SM3320-BATT-EV/NOPB - Texas Instruments

Application Report

SNOSB76C–December 2010–Revised May 2013

AN-2121 SolarMagic™ SM3320-BATT-EV Charge

Controller Reference Design

.....................................................................................................................................................

ABSTRACT

The SM72442 MPPT digital controller and SM72295 photovoltaic full bridge drivers are designed to control

high-efficiency DC/DC conversion used in photovoltaic applications. This application report details the

usage of those devices in a battery charging application. The reference design is meant to provide support

for a wide variety of implementations, however, unless otherwise noted, this reference design system is

shown charging a 12V commercial automotive lead acid battery.

Contents

1 Charging Profile ............................................................................................................. 3

2 Features ...................................................................................................................... 3

3 Quick Setup Procedure .................................................................................................... 4

4 10V Power Supply .......................................................................................................... 4

5 DC/DC Converter ........................................................................................................... 5

6 Programmable Modes/Gain Settings ..................................................................................... 6

7 Current Sense Gains and Offset .......................................................................................... 6

8 Start-Up Circuitry ............................................................................................................ 7

9 Output FET Disabling ....................................................................................................... 8

10 Output Current Regulation ................................................................................................. 9

11 Voltage Regulation .......................................................................................................... 9

12 MPPT ....................................................................................................................... 10

13 Microcontroller Functions ................................................................................................. 11

13.1 Normal Operation ................................................................................................. 11

13.2 Start-Up Operation ............................................................................................... 11

13.3 Safety Feature .................................................................................................... 11

14 Microcontroller Program Code ........................................................................................... 13

14.1 Function: check_lead_acid() .................................................................................... 14

14.2 Function: Main() .................................................................................................. 14

14.3 Function: get_i2c_data ........................................................................................... 14

14.4 Function: send_i2c_command(char number) ................................................................. 15

14.5 Function: Set_Voutmax() ........................................................................................ 15

14.6 Function: Check_low_current() ................................................................................. 15

15 Charging a Li-ion Battery ................................................................................................. 15

16 Bill of Materials ............................................................................................................. 17

17 Charge Controller System Schematic .................................................................................. 19

List of Figures

1 Lead-Acid Charging Profile ................................................................................................ 3

2 System Connection......................................................................................................... 4

3 10V Power Supply .......................................................................................................... 4

4 DC/DC Converter Stage ................................................................................................... 5

5 Buck Gate Drive Signals From SM72442................................................................................ 5

SolarMagic is a trademark of Texas Instruments.

All other trademarks are the property of their respective owners.

SNOSB76C–December 2010–Revised May 2013 AN-2121 SolarMagic™ SM3320-BATT-EV Charge Controller Reference

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6 Switch Nodes in Buck Mode............................................................................................... 5

7 Boost Gate Drive Signals From SM72442............................................................................... 6

8 Switch Nodes in Boost Mode.............................................................................................. 6

9 Start-Up Boost Circuitry.................................................................................................... 7

10 Start-up Circuit Timing Diagram........................................................................................... 8

11 Start-up VPanel < VBatt......................................................................................................... 8

12 Start-up Detail of Battery Current......................................................................................... 8

13 Charging Waveforms During Float ....................................................................................... 9

14 Battery Charging with VPanel < VBattery (Boost) ........................................................................... 10

15 Battery Charging with VPanel > VBattery (Buck) ............................................................................ 10

16 Basic Operational Flowchart ............................................................................................. 12

17 Microcontroller Code Flowchart.......................................................................................... 13

18 Microcontroller Code Block Diagram.................................................................................... 15

19 Li-ion Charge Profile ...................................................................................................... 16

20 Charge Controller System Schematic, Part 1.......................................................................... 19

21 Charge Controller System Schematic, Part 2.......................................................................... 20

2AN-2121 SolarMagic™ SM3320-BATT-EV Charge Controller Reference SNOSB76C–December 2010–Revised May 2013

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Charging Profile

1 Charging Profile

Figure 1 shows the lead-acid charging profile used in this reference design.

If the battery voltage is very low, a slow charge current is applied and limited until the voltage rises above

a pre-set threshold value Vt. The full charge current is then applied. Once full charge is detected on the

voltage of the battery, the system switches to a floating charge and maintains the battery voltage at a fixed

threshold. At any time, the system will run in MPPT mode if the available power is lower than the power

required to achieve voltage or current regulation.

