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Application Note 1941
ISL8203MEVAL2Z Evaluation Board User Guide
The ISL8203M is a complete, dual step-down power module
with integrated PWM controller, synchronous switching
MOSFETs, inductors, and passives. The ISL8203M is rated for
dual 3A output current or 6A current sharing operation with an
input range of 2.85V to 6V. The two channels are 180°
out-of-phase for input RMS current and EMI reduction.
The simplicity of the ISL8203M is its off the shelf, unassisted
implementation. It is easy to apply this complete step-down
power module to any low voltage low power application.
The ISL8203MEVAL2Z evaluation board is designed to
demonstrate the performance of the ISL8203M. The board is
by default set up to demonstrate two 3A outputs
independently, and can also be easily set up for current
sharing 6A by changing placeholder resistors.
Related Resources
• VOUT adjustable 0.8V to 5V
• Peak current limiting and hiccup mode short circuit
protection
• Over-temperature protection
• Internal digital soft-start
• External synchronization up to 4MHz
• Flexibility to operate in dual output mode or parallel single
output mode with simple resistor changes.
• Mechanical switch for enable and power-good LED indicator
• Connectors, test points, and jumpers for easy probing
• 0V to 6V power supply with at least 5A source current
capability
Ordering Information
• Electronic load capable of sinking current up to 6A
DESCRIPTION
ISL8203MEVAL2Z
• VIN range 2.85V to 6V
Recommended Equipment
ISL8203M datasheet
PART NUMBER
Key Features
• Digital multimeters (DMMs)
ISL8203M Dual 3A/Single 6A
Power Module Evaluation Board
• 100MHz quad-trace oscilloscope
LOAD2
(0A TO 3A)
-
+
(2.85V TO 6V)
LOAD1
(0A TO 3A)
FIGURE 1. ISL8203MEVAL2Z BOARD PHOTO
August 29, 2014
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1
CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.
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Application Note 1941
Functional Description
The ISL8203M’s two 3A outputs may be used independently or
combined to deliver a single 6A output. Each of the two channels
employs the current mode pulse width modulation scheme for
fast transient response and pulse-by-pulse current limiting. The
two channels each operate at a fixed 1MHz switching frequency,
and are 180° out-of-phase, which reduces the input and output
noise. The ISL8203M offers internal digital soft-start, external
synchronization, overcurrent protection, and over-temperature
protection. For further information, please refer to the ISL8203M
datasheet.
Quick Start
8. Measure the output voltage at test points VOUT1 or VOUT2
and GND test point.
Programming the Output Voltage
The ISL8203MEVAL2Z evaluation board has several preset
output voltages, 1.0V, 1.2V, 1.5V, 2.5V, and 3.3V, which can be
selected in J1 and J2 jumper. To program for other output
voltages in the range from 0.8V to 5V, the user can use a
feedback resistor divider based on Equation 1.
R FB – TOP 

V OUT =  1 + -------------------------------------------------  0.8V
R

FB – BOTTOM
(EQ. 1)
The top feedback resistor RFB-TOP is typically 100kΩ. In the
ISL8203MEVAL2Z evaluation board, the top feedback resistor is
R12 (for channel 1) and R11 (for channel 2).
Dual Output Mode
1. Make sure the placeholder resistors are set for dual output
mode according to Table 1 (The ISL8203MEVAL2Z evaluation
board is by default set up in dual output mode).
2. Set the ENABLE switches S1 and S2 to “OFF” positions.
3. Select the output voltage for channel 1 by making a selection
on jumper J1. Similarly, select the output voltage for
channel 2 by making a selection on jumper J2.
4. Connect the positive of a power supply to VIN1 and VIN2
connectors, and the negative of the power supply to one or
both of the GND connectors. Make sure the power supply is
not enabled when making connections.
Setting Parallel Single Output Mode
The ISL8203MEVAL2Z evaluation board is by default set up in
dual output mode with two independent outputs, but it can also
be easily modified to parallel single output circuit by changing
several placeholder resistors. Table 1 shows the placeholder sets
to program the default dual output mode and the parallel single
output mode.
TABLE 1. PLACEHOLDER SETS TO PROGRAM DUAL OUTPUT MODE
AND PARALLEL SINGLE OUTPUT MODE
PLACEHOLDER
DUAL OUTPUT
MODE
PARALLEL SINGLE OUTPUT
MODE
6. Turn ENABLE switch S1 to “ON” position to enable channel 1
and switch S2 to “on” position to enable channel 2. Each
ENABLE switch can control channel 1 and channel 2
independently.
R13
Open
0Ω
R24
0Ω
Open
R25
0Ω
Open
7. The power-good LED should glow in green if both channel 1
and channel 2 are operating properly. If either one channel is
disabled or not operating properly, the LED will glow in red.
