC operates as a boost converter. QCHGIN is on allowing it to source current up to ICHGIN.OTG.MAX. The boost target voltage is 5.1V (VBYP.OTG) . 0x0B = reserved 0x0C = 0b1100 = charger = off, OTG = off, buck = on, boost = on. When there is a valid input, the system is supported from that input: VSYS = 4.2V. When input is invalid the boost is on with a target voltage that is VBYPSET 0x0D = 0b1101 = charger = on, OTG = off, buck = on, boost = on. When there is a valid input, the system is supported from that input: VSYS is the larger of VSYSMIN and ~VMBATT + IMBATT x RBAT2SYS. When input is invalid the boost is on with a target voltage that is VBYPSET 0x0E = 0b1110=charger=off, OTG = on, buck = on, boost = on. When there is a valid WCIN input, the system is supported from that input: VSYS = 4.2V and QCHGIN is on, allowing it to source current up to ICHGIN.OTG.MAX. When WCIN input is invalid the boost is on with a target voltage of 5.1V (VBYP.OTG). 0x0F = 0b1111 = charger = on, OTG = on, buck = on, boost = on. When there is a valid WCIN input, the system is supported from that input: VSYS is the larger of VSYSMIN and ~VMBATT + IMBATT x RBAT2SYS. QCHGIN is on allowing it to source current up to ICHGIN.OTG.MAX. When WCIN input is invalid the boost is on with a target voltage of 5.1V (VBYP.OTG) Maxim Integrated 53 MAX77818 Dual Input, Power Path, 3A Switching Mode Charger with FG CHG_CNFG_00 Register Bit Description (0xB7) (continued) BIT 4 MODE R/W NAME WDTEN RESET DESCRIPTION 0 Watchdog Timer Enable Bit. While enabled, the system controller must reset the watchdog timer within the timer period (tWD) for the charger to operate normally. Reset the watchdog timer by programming WDTCLR = 0x01. 0 = Watchdog Timer disabled 1 = Watchdog Timer enabled 5 R/W SPREAD 0 Spread Spectrum Feature Feature is operational both for 9V and 12V CHGIN input voltage. Feature is not guaranteed to be operational for 5V CHGIN/WCIN input voltage. When feature is not operational, it can be kept enabled without side effect. 0: Disabled 1: Enabled 6 R/W DISIBS 0 MBATT to SYS FET Disable Control 0 = MBATT to SYS FET is controlled by the power path state machine. 1 = MBATT to SYS FET is forced off. 7 R/W OTG_CTRL 0 OTG FET Control 0 = Forces the CHGIN input switch to be on when in Mode = 0x0E or 0x0F. 1 = The CHGIN turns off anytime power switches between WCIN and BATT. www.maximintegrated.com Maxim Integrated 54 MAX77818 Dual Input, Power Path, 3A Switching Mode Charger with FG CHG_CNFG_01 Register Bit Description (0xB8) NAME FUNCTION ADDR CHG_CNFG_01 Charger details 01 0xB8 NAME RESET BIT MODE TYPE RESET O R/W (protected with CHGPROT) 0x10 DESCRIPTION Fast-Charge Timer Duration (tFC) 0x00 = disable 0x01 = 4hrs 0x02 = 6hrs 0x03 = 8hrs 0x04 = 10hrs 0x05 = 12hrs 0x06 = 14hrs 0x07 = 16hrs 2:0 R/W FCHGTIME 001 3 R/W FSW 0 Switching Frequency Option 0: 4MHz 1: 2MHz 01 Charger Restart Threshold 