Figure 1. Lead-Acid Charging Profile

2 Features

• 12V Lead Acid Battery

• Vin range = 15V to 45V Vmp (50V Voc)

• Max Input Current: Isc = 11A

• MPPT algorithm for optimized photovoltaic applications

• Up to 9A charging current

• Reverse current protection

• Trickle charge and fast charge mode

• Up to 98% converter efficiency

• 14.2V max charge voltage, 13.5V floating voltage

• Output voltage set-points can be re programmed

SNOSB76C–December 2010–Revised May 2013 AN-2121 SolarMagic™ SM3320-BATT-EV Charge Controller Reference

Design

Quick Setup Procedure

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3 Quick Setup Procedure

Step 1: Verify lead-acid battery voltage less than 12V, higher than 10V.

Step 2: Connect battery to output terminals as shown in Figure 2.

Step 3: Connect Solar panel or Solar Array Simulator to the input terminals as shown in Figure 2.

Step 4: Verify battery charging current up to 9A (Average slightly under 9A).

Step 5: If battery current low, verify input operates at maximum power point voltage as specified by the

panel manufacturer.

Step 6: Verify charging profile follows the profile shown in Figure 1.

Figure 2. System Connection

4 10V Power Supply

The circuit shown in Figure 3 will provide a 10V power supply rail required to properly bias the SM72295

gate driver. The system can be configured to work with solar panels up to100V (with proper components

sizing) and down to 12V Vmp.

Figure 3. 10V Power Supply

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DC/DC Converter

5 DC/DC Converter

The DC/DC converter stage is a step up/step down four switch converter as shown in Figure 4. This stage

transfers the power from the PV panel to the load.

Figure 4. DC/DC Converter Stage

C18, R11, and D15 as shown in the system schematic in Figure 20, form a snubber to reduce ripple on

the switch node on the “Buck” side of the converter. C19,R14 and D14 form a snubber circuit to reduce

ripple on the switch node of the “Boost” side of the converter.

When the circuit operates in Buck mode, the Boost switch node will issue small pulses at a lower

frequency in order to recharge the Bootstrap capacitor of Q2. Likewise, in Boost mode, the Buck switch

node will pulse to recharge the bootstrap capacitor of Q1.

Specific design guidelines for the DC/DC converter can be found in the AN-2124 Power Circuit Design for

SolarMagic SM3320 Application Report (SNOSB84) for power optimizers.

Specific timings related to the switches can be found in SM72442 Programmable Maximum Power Point

Tracking Controller for Photovoltaic Solar Panels (SNVS689) and SM72295 Photovoltaic Full Bridge Driver

(SNVS688).

The waveforms in Figure 5 through Figure 8 are examples of the switching signals of the DC/DC converter

stage.

If the system is to be used at elevated power levels causing high temperature increases in MOSFETs Q1,

Q2, Q3, and/or Q4, we recommend the use of a proper heatsink for the MOSFETs, especially at higher

ambient temperatures. Care must be taken to prevent electrical contact between the drains of the

MOSFETs in the process of proper heatsinking.

Figure 5. Buck Gate Drive Signals From SM72442 Figure 6. Switch Nodes in Buck Mode

SNOSB76C–December 2010–Revised May 2013 AN-2121 SolarMagic™ SM3320-BATT-EV Charge Controller Reference

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Programmable Modes/Gain Settings

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Figure 7. Boost Gate Drive Signals From SM72442 Figure 8. Switch Nodes in Boost Mode

6 Programmable Modes/Gain Settings

The voltage dividers for the output voltage sensing are set to ensure high resolution of the output voltage

while providing a safe voltage (<5V) for the SM72442 and microcontroller.

The default resistor setting in this reference design sets a full scale of 30V.

The programmable modes of the SM72442 used in this design are as follows:

• VADC2 = 5V (50% of 4sec in BB)

• VADC6 = 5V (startup at 0mA)

• VADC0 = 0V. This value provides an initial output voltage limit of 19V. However, this limit will be

modified by the microcontroller through I2C before the controller begins supplying the battery.

• VADC4 = 5V. Current limiting will be done externally so the max current limit can be set at full scale.

