User’s Manual
ISL8225MEVAL3Z
User’s Manual: Evaluation Board
Industrial Analog and Power
All information contained in these materials, including products and product specifications,
represents information on the product at the time of publication and is subject to change by
Renesas Electronics Corp. without notice. Please review the latest information published by
Renesas Electronics Corp. through various means, including the Renesas Electronics Corp.
website (http://www.renesas.com).
Renesas Electronics Corporation
www.renesas.com
Rev.2.00 Jun.10.19
User’s Manual
ISL8225MEVAL3Z
Evaluation Board
The ISL8225M is a complete, dual step-down switching mode DC/DC module. The dual outputs can easily be
paralleled for single-output, high-current use. It is easy to apply this high-power, current-sharing DC/DC power
module to power-hungry datacom, telecom, and FPGA applications. All that is needed in order to have a
complete, 30A design ready for use are the ISL8225M, a few passive components, and VOUT setting resistors.
The ease of use virtually eliminates design and manufacturing risks while dramatically improving time to market.
The simplicity of the ISL8225M is its off-the-shelf, unassisted implementation. The module structure allows for
higher power density and better efficiency than competing solutions. The current sharing in multiphase operation
greatly reduces ripple currents, BOM costs, and complexity.
The ISL8225MEVAL3Z evaluation board enables a single output by paralleling two phases to deliver 30A
continuous load current. The ISL8225M supports input voltages from 4.5V to 20V and output voltages from 0.6V
to 7.5V. With the single resistor modification, the output voltage can be easily adjusted to different voltages.
Key Features
• Up to 100W output
• Single 30A output
• 4.5V to 20V input range
• 0.6V to 7.5V output range
• 1.5% output voltage accuracy
• Up to 95% conversion efficiency
• Lower output ripple and input ripple due to 180° phase shift
Specifications
This board is configured and optimized for the following operating conditions:
• VIN = 4.5V to 20V, VO = 1.2V
• IO = 30A
• fSW = 500kHz
• 180° phase shift between phases
Ordering Information
Part Number
ISL8225MEVAL3Z
Description
30A, Single Output Evaluation Board
Related Literature
For a full list of related documents, visit our website:
• ISL8225M device page
Related Resources
• Evaluation Board Video
AN1790 Rev.2.00
Jun.10.19
Page 2 of 13
ISL8225MEVAL3Z
+
VIN V
-
4.5V to 20V
+
LOAD
(0A~30A)
-
+
V VOUT
-
Figure 1. ISL8225MEVAL3Z Board
AN1790 Rev.2.00
Jun.10.19
Page 3 of 13
ISL8225MEVAL3Z
1.
1.1
1. Functional Description
Functional Description
Recommended Equipment
• 0V to 20V power supply with at least 10A source current capability
• Electronic load capable of sinking current up to 30A
• Digital Multimeters (DMMs)
• 100MHz quad-trace oscilloscope
1.2
High Output Voltage Operation
The evaluation board is designed for output voltage below 5.5V. For output voltage higher than 6V, capacitors with
10V rating must be used for C10 to C14. See the “ISL8225M Design Guide Matrix” table in the ISL8225M
datasheet for selections of output capacitors, input capacitors, and switching frequency. The maximum load
capability is 20A for 6.5V output and 14A for 7.5V output.
1.3
Quick Start
The inputs are J1 (VIN) and J2 (GND). The outputs are J3 (VOUT) and J4 (GND). See Figure 1 on page 3 for
connections.
1. Connect a power supply capable of sourcing at least 10A to the ISL8225MEVAL3Z’s input (VIN J1 and GND
J2), with a voltage between 4.5V to 20V. Connect an electronic load or the device to be powered to the board’s
output (VOUT J3 and GND J4). All connections, especially the low voltage, high current VOUT lines, should be
able to carry the desired load current and should be made as short as possible.
2. Turn on the power supply. Measure the output voltage, VOUT, which should be at 1.2V if the board is working
properly.
3. The ISL8225MEVAL3Z is manufactured with a default VOUT value of 1.2V. If different output voltages are
needed, board resistors can be exchanged to provide the required VOUT. See the table printed on the
backside of the evaluation board or Table 1 for RVSET resistor values, which can be used to produce different
output voltages.
For 12V VIN, and VOUT more than 1.5V, the switching frequency needs to be adjusted, as shown in Table 1; no
frequency adjustments are necessary for VOUT below 1.5V. For 5V VIN, the frequency does not need to be
adjusted and the module default frequency can be used at any allowed VOUT. If the output voltage is set to more
than 1.8V, the output current needs to be derated to allow for safe operation at elevated ambient temperatures.
See the derating curves in the ISL8225M datasheet.
For VIN < 5.5V, tie VIN directly to VCC for best efficiency. Also, Renesas recommends that the EN/FF voltage is
over 1.5V to achieve better stability.