0x00 = 100mV below the value programmed by CHG_CV_PRM 0x01 = 150mV below the value programmed by CHG_CV_PRM 0x02 = 200mV below the value programmed by CHG_CV_PRM 0x03 = Disabled 5:4 R/W CHG_RSTRT 6 R/W LSEL 0 Inductor Selection 0:0.47H (for 4MHz without restriction) 2MHz/0.47H option can be used only in the charge mode and is forbidden in following use cases: Boost mode Buck mode 1:1H (for 2MHz and 4MHz option) 7 R/W PQEN 0 Low Battery Prequalification Mode Enable 0 = Low battery prequalification mode is disabled. 1 = Low battery prequalification mode is enabled. www.maximintegrated.com Maxim Integrated 55 MAX77818 Dual Input, Power Path, 3A Switching Mode Charger with FG CHG_CNFG_02 Register Bit Description (0xB9) NAME FUNCTION ADDR CHG_CNFG_02 Charger configuration 02 0xB9 NAME RESET BIT MODE TYPE RESET O R/W (protected with CHGPROT) 0x09 DESCRIPTION Fast-Charge Current Selection. When the charger is enabled, the charge current limit is set by these bits. These bits range from 0.10A (0x00) to 3.0A (0x3C) in 50mA step. Note that the first 3 codes are all 100mA 5:0 R/W CHG_CC 001001 (450mA) Bits (mA) Bits (mA) Bits (mA) Bits (mA) 0x00 100 0x10 800 0x20 1600 0x30 2400 0x01 100 0x11 850 0x21 1650 0x31 2450 0x02 100 0x12 900 0x22 1700 0x32 2500 0x03 150 0x13 950 0x23 1750 0x33 2550 0x04 200 0x14 1000 0x24 1800 0x34 2600 0x05 250 0x15 1050 0x25 1850 0x35 2650 0x06 300 0x16 1100 0x26 1900 0x36 2700 0x07 350 0x17 1150 0x27 1950 0x37 2750 0x08 400 0x18 1200 0x28 2000 0x38 2800 0x09 450 0x19 1250 0x29 2050 0x39 2850 0x0A 500 0x1A 1300 0x2A 2100 0x3A 2900 0x0B 550 0x1B 1350 0x2B 2150 0x3B 2950 0x0C 600 0x1C 1400 0x2C 2200 0x3C 3000 0x0D 650 0x1D 1450 0x2D 2250 0x3D 3000 0x0E 700 0x1E 1500 0x2E 2300 0x3E 3000 0x0F 750 0x1F 1550 0x2F 2350 0x3F 3000 Note that the thermal foldback loop can reduce the battery charger's target current by ATJREG 7:6 R/W www.maximintegrated.com OTG_ILIM 00 CHGIN Output Current Limit in OTG Mode (ICHGIN.OTG.LIM) When MODE = 0x09 or 0x0A the CHGIN current limit is set at the following current limit: 00 = 500mA 01 = 900mA 10 =1200mA 11 = 1500mA Maxim Integrated 56 MAX77818 Dual Input, Power Path, 3A Switching Mode Charger with FG CHG_CNFG_03 Register Bit Description (0xBA): NAME FUNCTION ADDR TYPE RESET CHG_CNFG_03 Charger configuration 03 0xBA O R/W (protected with CHGPROT) 0xDA NAME RESET DESCRIPTION 010 (150mA) Top-Off Current Threshold. The charger transitions from its fast-charge constant voltage mode to its top-off mode when the charger current decays to the value programmed by this register. This transition generates a CHG_I interrupt and causes the CHG_DTLS register to report top-off mode. This transition also starts the top-off time as programmed by TO_TIME. 0x00 = 0.1A 0x01 = 0.125A 0x02 = 0.15A 0x03 = 0.175A 0x04 = 0.2A 0x05 = 0.25A 0x06 = 0.3A 0x07 = 0.35A 011 (30min) Top-Off Timer Setting 0x00 = 0min 0x01 = 10min 0x02 = 20min 