7 Current Sense Gains and Offset

The gain of the current sensing circuit depends on the application. In our system it was set with a gain of

0.44 V/Amps. The gain is set by a pull-down resistor at the output of IOUT (12) and IIN (3) pins of the

SM72295 as stated in the data sheet of the device.

6AN-2121 SolarMagic™ SM3320-BATT-EV Charge Controller Reference SNOSB76C–December 2010–Revised May 2013

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Start-Up Circuitry

8 Start-Up Circuitry

If the panel voltage is lower than the battery voltage, a start up circuit (Figure 9) is required to force the

duty cycle high enough to create a flow of current to the battery. Once current is established, the circuit

can be turned off to allow MPPT operation to perform.

Figure 9. Start-Up Boost Circuitry

As long as the start-up circuit is activated, the duty cycle will increase every 1ms up to its maximum value.

However, the duty cycle will still be limited by the SM72442’s internal output voltage limiter.

The circuit is turned on when the anode of D101 and the cathode of D100 are kept at 5V. It is disabled

when that node is set at 0V.

The circuit should be disabled 5ms after current begins to flow into the battery to allow proper MPPT

operation.

If the current drops to 0 for any reason (no light, reset, and so on) the start-up circuit can be re-engaged

according to the timing diagram in Figure 10.

This circuit operates by sensing the average value of the gate voltage on the main buck switch (Q1) and

main boost switch (Q4). This value is fed back to the input current sense of the SM72442. At the same

time, a constant 4.4V is set at the input voltage sense pin of the SM72442. This results in the SM72442

measuring a virtual power that increases each time the duty cycle is increased and decreases each time

the duty cycle is decreased. The SM72442 will track this virtual power and increase the duty cycle of the

converter continuously. When this circuit is de-activated, the real input voltage and current appear at the

sensing pins of the SM72442 chip which will then perform regular MPPT operation.

SNOSB76C–December 2010–Revised May 2013 AN-2121 SolarMagic™ SM3320-BATT-EV Charge Controller Reference

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Output FET Disabling

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Figure 10. Start-up Circuit Timing Diagram

Figure 11 shows the expected waveform if the panel voltage is less than the battery voltage. The panel

Vmp for this example is 12V @ 3A and the battery voltage is at 25V. Figure 12 showcases the magnified

version of the battery current shown in Figure 11.

NOTE: To highlight the boosting capability of the system and start-up circuit, the board has been re-

configured to run with a 24V battery for the experiments shown in Figure 11 and Figure 12.

Figure 11. Start-up VPanel < VBatt Figure 12. Start-up Detail of Battery Current

9 Output FET Disabling

Q9 keep the topside output FET Q2 from turning on. The power will flow through the parallel diode D7

instead. This prevents the battery from discharging into the PV panels. Q2 can be disabled using the

microcontroller or a comparator (U12A) connected to the output current sensing: when current drops

below the threshold value, Q2 is disabled. The threshold is set to 1A by default.

8AN-2121 SolarMagic™ SM3320-BATT-EV Charge Controller Reference SNOSB76C–December 2010–Revised May 2013

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Vsetpoint = Reg3[29:20]

1024 x VDDA x R51 + R52 + R53

R53

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Output Current Regulation

10 Output Current Regulation

Current regulation is enforced by a comparator (U11A). The current setting can be switched from a low

current limit to a high current limit with a bit set by the microcontroller. When microcontroller pin RC5 (pin

number 16) is set to high impedance, the high current limit is set. When pin RC5 is set to 0V, the low

current limit is set.

In this design, the high current limit is set to 9A and the low current limit to 0.5A.

11 Voltage Regulation

Voltage regulation with the SM72442 is performed internally. The initial output voltage setting is set

through pin A0 (0-5V). The output voltage set point can then be changed through the I2C communication

interface by setting the register 0x03 bits 20:29 to the required voltage set point and bit 46 to 1.

Figure 13 shows the system performing voltage regulation on the battery at 13.5V.

In addition to the voltage regulation, a comparator (U11B) will reset the SM72442 and cause the DC/DC

converter to shutdown if the output voltage increases beyond the values set by R71 and R72. When the

negative input of the comparator reaches over 5V, the SM72442 controller will be reset. The default value

corresponds to 14.6V battery voltage.