Table 1.
Resistance Setting for Different Output Voltages and Operating Frequency (R3 = 1k)
VOUT (V)
RVSET (Ω)
Frequency (kHz)
RFSET (Ω) (VIN = 12V)
1.0
1500
Default
Default
1.2
Default
Default
Default
1.5
665
Default
Default
2.5
316
650
249k
3.3
221
800
124k
5.0
137
950
82.5k
5.5
121
950
82.5k
6.5
102
750
147k
7.5
86.6
750
147k
AN1790 Rev.2.00
Jun.10.19
Page 4 of 13
ISL8225MEVAL3Z
2.
2. PCB Layout Guidelines
PCB Layout Guidelines
The evaluation board size is 3 inch x 3 inch. It is a 4-layer board, containing 2-ounce copper on the top and
bottom layers and 1-ounce copper on all internal layers. The board can be used as a 30A reference design. See
“Layout” on page 8. The board is made up of FR4 material and all components, including the solder attachment,
are Pb-free.
2.1
Thermal Considerations and Current Derating
For high current applications, board layout is very critical to make the module operate safely and deliver maximum
allowable power. To carry large currents, the board layout needs to be carefully designed to maximize thermal
performance. To achieve this, select enough trace width, copper weight, and the proper connectors.
The ISL8225MEVAL3Z is designed for running 30A at 1.2V at room temperature without additional cooling
systems needed. However, if the output voltage is increased or the board is operated at elevated temperatures,
then the available current is derated. See the derated current curves in the ISL8225M datasheet to determine the
output current available.
For layout of designs using the ISL8225M, the thermal performance can be improved by adhering to the following
design tips:
• Use the top and bottom layers to carry the large current. VOUT1, VOUT2, Phase 1, Phase 2, PGND, VIN1, and
VIN2 should have large, solid planes. Place enough thermal vias to connect the power planes in different layers
under and around the module.
• The Phase 1 and Phase 2 pads are switching nodes that generate switching noise. Keep these pads under the
module. For noise-sensitive applications, Renesas recommends keeping the phase pads only on the top and
inner layers of the PCB; do not place the phase pads exposed to the outside on the bottom layer of the PCB. To
improve the thermal performance, the phase pads can be extended in the inner layer, as shown in Phase 1 and
Phase 2 pads on Layer 3 (see Figure 6) for this 30A evaluation board. Make sure that Layer 2 and Layer 4 have
the GND layers cover the extended areas of phase pads at Layer 3 to avoid noise coupling.
• To avoid noise coupling, Renesas recommends adding 470pF capacitors on all the COMP pins of each module
for multiple module operations.
• If the ambient temperature is high or the board space is limited, airflow is needed to dissipate more heat from
the modules. A heat sink can also be applied to the top side of the module to further improve the thermal
performance (heat sink recommendation: Aavid Thermalloy, part number 375424B00034G, www.aavid.com).
AN1790 Rev.2.00
Jun.10.19
Page 5 of 13
ISL8225MEVAL3Z Board Schematic
VCC
ISL8225M
SYNC
TP4
C6
SINGLE OUTPUT DUAL PHASE 30A
DNP
RFSET
TP3
ISL8225MEVAL3Z
4.7UF
E
TP1
4.5V TO 20V
S1
C16
VIN
470PF
AN1790 Rev.2.00
Jun.10.19
2.2
J1
SGND
S1
2
3
4
5
6
7
8
9
C5
22UF
C4
22UF
C3
22UF
C2
22UF
C1
470UF
TP5
E
VCC
VSEN2-
PHASE2
10
TP2
VSEN2+
M1
R4
1
3.3K
PHASE2
IN
COMP2
MODE
VMON2
VIN2
SYNC
J2
SGND
PGND
VCC
GND
PGOOD
26
1.2V @ 30A
TP6
TP10
25
VOUT2
C15
330UF
C14
100UF
C13
100UF
C12
100UF
1K
21
1K
GND
20
19
18
17
16
15
14
R3
COMP1
VMON1
13
OPEN
22
RVSET
ISHARE
VIN1
CLKOUT
PGND
E
EN/FF1
S1
EN/FF2
SGND
23
C11
VSEN1-
J3
C9
DNP
VSEN1+
VOUT
24
47UF
12
PHASE1
PGOOD
VOUT1
EGND
ISL8225MIRZ
N/C
PHASE1
GND_S1
11
C10
E
J4
EN
TP7
470PF
6.04K
R1
C8
E
E
S1
2.05K
R2
C7
1000PF
TP8
DRAWN BY:
SGND
TP9
TIM KLEMANN
DATE:
RELEASED BY:
DATE:
UPDATED BY:
DATE:
Figure 2. ISL8225MEVAL3Z Board Schematic
TITLE:
JIAN YIN
DATE:
ISL8225M
EVALUATION BOARD
Page 6 of 13
2. PCB Layout Guidelines
S1
ENGINEER:
10/18/2012
Bill of Materials
Part Number
Ref Des
Qty.