0x03 = 30min 0x04 = 40min 0x05 = 50min 0x06 = 60min 0x07 = 70min BIT 2:0 5:3 7:6 MODE R/W R/W R/W www.maximintegrated.com TO_ITH TO_TIME ILIM 11 Program Buck Peak Current Limit 00: support ICHG=3.00A 01: support ICHG=2.75A 10: support ICHG= 2.50A 11: support ICHG=2.25A Maxim Integrated 57 MAX77818 Dual Input, Power Path, 3A Switching Mode Charger with FG CHG_CNFG_04 Register Bit Description (0xBB): NAME FUNCTION ADDR TYPE RESET CHG_CNFG_04 Charger configuration 04 0xBB O R/W (protected with CHGPROT) 0x96 NAME RESET BIT MODE DESCRIPTION Primary Charge Termination Voltage Setting When the charger is enabled and the main-battery temperature is < T3 if JEITA = 1 or < T4 if JEITA = 0, then, the charger's battery regulation voltage (VBATREG) is set by CHG_CV_PRM. 5:0 7:6 R/W CHG_CV_PRM R/W www.maximintegrated.com MINVSYS 010110 (4.2V) 10 (3.6V) BITS V BITS V BITS V 0x00 3.650 0x10 4.050 0x20 4.425 0x01 3.675 0x11 4.075 0x21 4.450 0x02 3.700 0x12 4.100 0x22 4.475 0x03 3.725 0x13 4.125 0x23 4.500 0x04 3.750 0x14 4.150 0x24 4.525 0x05 3.775 0x15 4.175 0x25 4.550 0x06 3.800 0x16 4.200 0x26 4.575 0x07 3.825 0x17 4.225 0x27 4.600 0x08 3.850 0x18 4.250 0x28 4.625 0x09 3.875 0x19 4.275 0x29 4.650 0x0A 3.900 0x1A 4.300 0x2A 4.675 0x0B 3.925 0x1B 4.325 0x2B 4.700 0x0C 3.950 0x1C 4.340 0x0D 3.975 0x1D 4.350 0x0E 4.000 0x1E 4.375 0x0F 4.025 0x1F 4.400 Minimum System Regulation Voltage (VSYSMIN) 0x00 = 3.4V 0x01 = 3.5V 0x02 = 3.6V 0x03 = 3.7V Maxim Integrated 58 MAX77818 Dual Input, Power Path, 3A Switching Mode Charger with FG CHG_CNFG_06 Register Bit Description (0xBD): NAME FUNCTION ADDR TYPE RESET CHG_CNFG_06 Charger configuration 06 0xBD O 0x00 NAME RESET BIT 1:0 MODE R/W WDTCLR DESCRIPTION 00 Watchdog Timer Clear Bits Writing 01 to these bits clears the watchdog timer when the watchdog timer is enabled. 0x00 = the watchdog timer is not cleared 0x01 = the watchdog timer is cleared 0x02 = the watchdog timer is not cleared 0x03 = the watchdog timer is not cleared Charger Settings Protection Bits Writing 11 to these bits unlocks the write capability for the registers who are protected with CHGPROT writing any value besides 11 locks these registers. 0x00 = write capability is locked 0x01 = write capability is locked 0x02 = write capability is locked 0x03 = write capability is unlocked 3:2 R/W CHGPROT 00 7:4 R/W RSVD 0000 Reserved CHG_CNFG_07 Register Bit Description (0xBE): NAME FUNCTION ADDR TYPE RESET CHG_CNFG_07 Charger configuration 07 0xBE O R/W (protected with CHGPROT) 0x40 BIT MODE NAME RESET DESCRIPTION 4:0 R/W RSVD 00000 Reserved 6:5 R/W REGTEMP 10 Junction Temperature Thermal Regulation Loop Set point. The charger's target current limit starts to foldback and the TREG bit is set if the junction temperature is greater than the REGTEMP setpoint. 