(1)

Figure 13. Charging Waveforms During Float

SNOSB76C–December 2010–Revised May 2013 AN-2121 SolarMagic™ SM3320-BATT-EV Charge Controller Reference

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MPPT

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12 MPPT

The SM72442 chip will perform the MPPT function using an implementation of the Perturb and Observe

algorithm method. The MPPT algorithm will extract maximum power from the solar panel and deliver it to

the battery regardless of the panel’s characteristics. Figure 14 and Figure 15 show the effect on the panel

voltage as the MPPT algorithm maintains constant power at the panel regardless of the voltage on the

battery.

Figure 14. Battery Charging with Figure 15. Battery Charging with

VPanel < VBattery (Boost) VPanel > VBattery (Buck)

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Microcontroller Functions

13 Microcontroller Functions

The charge profile is implemented in the current design using a PIC16F722 microcontroller.

13.1 Normal Operation

The flowchart in Figure 16 details the operation of the microcontroller needed to achieve the desired

charging pattern.

Modification to this flowchart can easily be done and programmed to include:

• Modified threshold depending on temperature (if battery temperature information available).

• Timer to maintain high voltage threshold for a certain time before switching to floating charge to

maximize energy stored in the battery.

• Pulse charging during the float charge period.

The microcontroller is programmed using a 10 pin CLE-105 connector (J5). The connections are:

• 1: NC (Not Connected)

• 2: PGD/ICSPDAT

• 3: GND

• 4: PGC/ICSPCLK

• 5: NC

• 6: GND

• 7: +5Vdc

• 8: MCLR!

• 9: GND

• 10: NC

Refer to the Microchip website for proper programming/debugging of the PIC16F family microcontrollers.

13.2 Start-Up Operation

At start-up, the microcontroller needs to assess the PV and battery voltage to verify proper connection and

values.

If the values are within the specified range (correct panel and battery voltage), the microcontroller enables

the charge by releasing the RESET line of the SM72442 chip. If needed, the start-up circuit is turned on

by setting RB5 to ‘1’ (5V) (If the microcontroller used in the application is running below 5V, a level shifting

circuit will be necessary).

Once current begins to flow in the battery the start-up circuit can be released.

While the start-up circuit is enabled, the panel current and voltage are not available through I2C. The

corresponding registers can be read but will not contain the correct values.

13.3 Safety Feature

The microcontroller is programmed by default to stop charging the battery if the output voltage is above

14.5V or below 8V.

SNOSB76C–December 2010–Revised May 2013 AN-2121 SolarMagic™ SM3320-BATT-EV Charge Controller Reference

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Microcontroller Functions

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Figure 16. Basic Operational Flowchart

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Initialization

Release SM72442

Reset

Set SM72442

Output Voltage to

14.3V

Vbatt>14.5V?

Vbatt<8V?

Vbatt>14.2V? Set voltage to

13.5V

Vbatt<10V? Set low current

limit

Set high current

limit

Defective battery

or no batter

Engage SM72442

Reset

Wait

Yes

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Microcontroller Program Code

14 Microcontroller Program Code

The flowchart in Figure 17 is representative of the code programmed inside the microcontroller.

The check_lead_acid function issues a value depending on the state of the battery as detected by the

voltage. The main function uses this value to issue the proper action. The other functions in the program

are essentially I2C driver functions and low level port setup functions.

Figure 17. Microcontroller Code Flowchart

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Microcontroller Program Code

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14.1 Function: check_lead_acid()

This function senses the battery voltage through the microcontroller’s A/D converter. The A/D conversion

is needed because the current limiting circuit in hardware acts on the voltage sensing line of the

SM72442. Therefore, when the system is running in high current mode, the voltage sensed by the

SM72442 is not the battery voltage. If the current limitation is not necessary, such as panels with limited

power capabilities, the voltage used by the check_lead_acid() function could be changed to the value

recovered from the SM72442 through I2C instead of using the microcontroller’s ADC.

This function verifies the state of the battery by sensing its voltage and returns an 8 bit number related to

the state of the battery:

• 0: No change

• 1: Battery reached the full State Of Charge voltage

• 2: Battery voltage is low

• 3: Battery voltage is too low or battery damaged/disconnected

• 4: Battery voltage is above the acceptable value: battery damaged or disconnected

• 5: Battery voltage has reached above 13.6V. This is usually due to the lower limit on the duty cycle of

the buck converter. When the battery stays in floating charge state for too long, the converter will keep

pumping a minimum current into the battery which could result in an increase of the battery voltage

beyond the desired floating charge voltage range.

