EN6337QI/EN6347QI Evaluation Board User Guide
Nov 2010
Page 1 of 9
Enpirion EN6337QI/EN6347QI DC-DC Converter
w/Integrated Inductor Evaluation Board
Introduction
Thank you for choosing Enpirion, the source for ultra small foot print power converter
products! This evaluation board user guide applies to two products with identical
pinouts: The EN6337QI is a 3A device, and the EN6347QI is a 4A device. The term
EN63x7QI will refer to both products throughout this document. This evaluation board
user guide applies to the EN63x7−03 engineering devices. In addition to this document,
you will also need the latest device datasheet.
• The EN63x7QI features integrated inductor, power MOSFETS, controller, a bulk
of the compensation network, and protection circuitry against system faults. This
level of integration delivers a substantial reduction in footprint and parts count
over competing solutions. The evaluation board is optimized for engineering ease
of testing through programming options, clip leads, test points etc.
• The EN63x7QI features a customer programmable output voltage by means of a
resistor divider. The resistor divider allows the user to set the output voltage to
any value within the range 0.75V to (VIN-VDROPOUT). The evaluation board, as
shipped is populated with a 4 resistor divider option. The upper resistor is fixed
and has a phase lead capacitor in parallel. One of the 4 lower resistors is
selected with the jumper option for different output voltages to change VOUT,
retain the upper resistor and capacitor values and change only the lower resistor.
• This device has no over-voltage protection feature. We strongly recommend the
customer to ensure the feedback loop is truly closed before powering up the
device especially if the load can not withstand the input voltage.
• The input and output capacitors are X5R or X7R multi-layer ceramic chip
capacitors. The Soft-start capacitor is a small 15nF X7R MLCC. Pads are
available to have multiple input and output capacitors. This allows for evaluation
of performance over a wide range of input/output capacitor combinations.
• Clip-on terminals are provided for ENA, SS, POK, and LLM pins.
• Banana jacks are provided for VIN and VOUT power terminals. Several signal and
GND clip-on test points are also provided to measure VIN, VOUT, and GND nodes.
EN6337QI/EN6347QI Evaluation Board User Guide
Nov 2010
Page 2 of 9
• A jumper is provided for controlling the Enable signal. Enable may also be
controlled using an external switching source by removing the jumper and
applying the enable signal to the ENA clip-on terminal.
• A jumper is also provided to connect the POK pull-up resistor to the input supply.
This jumper is especially useful to measure the disable current and eliminates
having to subtract the current drawn by the POK resistor.
• A jumper is provided for controlling the LLM/SYNC pin. This pin can be high for
automatic LLM (light-load mode) operation. If it is pulled low, the part will be in
PWM mode only.
• Foot print is also provided for a SMA connector to LLM/SYNC input. A switching
input to this pin allows the device clock to be phase locked to an external signal.
This external clock synchronization allows for moving any offending beat
frequency to be moved out-of-band. A swept frequency applied to this pin results
in spread spectrum operation and reduces the peaks in the noise spectrum of
emitted EMI.
• The board comes with input decoupling and reverse polarity protection to guard
the device against common setup mishaps.
EN6337QI/EN6347QI Evaluation Board User Guide
Nov 2010
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Quick Start Guide
STEP 1: Set the “ENABLE” jumper to the Disable Position, as shown in Figure 1.
Figure 1: Show s POK, Enable, and LLM Jumpers. POK PWR jumper
as shown connects pull-up resistor to VIN. Enable jumper shown in
DISABLE position. LLM jumper as shown disables LLM operation.
STEP 2: Connect Power Supply to the input power connectors, VIN (+) and GND (-) as
indicated in Figure 1 and set the supply to the desired voltage. The device disable
current may be measured in this configuration.
CAUTION: be mindful of the polarity. Even though the evaluation board comes
with reverse polarity protection diodes, it may not protect the device under all
conditions.
STEP 3: Connect the load to the output connectors VOUT (+) and GND (-), as
indicated in Figure 1.
STEP 4: Select the output voltage setting jumper. Figure 2 shows what output voltages
are achieved by selecting each jumper position. Populat ing multiple jumper positions
will allow you to select higher output voltages. You can populate up to all four jumper
positions for the highest VOUT of approximately 3.73V with the resistors populated on the
board.
Figure 2: Output Voltage selection jumpers
Jumper shown selects 1.55V output
(Jumper positions from left to right are: 2.25V, 1.55V, 1.2V and 1.0V)
STEP 5: Set the POK PWR and LLM jumpers to desired positions (see Figure 1). You
should disable POK when measuring low value input currents.
STEP 6: Apply VIN to the board and move the ENA jumper to the enabled position. The
EN63x7QI is now powered up! Various measurements such as efficiency, line and load
regulation, input / output ripple, load transient, drop-out voltage measurements may be
EN6337QI/EN6347QI Evaluation Board User Guide
Nov 2010
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conducted at this point. The over current trip level, short circuit protection, under voltage
lock out thresholds, temperature coefficient of the output voltage may also be measured
in this configuration.