R28
Open
0Ω
R18, R19
Open
0Ω (SMD, size 2010) or copper
strips
5. Turn the power supply on.
8. Measure the channel 1 (or channel 2) output voltage at test
points VOUT1 (or VOUT2) test point and adjacent GND test
point.
Parallel Single Output Mode
1. Set the placeholder resistors for parallel single output mode
according to Table 1.
2. Set the ENABLE switches S1 and S2 to “OFF” positions.
3. Select the output voltage using either one of the jumpers J1
and J2, but do not use both J1 and J2 at the same time.
External Synchronization
The frequency of operation can be synchronized up to 4MHz by
an external signal applied to the SYNC pin. The switching
frequency per channel is half of the external signal’s frequency
applied to the SYNC pin. The maximum external signal frequency
is limited by the SW minimum on time (140ns MAX)
requirement, which can be calculated as shown in Equation 2.
V OUT
1
1
----  f
= f SW – MAX = ------------------  -----------------------V IN 140ns
2 SYNC – MAX
(EQ. 2)
4. Connect the positive of a power supply to VIN1 and VIN2
connectors, and the negative of the power supply to one or
both of the GND connectors. Make sure the power supply is
not enabled when making connections.
where:
5. Turn the power supply on.
• fSW-MAX is the maximum switching frequency per channel
• fSYNC-MAX is the maximum external signal frequency
6. Turn both ENABLE switches S1 and S2 to “on” positions, in any
order. Both ENABLE switches need to be in the “on” position
in order to enable the output.
7. The power-good LED should glow in green if the output is
operating properly. If module is disabled or not operating
properly, the LED will glow in red.
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Application Note 1941
Evaluation Board Information
The ISL8203MEVAL2Z evaluation board is a 3X3 in four-layer FR-4
board with 2oz. copper on the top and bottom layers and 1oz.
copper on all internal layers. The board can be used as a dual 3A
reference design. Refer to “Layout” on page 6. The board is designed
with mechanical switches for ENABLE, power-good LED indicators,
several connectors, test points, and jumpers, which make testing
the board easy.
Thermal Considerations and
Current Derating
Board layout is very critical in order to make the module operate
safely and deliver maximum allowable power. In order for the
board to operate properly in the high ambient temperature
environments and carry full load currents, the board layout needs
to be carefully designed to maximize thermal performance. To
achieve this, select enough trace width, copper weight, and
proper connectors.
The ISL8203MEVAL2Z evaluation board is capable of full load
current (dual channel 3A or single 6A) at room temperature with
plenty of safety margin for junction temperature. However, if the
board is to operate at elevated ambient temperatures, then the