• 6: Battery voltage has returned to an acceptable value

States 5 and 6 correspond to the state of charge of the battery after it has reached it's floating charge

state value of 13.5V. When “5” is returned by this function, the program will completely cut the charge into

the battery (by issuing a reset to the SM72442 via PORTB of the microcontroller). When “6” is returned by

this function, the program will re-enable the floating charge into the battery by releasing the reset on the

SM72442.

14.2 Function: Main()

The “Main” function calls the” Init()” function, which simply initializes the variables and the registers. The

program then enters an infinite while-loop in which the values of the sensed voltages and current are

recovered from the SM72442 through I2C. The function “check_lead_acid()” is called and returns a value

based on the voltage of the battery. The “Main” function uses this value to modify the behavior of the

system. The following lists the values returned from the “check_lead_acid()” function the corresponding

action the “Main” function will take:

• 1 (fully charged battery): The floating charge voltage setpoint will be sent to SM72442 through I2C

• 2 (heavily discharged battery): Trickle charge will be applied

• 3 (battery voltage too low): System shuts down by keeping the SM72442 in reset mode (bit RB2 set)

• 4 (battery voltage too high): System shuts down by keeping the SM72442 in reset mode (bit RB2 set)

• 5 (battery voltage slightly high in floating charge): System shuts down by keeping the SM72442 in

reset mode (bit RB2 set) and hysteresis flag set

• 6 (battery voltage dropped below 13V after hysteresis flag set): Re-enable SM72442, hysteresis flag

reset

The Main function also resets the watchdog timer once every iteration of the while-loop.

14.3 Function: get_i2c_data

This function reads the sampled voltage of pin AIIN(19), AVIN(15), AIOUT(21), and AVOUT(17) of the

SM72442. The data is fetched through the I2C channel. The function updates the global variable “outval”

which is an array of unsigned 16 bit integers. The data only occupies 10bits of each integer (full

scale=1023).

• outval[0] = input current

• outval[1] = input voltage

• outval[2] = output current

• outval[3] = output voltage

14 AN-2121 SolarMagic™ SM3320-BATT-EV Charge Controller Reference SNOSB76C–December 2010–Revised May 2013

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Main

- Call proper functions

- Set Voltage Levels

- Enable/disable SM72442

Check_Lead_Acid

- Sense battery voltage

- Return value of battery state

Init()

Setup

registers

Send_i2c_command

Send the content of the communication

buffer on the I2C bus

Check_low_current

Check if current is very low

Get_i2c_data

- Send request for data through I2C

- Recover and parse data in global variable

Set_Vout_max

Setup I2C communication words to

change the output voltage level

controlled by the SM72442

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Charging a Li-ion Battery

14.4 Function: send_i2c_command(char number)

Sends an I2C communication string. Each byte sent is stored in the global array “i2c_buffer”. The

argument “number” indicates how many bytes from the buffer will be sent (starting with i2c_buffer[0]).

Refer to the data sheet and I2C and SM_bus standards documentation for complete protocol information.

The main use of this function is to change the voltage limit settings in the SM72442.

14.5 Function: Set_Voutmax()

This will read the “voutmax” variable set in the main and sends the proper I2C command to the SM72442

to regulate that voltage.

14.6 Function: Check_low_current()

This function is called by the “Main” function and controls the start-up circuitry to force the duty cycle of

the converter up if the current becomes close to 0.

Figure 18 summarizes the overall structure of the program: (arrows from the main represent calls to the

functions)

Figure 18. Microcontroller Code Block Diagram

15 Charging a Li-ion Battery

Although this evaluation board was specifically designed for charging a lead-acid battery, it can be re-

configured to accommodate the Li-ion chemistry battery through a combination of hardware and software

changes. In order to re-configure the board for Li-ion charging, the following steps need to be done:

1. The voltage sensing resistors R103, R104, R51, R52 and R53 and OVP resistors R71 and R72 need

to be changed to the proper values. It is critical for this application that the full scale voltage range for

sensing is as close as possible to the voltage of the battery to maximize the resolution of the sensed

voltage. The level of the OVP circuit needs to be scaled so that it does not trigger when the battery

approaches full SOC but at a voltage slightly higher.