0x00 = 85C 0x01 = 100C 0x02 = 115C 0x03 = 130C 7 R/W RSVD 0 Reserved www.maximintegrated.com Maxim Integrated 59 MAX77818 Dual Input, Power Path, 3A Switching Mode Charger with FG CHG_CNFG_09 Register Bit Description (0xC0): NAME FUNCTION ADDR TYPE RESET CHG_CNFG_09 Charger configuration 09 0xC0 O 0x0F NAME RESET BIT MODE DESCRIPTION Maximum Input Current Limit Selection 7-bit adjustment from 100mA to 4.0A in 33mA steps. Note that the first 4 codes are all 100mA: 6:0 7 R/W CHGIN_ILIM R/W www.maximintegrated.com RSVD 0x0F (0.50A) 0 Bits Unit (mA) Bits Unit (mA) Bits Unit (mA) Bits Unit (mA) 0x00 100 0x20 1067 0x40 2133 0x60 3200 0x01 100 0x21 1100 0x41 2167 0x61 3233 0x02 100 0x22 1133 0x42 2200 0x62 3267 0x03 100 0x23 1167 0x43 2233 0x63 3300 0x04 133 0x24 1200 0x44 2267 0x64 3333 0x05 167 0x25 1233 0x45 2300 0x65 3367 0x06 200 0x26 1267 0x46 2333 0x66 3400 0x07 233 0x27 1300 0x47 2367 0x67 3433 0x08 267 0x28 1333 0x48 2400 0x68 3467 0x09 300 0x29 1367 0x49 2433 0x69 3500 0x0A 333 0x2A 1400 0x4A 2467 0x6A 3533 0x0B 367 0x2B 1433 0x4B 2500 0x6B 3567 0x0C 400 0x2C 1467 0x4C 2533 0x6C 3600 0x0D 433 0x2D 1500 0x4D 2567 0x6D 3633 0x0E 467 0x2E 1533 0x4E 2600 0x6E 3667 0x0F 500 0x2F 1567 0x4F 2633 0x6F 3700 0x10 533 0x30 1600 0x50 2667 0x70 3733 0x11 567 0x31 1633 0x51 2700 0x71 3767 0x12 600 0x32 1667 0x52 2733 0x72 3800 0x13 633 0x33 1700 0x53 2767 0x73 3833 0x14 667 0x34 1733 0x54 2800 0x74 3867 0x15 700 0x35 1767 0x55 2833 0x75 3900 0x16 733 0x36 1800 0x56 2867 0x76 3933 0x17 767 0x37 1833 0x57 2900 0x77 3967 0x18 800 0x38 1867 0x58 2933 0x78 4000 0x19 833 0x39 1900 0x59 2967 0x79 4000 0x1A 867 0x3A 1933 0x5A 3000 0x7A 4000 0x1B 900 0x3B 1967 0x5B 3033 0x7B 4000 0x1C 933 0x3C 2000 0x5C 3067 0x7C 4000 0x1D 967 0x3D 2033 0x5D 3100 0x7D 4000 0x1E 1000 0x3E 2067 0x5E 3133 0x7E 4000 0x1F 1033 0x3F 2100 0x5F 3167 0x7F 4000 Reserved Maxim Integrated 60 MAX77818 Dual Input, Power Path, 3A Switching Mode Charger with FG CHG_CNFG_10 Register Bit Description (0xC1): NAME FUNCTION ADDR CHG_CNFG_10 Charger configuration 09 0xC1 NAME RESET BIT MODE TYPE RESET O 0x19 DESCRIPTION Maximum Input Current Limit Selection 6bit adjustment from 60mA to 1.260A in 20mA steps. Note that the first 4 codes are all 60mA: 5:0 7:6 R/W R/W www.maximintegrated.com WCIN_ILIM RSVD 0x19 (0.50A) 00 Bits (mA) Bits (mA) 0x00 60 0x20 640 0x01 60 0x21 660 0x02 60 0x22 680 0x03 60 0x23 700 0x04 80 0x24 720 0x05 100 0x25 740 0x06 120 0x26 760 0x07 140 0x27 780 0x08 160 0x28 800 0x09 180 0x29 820 0x0A 200 0x2A 840 0x0B 220 0x2B 860 0x0C 240 0x2C 880 0x0D 260 0x2D 900 0x0E 280 0x2E 920 0x0F 300 0x2F 940 0x10 320 0x30 960 0x11 340 0x31 980 0x12 360 0x32 1000 0x13 380 0x33 1020 0x14 400 0x34 1040 0x15 420 0x35 1060 0x16 440 0x36 1080 0x17 460 0x37 1100 0x18 480 0x38 1120 0x19 500 0x39 1140 1160 0x1A 520 0x3A 0x1B 540 0x3B 1180 0x1C 560 0x3C 1200 0x1D 580 0x3D 1220 0x1E 600 0x3E 1240 0x1F 620 0x3F 1260 Reserved Maxim Integrated 61 MAX77818 Dual Input, Power Path, 3A Switching Mode Charger with FG CHG_CNFG_11 Register Bit Description (0xC2): NAME FUNCTION ADDR TYPE RESET CHG_CNFG_11 Charger configuration 11 0xC2 O 0x00 NAME RESET BIT MODE DESCRIPTION Bypass Target Output Voltage in Boost Mode 3V (0x00) to 5.8V (0x70) in 0.025V steps. This setting is valid for the "boost only" mode (MODE = 0x08). 