CAUTION: The maximum allowable VIN for this version of devices is 6.6V.
STEP 6A: Power Up/Down Behavior – Remove ENA jumper and connect a pulse
generator (output disabled) signal to the clip-on test point below ENA and Ground. Set
the pulse amplitude to swing from 0 to 2.5 volts. Set the pulse period to 10msec. and
duty cycle to 50%. Hook up oscilloscope probes to ENA, SS, POK and VOUT with clean
ground returns. Apply power to evaluation board. Enable pulse generator output.
Observe the SS capacitor and VOUT voltage ramps as ENA goes high and again as
ENA goes low. The device when powered down ramps down the output voltage in a
controlled manner before fully shutting down. The output voltage level when POK is
asserted /de-asserted as the device is powered up / down may be observed as well as
the clean output voltage ramp and POK signals.
STEP 7: External Clock Synchronization / Spread Spectrum Modes: In order to
activate this mode, it may be necessary to a solder a SMA connector at J8. Alternately
the input clock signal leads may be directly soldered to the through holes of J8 as
shown below.
GND
Ext. Clock
Figure 3: SMA Connector for External Clock Input
Power down the device. Move ENA into disable position. Connect the clock signal as
just indicated. The clock signal should be clean and have a frequency in the range of
the nominal frequency ±15%; amplitude 0 to 2.5 volts with a duty cycle between 20 and
80%. With SYNC signal disabled, power up the device and move ENA jumper to
Enabled position. The device is now powered up and outputting the desired voltage.
The device is switching at its free running frequency. The switching waveform may be
observed between test points SW and GND. Now enabling the SYNC signal will
automatically phase lock the internal switching frequency to the externally applied
frequency as long as the external clock parameters are within the specified range. To
observe phase-lock connect oscilloscope probes to the input clock as well as to the SW
test point. Phase lock range can be determined by sweeping the external clock
frequency up / down until the device just goes out of lock at the two extremes of its
range.
EN6337QI/EN6347QI Evaluation Board User Guide
Nov 2010
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For spread spectrum operation the input clock frequency may be swept between two
frequencies that are within the lock range. The sweep (jitter) repetition rate should be
limited to 10 kHz. The radiated EMI spectrum may be now measured in various states –
free running, phase locked to a fixed frequency and spread spectrum. Before measuring
radiated EMI, place a 10uF/0805, X7R capacitor at the input and output edges of the
PCB (footprint already provided on the board), and connect the input power and the
load to the board at or near these capacitors. The added capacitor at the input edge is
for high-frequency decoupling of the input cables. The one added at the output edge is
meant to represent a typical load decoupling capacitor.
Figure 4: Evaluation Board Layout Assembly Layer
EN6337QI/EN6347QI Evaluation Board User Guide
Nov 2010
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U1
EN63x7QI
NC(SW)1
1
NC(SW)2
2
NC3
3
NC4
4
VOUT
5
VOUT
6
VOUT
7
VOUT
8
VOUT
9
VOUT
10
VOUT
11
NC(SW)12
12
PGND
13
PGND
14
PGND
15
PGND
16
PGND
17
PGND
18
PVIN
19
BGND 25
VDDB 24
NC23 23
NC22 22
PVIN 21
PVIN 20
NC(SW)38 38
NC(SW)37 37
NC(SW)36 36
NC(SW)35 35
NC(SW)34 34
AVIN 33
AGND 32
VFB 31
SS 30
RLLM 29
POK 28
ENABLE 27
LLM/SYNC 26
C2 C6
C7C3
R2
TP17
R3
R1
TP5
R5
TP15
R7
J9
1
3
5
2
4
6
87
RLLM
R8
C10
R6
J2
1
2
J3
1
2
TP7 TP6
C11
R4
R9
CW -->
R10
1 3
2
J1
1
2
3
J10
1
2
3
C12
J8
TP18
TP19
C9 TP14
TP4
TP13
TP21
FB1
C13
U2
6.5V D1
+
C1 J13
1
2
J4
J6
LLM
PVIN
PVIN
TP1
TP2
J11
1
2
J12
1
2
J14
1
2
J7 J5
SS
ENA
POK
GND
VIN
PGND
VOUT
SYNC
ENAPOK
VIN
J15
1
2
3
TP12
TP16
TP3 TP20
TP8
TP10
TP9
TP11
0805
0805
0805
0805
0805
0805
0805
1206/0805
0402
0402
0805
0805
0805
0805
0805
1206/0805
1206/0805
1206/0805
TP26
Vout programming resistors:
R2 = 200kΩ
R7 = 100kΩ for VOUT = 2.25V
R5 = 187kΩ for VOUT = 1.55V
R1 = 332kΩ for VOUT = 1.20V
R3 = 604kΩ for VOUT = 1.00V
TP25
Figure 5: EN63x7 Evaluation Board Schematic
EN6337QI/EN6347QI Evaluation Board User Guide
Nov 2010
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Test Recommendations
Recommendations
To guarantee measurement accuracy, the following precautions should be observed:
1. Make all input and output voltage measurements at the board using the test
points provided (TP8 to TP11). This will eliminate voltage drop across the line
and load cables that can produce false readings.