Value
Tol.
Voltage
108-0740-001
J1-J4
4
10TPB330M
C15
1
TP1-TP10
10
C1
1
470µF
20%
25V
C2-C5
4
22µF
10%
C7
1
C8, C16
H1045-00475-6R3V10-T
Power
Package
Type
Manufacturer
Description
BAN-JACK
Johnson
Components
Standard type banana jack
CAP_7343_149
SANYOPOSCAP
Standard solid electrolytic chip tantalum SMD
capacitor
MTP500X
Keystone
Miniature white test point 0.100 pad 0.040 Thole
SMD
CAPAE_393X402
Panasonic
Aluminum electrolytic S series type V capacitor
(RoHS compliant)
25V
1210
CAP_1210
Murata
Ceramic chip capacitor
1000pF 10%
50V
603
CAP_0603
Generic
Multilayer capacitor
2
470pF
10%
50V
603
CAP_0603
Generic
Multilayer capacitor
C6
1
4.7µF
10%
6.3V
603
CAP_0603
Generic
Multilayer capacitor
H1045-OPEN
C9
1
OPEN
5%
OPEN
603
CAP_0603
Generic
Multilayer capacitor
H1046-00476-6R3V20-T
C10
1
47µF
20%
6.3V
805
CAP_0805
Generic
Multilayer capacitor
H1065-00107-6R3V20-T
C12-C14
3
100µF
20%
6.3V
1206
CAP_1206
Generic
Multilayer capacitor
C11
1
OPEN
5%
OPEN
1206
CAP_1206
Generic
Multilayer capacitor
RFSET
1
DNP
1%
DNP
603
RES_0603
Generic
Metal film chip resistor (do not populate)
R2
1
2.05kΩ
1%
1/10W
603
RES_0603
Generic
Thick filmchip resistor
H2511-01001-1/16W1
R3,
RVSET
2
1kΩ
1%
1/16W
603
RES_0603
Generic
Thick filmchip resistor
H2511-03301-1/16W5
R4
1
3.3kΩ
5%
1/16W
603
RES_0603
Generic
Thick filmchip resistor
H2511-06041-1/16W1
R1
1
6.04kΩ
1%
1/10W
603
RES_0603
Generic
Thick filmchip resistor
ISL8225MIRZ
M1
1
QFN
QFN26_670X670_ISL8225M
Renesas
Dual 15A DC/DC power module
5002
EEE1EA471P
GRM32ER71E226KE15L
H1045-00102-50V10-T
H1045-00471-50V10
H1065-OPEN
H2505-DNP-DNP-1
H2511-02051-1/10W1-T
CONN
Jedec Type
330µF
20%
10V
SMD
THOLE
Page 7 of 13
2. PCB Layout Guidelines
Note: Resistance accuracy of feedback resistor divider R1/R2 can affect the output accuracy. Please use high accuracy resistance (0.5% or 0.1%) to meet the output accuracy requirement.
ISL8225MEVAL3Z
AN1790 Rev.2.00
Jun.10.19
2.3
ISL8225MEVAL3Z
2.4
2. PCB Layout Guidelines
Layout
Figure 3. Top Components
Figure 4. Top Layer
Figure 5. Layer 2
Figure 6. Layer 3
AN1790 Rev.2.00
Jun.10.19
Page 8 of 13
ISL8225MEVAL3Z
Figure 7. Bottom Layer
AN1790 Rev.2.00
Jun.10.19
2. PCB Layout Guidelines
Figure 8. Bottom Components
Page 9 of 13
ISL8225MEVAL3Z
3.
3. ISL8225MEVAL3Z Efficiency Curves
ISL8225MEVAL3Z Efficiency Curves
Test conditions at +25°C and no air flow.
95
100
1.8VOUT
2.5VOUT
90
1.5VOUT
Efficiency (%)
Efficiency (%)
1.8VOUT
95
85
1.2VOUT
80
1VOUT
75
70
90
1.2VOUT
85
1.5VOUT
1VOUT
80
75
65
60
2.5VOUT
0
5
10
15
20
Load Current (A)
Figure 9. 12V Input
AN1790 Rev.2.00
Jun.10.19
25
30
70
0
5
10
15
20
25
30
Load Current (A)
Figure 10. 5V Input
Page 10 of 13
ISL8225MEVAL3Z
4.
4. Revision History
Revision History
Rev.
Date
2.00
Jun.10.19
AN1790 Rev.2.00
Jun.10.19
Description
Applied new formatting throughout document.
Replaced QR code with link to video on page 1.
Added Revision History section.
Page 11 of 13
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