6:0 7 R/W R/W www.maximintegrated.com VBYPSET RSVD 0x00 (3V) 0 Bits Unit (mA) Bits Unit (mA) Bits Unit (mA) Bits Unit (mA) 0x00 3.000 0x20 3.800 0x40 4.600 0x60 5.400 0x01 3.025 0x21 3.825 0x41 4.625 0x61 5.425 0x02 3.050 0x22 3.850 0x42 4.650 0x62 5.450 0x03 3.075 0x23 3.875 0x43 4.675 0x63 5.475 0x04 3.100 0x24 3.900 0x44 4.700 0x64 5.500 0x05 3.125 0x25 3.925 0x45 4.725 0x65 5.525 0x06 3.150 0x26 3.950 0x46 4.750 0x66 5.550 0x07 3.175 0x27 3.975 0x47 4.775 0x67 5.575 0x08 3.200 0x28 4.000 0x48 4.800 0x68 5.600 0x09 3.225 0x29 4.025 0x49 4.825 0x69 5.625 0x0A 3.250 0x2A 4.050 0x4A 4.850 0x6A 5.650 0x0B 3.275 0x2B 4.075 0x4B 4.875 0x6B 5.675 0x0C 3.300 0x2C 4.100 0x4C 4.900 0x6C 5.700 0x0D 3.325 0x2D 4.125 0x4D 4.925 0x6D 5.725 0x0E 3.350 0x2E 4.150 0x4E 4.950 0x6E 5.750 0x0F 3.375 0x2F 4.175 0x4F 4.975 0x10 3.400 0x30 4.200 0x50 5.000 0x11 3.425 0x31 4.225 0x51 5.025 0x12 3.450 0x32 4.250 0x52 5.050 0x13 3.475 0x33 4.275 0x53 5.075 0x14 3.500 0x34 4.300 0x54 5.100 0x15 3.525 0x35 4.325 0x55 5.125 0x16 3.550 0x36 4.350 0x56 5.150 0x17 3.575 0x37 4.375 0x57 5.175 0x18 3.600 0x38 4.400 0x58 5.200 0x19 3.625 0x39 4.425 0x59 5.225 0x1A 3.650 0x3A 4.450 0x5A 5.250 0x1B 3.675 0x3B 4.475 0x5B 5.275 0x1C 3.700 0x3C 4.500 0x5C 5.300 0x1D 3.725 0x3D 4.525 0x5D 5.325 0x1E 3.750 0x3E 4.550 0x5E 5.350 0x1F 3.775 0x3F 4.575 0x5F 5.375 Reserved Maxim Integrated 62 MAX77818 Dual Input, Power Path, 3A Switching Mode Charger with FG CHG_CNFG_12 Register Bit Description (0xC3): NAME FUNCTION ADDR TYPE RESET CHG_CNFG_12 Charger configuration 12 0xC3 O 0x67 NAME RESET BIT 2:0 MODE R/W B2SOVRC DESCRIPTION 111 BAT to SYS Overcurrent Threshold 0x00 = Disabled 0x01 = 3.00A 0x02 = 3.25A 0x03 = 3.50A 0x04 = 3.75A 0x05 = 4.00A 0x06 = 4.25A 0x07 = 4.50A 4:3 R/W VCHGIN_REG 00 CHGIN Voltage Regulation Threshold (VCHGIN_REG) Adjustment The CHGIN to GND Minimum Turn-On Threshold (VCHGIN_UVLO) also scales with this adjustment. 0x00 = VCHGIN_REG = 4.3V and VCHGIN_UVLO = 4.5V 0x01 = VCHGIN_REG = 4.7V and VCHGIN_UVLO = 4.9V 0x02 = VCHGIN_REG = 4.8V and VCHGIN_UVLO = 5.0V 0x03 = VCHGIN_REG = 4.9V and VCHGIN_UVLO = 5.1V 5 R/W CHGINSEL 1 CHGIN/USB Input Channel Select 0 = Disabled 1 = Enabled 6 R/W WCINSEL 1 WCIN Input Channel Select 0 = Disabled 1 = Enabled 7 R/W Reserved 0 Reserved www.maximintegrated.com Maxim Integrated 63 MAX77818 Dual Input, Power Path, 3A Switching Mode Charger with FG PCB Layout Guide GND CWCIN 0603 CSL2 0402 CBYP 0603 CSL1 0402 CAVL 0402 CPVL 0603 CCHGIN 0603 CVFG 0201 CBYP 0603 0201 2016 INDUCTOR GND www.maximintegrated.com CBATT 0603 CSYS 0603 CSYS 0603 Maxim Integrated 64 MAX77818 Dual Input, Power