SNOSB76C–December 2010–Revised May 2013 AN-2121 SolarMagic™ SM3320-BATT-EV Charge Controller Reference

Design

Voltage Limit

Charge

Cut-Off

Voltage

Current

time

VHARD_OVP = VBAT x R72

R71 + R72

VAVOUT = VBAT x R53

R51 + R52 + R53

VA12 = VBAT x R103

R103 + R104

Charging a Li-ion Battery

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• R103 and R104 set the voltage at the input of the microcontroller. The voltage at the input of the

microcontroller is:

(2)

• R103 and R104 should be chosen so that the maximum expected battery voltage creates a voltage

close to 5V to maximize resolution (but less than 5V to avoid saturating the measure).

• R51, R52 and R53 are for the voltage measurement of the SM72442 and should be modified in the

same way:

(3)

• R21 needs to be set to zero ohm (short).

• Once the values are picked, the proper threshold needs to be programmed through I2C. The

maximum level (0x3FF) is now VAVOUT = 5V at the input of the SM72442.

• Finally, the overvoltage protection should be adjusted to:

(4)

• The OVP level is set at VHARD_OVP = 5v.

2. The proper voltage setpoints and charging curve need to be programmed in the microcontroller. The

initial voltage limit is set by R28 and R38. Voltage limit setpoint is AVOUT = A0. Once overridden

through I2C, the voltage at A0 is not used anymore. Hence, there is the option of setting the value

through resistors R28 and R38 or by programming it from the microcontroller into SM72442 through

I2C each time the SM72442 is reset/powered.

3. Proper current limits also need to be set if required by the battery model. The current limit value is set

when the voltage at pin 3 of U11A equals the voltage at pin 2. Hence, R111 and R112 will need to be

adjusted accordingly.

4. The software needs to be changed to follow the Li-ion charge control profile: battery voltage is set

either by hardware as stated above, which requires no action from the software, or it is set from the

microcontroller through the I2C interface similar to the Lead Acid battery.

5. Finally, the software needs to include the full State-Of-Charge cut-off: When the battery reaches its full

voltage and current has dropped below 500mA (can vary depending on battery), charge is cut-off and

the battery is considered fully charged (no trickle charge of Li-ion batteries should be done). It is

important to remember that current can drop below 500mA during the charge when solar power

becomes unavailable (low light intensity). Therefore the charge cut-off needs to be programmed to

occur only when the battery voltage is at the limit AND current has dropped below the required

threshold.

Figure 19 shows the typical charging profile for a Li-ion battery.