available output current may need to be derated. Refer to the
derated current curves in the ISL8203M datasheet to determine
the maximum output current the evaluation board can supply.
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SYNC
R16
SYNCA
VIN_1A
1K
VIN1
VIN1
21
VOUT2
NC
ISL8203MIRZ
FB2
C5
22UF
22UF
COUT3
22UF
COUT2
COUT1
0
UNNAMED_1_SMCAP_I690_A
5
E
VOUT1
3
5
7
9
6
8
10
R19
DNP
R18
VOUT2
UNNAMED_1_CONN10_I580_IN2
UNNAMED_1_CONN10_I580_IN4
UNNAMED_1_CONN10_I580_IN6
UNNAMED_1_CONN10_I580_IN8
UNNAMED_1_CONN10_I580_IN10
2
4
6
8
10
0
4
1
3
5
7
9
1
J2
9
UNNAMED_1_CONN10_I579_IN2
UNNAMED_1_CONN10_I579_IN4
UNNAMED_1_CONN10_I579_IN6
UNNAMED_1_CONN10_I579_IN8
UNNAMED_1_CONN10_I579_IN10
2
4
6
8
10
2
2
7
10
J1
1
SW2A
D
DNP
DNP
8
SW2
R28
SW1A
1
3
5
7
9
SW1
5
8
3
SGND
SW2
1800PF
23
PGND
NC
4
16
NC
PGND
270PF
C3
R25
100K
FB2
14
Application Note 1941
SW1
15
R24
VOUT2
R11
13
E
VOUT_2A
VOUT2
7
6
30.1K
COMP
UNNAMED_1_SMCAP_I683_A
D
GND_2A
1800PF
UNNAMED_1_ISL8203M_I692_17
17
9
C2
R14
0.022UF
E
SS
GND_2B
0
UNNAMED_1_SMCAP_I689_A
E
EN1
PG2
FB1
GND_1B
22UF
1
UNNAMED_1_ISL8203M_I692_1
U1
VIN2
C4
18
FB1
R29
100K
19
22UF
12
PG1
6
COUT6
PG2
NC
COUT5
22
VOUT1
EN2
4
R13
10
EN1
CIN4
CIN3
100UF
20
VIN2
VIN2
22UF
4
VIN2
PG1
DNP
E
VIN_2A
VIN1
GND2
GND_1A
22UF
11
GND1
VOUT1
R12
COUT4
3
EN2
VOUT1
SYNC
2
EN2
VDD
22UF
CIN1
CIN2
VOUT_1A
100UF
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ISL8203MEVAL2Z Schematic
GND
VIN1
VIN1
0
R27
32.4K
R10
113K
R8
402K
R6
32.4K
R5
R3
R1
UNDER MODULE
113K
D
402K
E
SHORT SGND TO PGND
3.32K
47.5K
R9
200K
R7
47.5K
R4
R2
R26
100K
UNNAMED_1_SMRES_I523_B
200K
VIN2
R20
UNNAMED_1_SMRES_I524_B
0
1
UNNAMED_1_GTSERIES_I648_NC
2
S2
3
R1 402K 1V
1
4
D
R6 402K 1V
R2 200K 1.2V
R7 200K 1.2V
R3 113K 1.5V
R8 113K 1.5V
R4 47.5K 2.5V
R9 47.5K 2.5V
R5 32.4K 3.3V
R10 32.4K 3.3V
3
1
0
3
UNNAMED_1_NCHANNEL_I471_D
R23
UNNAMED_1_NCHANNEL_I471_G
Q1
PG2
2
E
2N7002-7-F
PG2A
S1
D
2
PG1
R22
2
GRN
RED
LED1
PG1A
3
1
3.32K
EN2
EN1
R21
DRAWN BY:
DATE:
TIM KLEMANN
ENGINEER:
RELEASED BY:
DATE:
UPDATED BY:
DATE:
DATE:
JIAN YIN
03/27/2014
TITLE:
ISL8203M DUAL 3A /
MARK COSTELLO
SINGLE 6A EVALUATION
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August 29, 2014
Application Note 1941
Bill of Materials
MANUFACTURER’S
PART NUMBER
C0603X7R500-223KNE
C0603C271J5GACTU
REFERENCE
DESIGNATOR
QTY
MANUFACTURER
C2
1
VENKEL
DESCRIPTION
CAP, SMD, 0603, 0.022µF, 50V, 10%, X7R, ROHS
C3
1
KEMET
C4, C5
2
MURATA
CAP, SMD, 0603, 1800pF, 50V, 10%, X7R, ROHS
CIN1, CIN3
2
TAIYO YUDEN
CAP, SMD, 1210, 100µF, 16V, 20%, X5R, ROHS
GRM31CR61C226KE15L
CIN2, CIN4, COUT1-COUT6
8
MURATA
CAP, SMD, 1206, 22µF, 16V, 10%, X5R, ROHS
108-0740-001
GND1, GND2, VIN1, VIN2,
VOUT1, VOUT2
6
JOHNSON
COMPONENTS
CONN-JACK, BANANA-SS-SDRLESS, VERTICAL, ROHS
67996-272HLF
J1, J2
2
BERG/FCI
CONN-HEADER, 2X5, BRKAWY-2X36, 2.54mm, ROHS
SSL-LXA3025IGC-TR
LED1
1
LUMEX
LED, SMD, 3x2.5mm, 4P, RED/GREEN, 12/20MCD, 2V
Q1
1
DIODES, INC.