Path, 3A Switching Mode Charger with FG Typical Application Circuit MICRO-B USB VBUS OVP IC (OPTIONAL) C8 2.2uF 16V (0603) VIO (FROM PMIC) 0.1uF 6.3V (0402) 200K A7 4.7uF 10V (0603) 1.8V to 5.5V D8 D9 WIRELESS CHARGER GND C9 A8 B5 200K 200K 200K A4 AP C3 A5 200K C5 B9 4.9V to AP USB PHY 1uF 10V (0402) 4.9V to CP USB PHY 1uF 10V (0402) 2.2uF 10V (0402) 10uF 10V (0603) CHGIN BYP CHGIN BYP CHGIN BYP WCIN BYP WCIN BST VIO SCL SDA INTB WCINOKB INOKB SAFEOUT1 CHGLX CHGLX CHGLX CHGLX SYS SYS SYS SYS SYS SYSA B7 SAFEOUT2 SYSA CHGPG D6 E7 C1 C2 B2 A2 B3 B4 B1 A6 E3 D1 D2 D3 D4 D5 www.maximintegrated.com BYP MAX77818 A3 SYS CHGIN AVL PVL TEST1 CHGPG CHGPG GSUBCG TEST2 BATT TEST3 BATT TEST4 BATT TEST5 BATT TEST6 VCCTEST DETBATB VBFG THMB B8 D7 E9 F7 F8 F9 G8 0.1uF 16V (0402) 0.47uH SYS 10uF 10V (0603) G9 E5 F5 G5 H5 H6 10uF 10V (0603) E1 F2 H7 H8 H9 G7 G3 G4 H3 BATT 10uF 10V (0603) VIO RB H4 B6 ID F1 0.1uF 16V (0402) G1 10K, 1% GND_D THM RINT H2 PK+ GND_A GND_A BAT_SP GND_A BAT_SN GND_A 10uF 16V (0603) E8 GND_Q GND_A 10uF 16V (0603) C7 10K G6 F6 PK- Maxim Integrated 65 MAX77818 Dual Input, Power Path, 3A Switching Mode Charger with FG Ordering Information PART MAX77818EWZ+ Package Information TEMP RANGE PIN-PACKAGE -40C to +85C 72-pin WLP 0.4mm pitch, 3.867mm x 3.608mm (0.015mm X and Y) +Denotes lead(Pb)-free/RoHS-compliant package. Chip Information PROCESS: BiCMOS www.maximintegrated.com For the latest package outline information and land patterns (footprints), go to www.maximintegrated.com/packages. Note that a "+", "#", or "-" in the package code indicates RoHS status only. Package drawings may show a different suffix character, but the drawing pertains to the package regardless of RoHS status. PACKAGE TYPE PACKAGE CODE OUTLINE NO. LAND PATTERN NO. 72 WLP W723B3+1 21-0477 Refer to Application Note 1891 Maxim Integrated 66 MAX77818 Dual Input, Power Path, 3A Switching Mode Charger with FG Revision History REVISION NUMBER REVISION DATE DESCRIPTION 0 6/15 Initial release 1 10/15 Corrected Figure 5 and minor errors PAGES CHANGED -- 19, 22, 27, 36 For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642, or visit Maxim Integrated's website at www.maximintegrated.com. Maxim Integrated cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim Integrated product. No circuit patent licenses are implied. Maxim Integrated reserves the right to change the circuitry and specifications without notice at any time. The parametric values (min and max limits) shown in the Electrical Characteristics table are guaranteed. Other parametric values quoted in this data sheet are provided for guidance. Maxim Integrated and the Maxim Integrated logo are trademarks of Maxim Integrated Products, Inc. (c) 2015 Maxim Integrated Products, Inc. 67 Mouser Electronics Authorized Distributor Click to View Pricing, Inventory, Delivery & Lifecycle Information: Maxim Integrated: MAX77818EWZ+T