Figure 19. Li-ion Charge Profile

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Bill of Materials

16 Bill of Materials

Designator Description Manufacturer Part Number Qty

1 U17 Flash-Based, 8-Bit CMOS Microcontroller, Microchip Technology PIC16F722-E/SS or 1

2K (x14-Bit words) Program Memory, 128 PIC16F722-I/SS

Bytes Data Memory, 25 I/O pins, 28-Pin

SOIC, Standard VDD Range, Extended

Temperature

2 C1, C2, C3, C4, C5, Ceramic, X7R, 50V, 10% MuRata C3225X7R1H225k/2.50 32

C6, C7, C8, C9, C10,

C11, C12, C13, C14,

C16, C20, C25, C27,

C28, C30, C36, C42,

C44, C45, C47, C48,

C53, C55, C57, C67,

C70, C72

3 C15, C17, C22, C26, Ceramic, X7R, 25V, 10% MuRata GRM188R71E104KA01D 10

C32, C49, C50, C51,

C52, C65

4 C18, C19 Ceramic, C0G/NP0, 100V, 5% AVX 08051A471JAT2A 2

5 C21 Ceramic, X7R, 100V, 10% Taiyo Yuden HMK212B7104KG-T 1

6 C23, C33, C34, C38 Ceramic, X7R, 16V, 10% Taiyo Yuden EMK212B7225KG-T 4

7 C24 Ceramic, X7R, 50V, 10% MuRata GRM188R71H331KA01D 1

8 C29, C37, C39, C59 Ceramic, X7R, 100V, 20% AVX 06031C103MAT2A 4

9 C31, C35, C40 Ceramic, X7R, 16V, 10% Taiyo Yuden EMK212B7105KG-T 3

10 C46, C54 Ceramic, X7R, 16V, 10% AVX 0805YC474KAT2A 2

11 C58, C60, C61, C62, Ceramic, C0G/NP0, 100V, 5% TDK C1608C0G2A102J 6

C66, C69

12 C73 Ceramic, C0G/NP0, 50V, 5% TDK C1608C0G1H151J 1

13 C88 CAP, CERM, 0.1uF, 25V, +/-5%, X7R, AVX 06033C104JAT2A 1

0603

14 C100, C102 CAP, CERM, 1000pF, 100V, +/-10%, X8R, TDK C1608X8R2A102K 2

0603

15 C101 CAP, CERM, 0.1uF, 16V, +/-5%, X7R, AVX 0603YC104JAT2A 1

0603

16 D2, D7, D9, D12, D13, Vr = 100V, Io = 1A, Vf = 0.77V Diodes Inc. DFLS1100-7 7

D14, D15

17 D3, D4, D5, D6 Vr = 30V, Io = 1A, Vf = 0.47V ON Semiconductor MBR130T1G 4

18 D100, D101 Vr = 30V, Io = 0.2A, Vf = 0.65V Diodes Inc. BAT54-7-F 2

20 J1, J2, J3, J4 PC Quick-Fit 0.250 Tab Keystone 4908 4

21 J5 CONN RCPT 10POS .8MM DL GOLD SAMTEC CLE-105-01-G-DV 1

SMD

22 J11, J12, J13, J14 200 mill pad with 165 mill hole NONE NONE 4

23 L4 Shielded Drum Core, 0.56A, 0.907 Ohm Coiltronics DR74-221-R 1

24 P1 Header, TH, 100mil, 1x2, Tin plated, 230 Samtec Inc. TSW-102-07-T-S 1

mil above insulator

25 Q1, Q2, Q3, Q4 40A, 53nC, rDS(on) @ 4.5V = 0.018 Ohm International Rectifier IRF3205ZPBF 4

26 Q7, Q8, Q9 0.26A, 0.81nC, rDS(on) @ 4.5V = 3 ON Semiconductor 2N7002ET1G 3

27 Q11 Transistor, NPN, 40V, 0.15A, SOT-23 Diodes Inc. MMBT4401-7-F 1

28 Q200 MOSFET, P-CH, -50V, -130A, SOT-323 Diodes Inc. BSS84W-7-F 1

29 R1, R10 1%, 2W Stackpole CSNL 2 0.004 1% R 2

30 R2, R54 1%, 0.125W Vishay-Dale CRCW0805178kFKEA 2

SNOSB76C–December 2010–Revised May 2013 AN-2121 SolarMagic™ SM3320-BATT-EV Charge Controller Reference Design