TRANSISTOR, N-CHANNEL, 3LD, SOT-23, 60V, 115mA,
ROHS
ERJ-3EKF4023V
R1, R6
2
PANASONIC
RES, SMD, 0603, 402k, 1/16W,1%, TF, ROHS
CRCW0603200KFKEA
R2, R7
2
VISHAY/DALE
RES, SMD, 0603, 200k, 1/10W, 1%, TF, ROHS
MCR03EZPFX1133
R3, R8
2
ROHM
RES, SMD, 0603, 113k, 1/10W, 1%, TF, ROHS
CR0603-10W-4752FT
R4, R9
2
VENKEL
RES, SMD, 0603, 47.5k, 1/10W, 1%, TF, ROHS
ERJ-3EKF3242V
R5, R10
2
PANASONIC
RES, SMD, 0603, 32.4k, 1/10W, 1%, TF, ROHS
R11, R12, R26
3
VENKEL
R13, R28
0
GRM39X7R182K050AQ
EMK325ABJ107MM-T
2N7002-7-F
CR0603-10W-1003FT
R14
1
VENKEL
ERJ-3EKF1001V
R16
1
PANASONIC
R18, R19
0
CR0603-10W-000T
GT13MCBE
ISL8203MIRZ
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RES, SMD, 0603, 30.1k, 1/10W, 1%, TF, ROHS
RES, SMD, 0603, 1k, 1/10W, 1%, TF, ROHS
RES, SMD, 2010, DNP, DNP, DNP, TF, ROHS
R20, R21
2
YAGEO
RES, SMD, 0603, 3.32k, 1/10W, 1%, TF, ROHS
R22, R23, R24, R25, R27,
R29
6
VENKEL
RES, SMD, 0603, 0Ω, 1/10W, TF, ROHS
S1, S2
2
C&K
COMPONENTS
SWITCH-TOGGLE, THRU-HOLE, 5PIN, SPDT, 3POS,
ON-OFF-ON, ROHS
INTERSIL
IC-6A POWER SUPPLY MODULE, 23P, QFN, ROHS
U1
5
RES, SMD, 0603, 100k, 1/10W, 1%, TF, ROHS
RESISTOR, SMD, 0603, 0.1%, MF, DNP-PLACE HOLDER
CR0603-10W-3012FT
RC0603FR-073K32L
CAP, SMD, 0603, 270pF, 50V, 5%, C0G, ROHS
AN1941.1
August 29, 2014
Application Note 1941
Board Layout
FIGURE 2. SILK SCREEN TOP LAYER
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Application Note 1941
Board Layout
FIGURE 3. TOP LAYER
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Application Note 1941
Board Layout
FIGURE 4. LAYER 2
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Application Note 1941
Board Layout
FIGURE 5. LAYER 3
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Application Note 1941
Board Layout
FIGURE 6. BOTTOM LAYER
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Application Note 1941
Board Layout
FIGURE 7. SILK SCREEN BOTTOM
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Application Note 1941
ISL8203MEVAL2Z Performance Data
The following data was acquired using a ISL8203MEVAL2Z
100
100
95
95
90
90
EFFICIENCY (%)
EFFICIENCY (%)
evaluation board at +25°C ambient and free air 0LFM.
85
80
VOUT = 2.5V
75
VOUT = 1.2V
VOUT = 1.5V
70
85
80
0
0.5
1.0
1.5
2.0
2.5
60
3.0
0
1
2
3
4
5
6
LOAD CURRENT (A)
LOAD CURRENT (A)
FIGURE 8. EFFICIENCY, SINGLE CHANNEL, V IN = 5V
FIGURE 9. EFFICIENCY, PARALLEL SINGLE OUTPUT, V IN = 5V
100
95
95
90
90
EFFICIENCY (%)
EFFICIENCY (%)
VOUT = 1.2V
65
100
85
80
VOUT = 1.5V
VOUT = 1.2V
75
VOUT = 2.5V
70
85
VOUT = 1.5V
80
75
VOUT = 1V
VOUT = 2.5V
70
VOUT = 1V
65
60
VOUT = 2.5V
VOUT = 1V
70
VOUT = 1V
65
60
VOUT = 1.5V
75
0
0.5
1.0
1.5
2.0
2.5
3.0
VOUT = 1.2V
65
60
0
1
2
3
4
5
6
LOAD CURRENT (A)
LOAD CURRENT (A)
FIGURE 10. EFFICIENCY, SINGLE CHANNEL, V IN = 3.3V
FIGURE 11. EFFICIENCY, PARALLEL SINGLE OUTPUT, V IN = 3.3V
50mV/DIV
20mV/DIV
2µs/DIV
FIGURE 12. OUTPUT VOLTAGE RIPPLE AT VIN = 5V, VOUT = 1.5V,
PARALLEL SINGLE OUTPUT, IOUT = 6A, COUT = 6x22µF
CERAMIC CAPACITORS
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12
50µs/DIV
FIGURE 13. LOAD TRANSIENT RESPONSE AT VIN = 5V, VOUT = 1.2V,
PARALLEL SINGLE OUTPUT, 0A TO 3A LOAD STEP,
COUT = 6x22µF, LOAD CURRENT SLEW RATE: 1A/µs
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Application Note 1941
ISL8203MEVAL2Z Performance Data (Continued)
The following data was acquired using a
ISL8203MEVAL2Z evaluation board at +25°C ambient and free air 0LFM.
FIGURE 14. THERMAL IMAGE AT VIN = 5V, VOUT = 1.5V, I OUT = 6A, PARALLEL SINGLE OUTPUT, TA = +25°C, FREE AIR 0LFM
Intersil Corporation reserves the right to make changes in circuit design, software and/or specifications at any time without notice. Accordingly, the reader is
cautioned to verify that the Application Note or Technical Brief is current before proceeding.
For information regarding Intersil Corporation and its products, see www.intersil.com
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