Intersil H2505-DNP-DNP-1 Isl8225meval3z 30a, single output evaluation board setup procedure Datasheet

Application Note 1790
ISL8225MEVAL3Z 30A, Single Output Evaluation Board
Setup Procedure
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.
Recommended Equipment
The ease of use virtually eliminates design and manufacturing
risks while dramatically improving time to market.
Quick Start
The simplicity of the ISL8225M is its off-the-shelf, unassisted
implementation. Patented module structure allows for higher
power density and better efficiency than competing solutions.
Patented current sharing in multi-phase 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 voltage from 4.5V
to 20V and the output voltage ranges from 0.6V to 6V. With the
single resistor modification, the output voltage can be easily
adjusted to different voltages.
Related Resources
See how-to
video at
intersil.com/
evid01
+
VIN
• 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
The inputs are J1 (VIN) and J2 (GND). The outputs are J3 (VOUT)
and J4 (GND). Refer to Figure 1 for connections.
1. Connect a power supply capable of sourcing at least 10A to
the input (VIN J1 and GND J2) of the ISL8225MEVAL3Z
evaluation board, with a voltage between 4.5V to 20V.
Connect an electronic load or the device to be powered to
the output (VOUT J3 and GND J4) of the board. 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 desired, board
resistors can be exchanged to provide the desired VOUT.
Please refer to the table printed on the backside of the
evaluation board or Table 1 on page 2 for RVSET resistor values,
which can be used to produce different output voltages.
+
+
V
-
LOAD
(0A~30A)
4.5V TO 20V
-
V
VOUT
-
FIGURE 1. ISL8225MEVAL3Z BOARD IMAGE
December 3, 2012
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1
CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.
Copyright Intersil Americas Inc. 2012. All Rights Reserved.
1-888-INTERSIL or 1-888-468-3774 | Intersil (and design) is a trademark owned by Intersil Corporation or one of its subsidiaries.
All other trademarks mentioned are the property of their respective owners.
Application Note 1790
For 12V VIN, and VOUT more than 1.5V, the switching frequency
will need 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 will need to be
derated to allow for safe operation at elevated ambient
temperatures. Please refer to the derating curves in the
ISL8225M datasheet.
For VIN < 5.5V, please tie VIN directly to VCC for best efficiency.
Also, it is preferred that the EN/FF voltage be over 1.5V in order
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
Evaluation Board Information
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. Refer to the “Layout” section beginning on
page 4. The board is made up of FR4 material and all
components, including the solder attachment, are lead-free.
This evaluation board is designed for running 30A @ 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. Refer to the derated current curves in the 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:
1. 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.
2. Phase 1 and Phase 2 pads are switching nodes that generate
switching noise. Keep these pads under the module. For
noise-sensitive applications, it is recommended to keep
phase pads only on the top and inner layers of the PCB; do not
place 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 (Figure 6) for this 30A evaluation
board. Make sure that layer 2 and layer 4 have the GND layers
to cover the extended areas of phase pads at layer 3 to avoid
noise coupling.
3. To avoid noise coupling, we recommend adding 470pF
capacitors on all COMP pins of each module for multiple
module operations.
4. 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).
Thermal Considerations and Current Derating
For high current applications, board layout is very critical in order
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.
2
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ISL8225MEVAL3Z Board Schematic
VCC
C6
S1
C16
VIN
470PF
J1
E
TP1
SINGLE OUTPUT DUAL PHASE 30A
DNP
RFSET
TP4
4.7UF
4.5V TO 20V
ISL8225M
SYNC
TP3
SGND
C5
22UF
C4
22UF
C3
22UF
C2
22UF
23
C15
330UF
C14
100UF
C13
100UF
RVSET
C12
1K
21
100UF
OPEN
R3
22
COMP1
VMON1
ISHARE
CLKOUT
EN/FF2
EN/FF1
SGND
C9
C11
VSEN1-
VIN1
PGND
E
1.2V @ 30A
VOUT
J3
24
DNP
VSEN1+
TP6
TP10
25
C10
VOUT1
12
PGOOD
PGOOD
47UF
ISL8225MIRZ
N/C
1
26
1K
19
20
18
17
16
15
14
13
GND
J4
EN
C8
TP7
470PF
6.04K
R1
E
E
S1
R2
2.05K
C7
1000PF
TP8
SGND
TP9
S1
DRAWN BY:
DATE:
ENGINEER:
RELEASED BY:
DATE:
TITLE:
UPDATED BY:
DATE:
FIGURE 2. ISL8225MEVAL3Z BOARD SCHEMATIC
TIM KLEMANN
10/18/2012
JIAN YIN
DATE:
ISL8225M
EVALUATION BOARD
SCHEMATIC
Application Note 1790
VOUT2
M1
R4
PHASE2
VSEN2+
PHASE1
PHASE1
COMP2
VMON2
MODE
SYNC
10
11
EGND
SGND
E
IN
VSEN2-
PHASE2
TP2
VCC
J2
VIN2
3.3K
C1
2
3
4
5
6
PGND
S1
S1
VCC
GND
GND_S1
7
E
8
9
470UF
3
TP5
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December 3, 2012
Application Note 1790
Layout
FIGURE 3. TOP COMPONENTS
FIGURE 4. TOP LAYER
FIGURE 5. LAYER 2
FIGURE 6. LAYER 3
4
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Application Note 1790
Layout
(Continued)
FIGURE 7. BOTTOM LAYER
5
FIGURE 8. BOTTOM COMPONENTS
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December 3, 2012
Bill of Materials
PART NUMBER
QTY.
VALUE
TOL. VOLTAGE POWER
108-0740-001
J1-J4
4
10TPB330M
C15
1
TP1-TP10
10
C1
1
470µF
20%
25V
C2-C5
4
22µF
10%
C7
1
1000pF 10%
C8, C16
2
470pF
H1045-00475-6R3V10-T
C6
1
H1045-OPEN
C9
H1046-00476-6R3V20-T
H1065-00107-6R3V20-T
PACKAGE
TYPE
JEDEC TYPE
MANUFACTURER
DESCRIPTION
CONN
BAN-JACK
Johnson
Components
Standard type banana jack
SMD
CAP_7343_149
SANYO-POSCAP
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
50V
603
CAP_0603
Generic
Multilayer capacitor
10%
50V
603
CAP_0603
Generic
Multilayer capacitor
4.7µF
10%
6.3V
603
CAP_0603
Generic
Multilayer capacitor
1
OPEN
5%
OPEN
603
CAP_0603
Generic
Multilayer capacitor
C10
1
47µF
20%
6.3V
805
CAP_0805
Generic
Multilayer capacitor
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 Intersil
5002
6
EEE1EA471P
GRM32ER71E226KE15L
H1045-00102-50V10-T
H1045-00471-50V10
H1065-OPEN
H2505-DNP-DNP-1
H2511-02051-1/10W1-T
330µF
20%
10V
THOLE
Dual 15A DC/DC power module
NOTE: Resistance accuracy of feedback resistor divider R1/R2 can affect the output accuracy. Please use high accuracy resistance (i.e. 0.5% or 0.1%) to meet the output accuracy requirement.
Application Note 1790
REF DES
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December 3, 2012
Application Note 1790
ISL8225MEVAL3Z Efficiency Curves
95
Test conditions at +25°C and no air flow.
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
25
LOAD CURRENT (A)
FIGURE 9. EFFICIENCY CURVES FOR 12V INPUT
30
70
0
5
10
15
20
25
30
LOAD CURRENT (A)
FIGURE 10. EFFICIENCY CURVES FOR 5V INPUT
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
7
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