Bill of Materials

www.ti.com

Designator Description Manufacturer Part Number Qty

31 R3, R4, R22, R23, 1%, 0.1W Vishay-Dale CRCW060310k0FKEA 21

R30, R36, R42, R43,

R45, R72, R100,

R101, R102, R105,

R106, R111, R119,

R120, R121, R300,

R400

32 R5 1%, 0.1W Vishay-Dale CRCW0603124kFKEA 1

33 R6 1%, 0.125W Vishay-Dale CRCW08051R00FNEA 1

34 R7, R13 1%, 0.25W Vishay-Dale CRCW120619k6FKEA 2

35 R8, R12, R24, R34 1%, 0.1W Vishay-Dale CRCW0603499RFKEA 4

36 R9 1%, 0.1W Vishay-Dale CRCW060312k4FKEA 1

37 R11, R14 1%, 1W Vishay-Dale CRCW121810R0FKEK 2

38 R15 1%, 0.1W Vishay-Dale CRCW06034k22FKEA 1

39 R17 1%, 0.1W Panasonic ERJ-3RQFR33V 1

40 R18, R19 RES, 10 ohm, 5%, 0.125W, 0805 Vishay-Dale CRCW080510R0JNEA 2

41 R20, R29, R31, R47, 1%, 0.1W, RES, 2.00k ohm, 1%, 0.1W, Vishay-Dale CRCW06032k00FKEA 5

R48 0603

42 R21 1%, 0.1W Vishay-Dale CRCW060349R9FKEA 1

43 R25, R35, R37, R44 5%, 0.1W Vishay-Dale CRCW06030000Z0EA 4

44 R26, R56, R87, R116 1%, 0.1W Vishay-Dale CRCW060360k4FKEA 4

45 R71, R73 1%, 0.1W, RES, 19.1k ohm, 1%, 0.1W, Vishay-Dale CRCW060319k1FKEA 3

0603

46 R32, R33 RES, 4.99 ohm, 1%, 0.125W, 0805 Vishay-Dale CRCW08054R99FNEA 2

47 R38 1%, 0.1W Vishay-Dale CRCW060331k6FKEA 1

48 R39 RES, 1.00Meg ohm, 1%, 0.1W, 0603 Vishay-Dale CRCW06031M00FKEA 1

49 R40 1%, 0.1W Vishay-Dale CRCW0603150kFKEA 1

50 R41 RES, 45.3k ohm, 1%, 0.1W, 0603 Vishay-Dale CRCW060345K3FKEA 1

51 R51, R52 RES, 12.4k ohm, 1%, 0.25W, 1206 Vishay-Dale CRCW120612K4FKEA 2

52 R53, R103 RES, 4.02k ohm, 1%, 0.1W, 0603 Vishay-Dale CRCW06034K02FKEA 2

54 R104 RES, 24.9k ohm, 1%, 0.1W, 0603 Vishay-Dale CRCW060324K9FKEA 1

55 R107, R108 RES, 270k ohm, 1%, 0.1W, 0603 Yageo America RC0603FR-07270KL 2

56 R109 RES, 340k ohm, 1%, 0.1W, 0603 Yageo America RC0603FR-07340KL 1

57 R110, R122 RES, 100k ohm, 1%, 0.1W, 0603 Yageo America RC0603FR-07100KL 2

58 R112 RES, 511k ohm, 1%, 0.1W, 0603 Vishay-Dale CRCW0603511KFKEA 1

59 R113, R117 RES, 22k ohm, 5%, 0.1W, 0603 Vishay-Dale CRCW060322K0JNEA 2

61 R118 RES, 105k ohm, 1%, 0.1W, 0603 Vishay-Dale CRCW0603105KFKEA 1

62 R200 RES, 604 ohm, 1%, 0.1W, 0603 Vishay-Dale CRCW0603604RFKEA 1

63 R500, R600 RES, 100k ohm, 1%, 0.1W, 0603 Vishay-Dale CRCW0603100KFKEA 2

64 TP1, TP2 Test Point, SMT, Miniature Keystone Electronics 5015 2

65 U1 150 mA, 100V Step-Down Switching Texas Instruments SM72485 1

Regulator

66 U2, U3 1.6V, LLP-6 Factory Preset Temperature Texas Instruments SM72480 2

Switch and Temperature Sensor

67 U5 Series of Adjustable Micropower Voltage Texas Instruments SM72238 1

Regulators

68 U7 Driver Texas Instruments SM72295 1

69 U8 Digital Controller Texas Instruments SM72442 1

70 U9 5-Pin Microprocessor Reset Circuits Texas Instruments SM72240 1

71 U11, U12 Dual Micro-Power Rail-to-Rail Input CMOS Texas Instruments SM72375 2

Comparator with Open Drain Output

72 L1 Inductor 2 uH EFD-30 core PULSE PA2965-203NL 1

18 AN-2121 SolarMagic™ SM3320-BATT-EV Charge Controller Reference Design SNOSB76C–December 2010–Revised May 2013

Submit Documentation Feedback

www.ti.com

Charge Controller System Schematic

17 Charge Controller System Schematic

Figure 20. Charge Controller System Schematic, Part 1

SNOSB76C–December 2010–Revised May 2013 AN-2121 SolarMagic™ SM3320-BATT-EV Charge Controller Reference

Design

Charge Controller System Schematic

www.ti.com

Figure 21. Charge Controller System Schematic, Part 2

20 AN-2121 SolarMagic™ SM3320-BATT-EV Charge Controller Reference Design SNOSB76C–December 2010–Revised May 2013

Submit Documentation Feedback

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