2. Measure input and output current with series ammeters or accurate shunt
resistors. This is especially important when measuring efficiency.
3. Use a low-loop-inductance scope probe tip shown below to measure
switching signals and input / output ripple to avoid noise coupling into the
probe ground lead. Input ripple, output ripple, and load transient deviation are
best measured near the respective input / output capacitors. For more
accurate ripple measurement, please see Enpirion App Note regarding this
subject.
4. The board includes a pull-up resistor for the POK signal and ready to monitor
the power OK status at clip lead marked POK.
5. A 15nF soft-start capacitor is populated on the board for ~1msec soft-start
time.
6. The over-current protection circuit typically limits the maximum load current to
approximately 1.5X the rated value.
Input and Output Capacitors
Please refer to the BOM section for the value of input caps and output caps used on this
evaluation board, which is the result of combination for better performance and smaller
footprints.
NOTE: Capacitors must be X5R or X7R dielectric formulations to ensure adequate
capacitance over operating voltage and temperature ranges.
EN6337QI/EN6347QI Evaluation Board User Guide
Nov 2010
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Bill of Materials
Designator Qty Description
C1 1 CAP, SMT ELECTROLYTIC, 150UF, 20%, 10V
C2 1 CAP, CER 47UF 10V X5R 1206
C3, C13 2 CAP, 10UF 0805 X7R 10% 10V CERAMIC
C6 1 CAP, CER 22UF 10V X5R 1206
C10 1
EN6337QI Evaluation Board CAP, 15PF 50V CERM CHIP 0805 SMD
EN6347QI Evaluation Board CAP, CERM 10PF 5% 50V NP0 0805
C11 1 15000PF 10% 50V SMD 0805 X7R CERAMIC CHIP CAPACITOR
C7, C9, C12,
J2, J3, J8,
J11, J12, R6,
R10
10
NOT USED
D1 1 S2A DIODE
FB1 1
MULTILAYER SMD FERRITE BEAD 4000MA 0805 L=TYPICAL (NOT
GUARANTED)
J1, J10, J15 3 CONN, VERTICAL, 3 POSITION, SMT
J4-J7 4 BANANA JACK
J9 1 CONNECTOR HEADE R 8 POS .100" STR TIN
R1 1 RES 332K OHM 1/8W 1% 0805 SMD
R2 1 RES 200K OHM 1/8W 0.1% 0805 SMD
R3 1 RES 604K OHM 1/8W 1% 0805 SMD
R4 1 RES 100K OHM 1/8W 1% 0805 SMD
R5 1 RES 187K OHM 1/8W 1% 0805 SMD
R7 1 RES 100K OHM 1/8W 0.1% 0805 SMD
R8 1
EN6337QI RES 75.0K OHM 1/8W 1% 0805 SMD
EN6347QI RES 60.4K OHM 1/8W 0.1% 0805 SMD
R9 1 THICK FILM RESISITOR 0 OHM 1/8W 5% 0805 SMD
TP3, TP5,
TP8-TP12,
TP15-TP17
TP20, TP21,
TP25, TP26
14
TEST POINT SURFACE MOUNT
U1 1
EN6337QI Evaluation Board EN6337QI 3A GOOD TESTED
PRODUCT USING 6337-06 DIE- FIX
IN THE LLM FILTER LOGIC (GOLD
WIRE)
EN6347QI Evaluation Board EN6347QI 4A GOOD TESTED
PRODUCT USING 6347-06 DIE-
SOFT-SHORT FIX (COPPE R WIRE)
U2 1 TRANSIENT VOLTAGE SUPPRESSOR, 6.5V, BIDIRECTIONAL, SMT
EN6337QI/EN6347QI Evaluation Board User Guide
Nov 2010
Page 9 of 9
Contact Information
Enpirion, Inc.
Perryville III
53 Frontage Road - Suite 210
Hampton, NJ 08827 USA
Phone: +1-908-894-6000
Fax: +1.908-894-6090
www.enpirion.com
Enpirion reserves the right to make changes in circuit design and/or specifications at
any time without notice. Information furnished by Enpirion is believed to be accurate and
reliable. Enpirion assumes no responsibility for its use or for infringement of patents or
other third party rights, which may result from its use. Enpirion products are not
authorized for use in nuclear control systems, as critical components in life support
systems or equipment used in hazardous environments without the express written
authority from Enpirion.
