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© 2014 ROHM Co., Ltd. All rights reserved. www.rohm.com 9 December 2014 Rev.002
Switching Regulator Series Step-Down DC/DC Converter BD9C401EFJ Evaluation Board BD9C401EFJ-EVK-001
Description This evaluation board has been developed for ROHM’s synchronous buck DC/DC converter customers evaluating BD9C401EFJ. While accepting a power supply of 4.72-18V, an output of 3.3V can be produced. The IC has internal 65mΩ high-side P-channel MOSFET and 35mΩ low-side N-channel MOSFET and a synchronization frequency is of 500kHz. A Soft Start circuit prevents in-rush current during startup. An EN pin allows for simple ON/OFF control of the IC to reduce standby current consumption. Include OCP (Over Current Protection) and SCP (Short Circuit Protection).
Evaluation Board Operating Limits and Absolute Maximum Ratings (Ta=25)
Parameter Symbol Limit
Unit Conditions MIN TYP MAX
Supply Voltage VCC 4.5 - 18 V
Output Voltage / Current
VOUT - 3.3 - V
IOUT - - 4 A
(NOTE1) When the output voltage is 3.3V, it is 4.72V by limiting ratio of the maximum duty.
Evaluation Board
Figure 1. BD9C401EFJ-EVK-001 Evaluation Board
(NOTE1)
BD
© 2ww
Op 1. N
2. C
En
It abetwh
D
D9C401EF
2014 ROHM Coww.rohm.com
peration Pro
Necessary eq
(1) DC powe
(2) Maximum
(3) DC voltme
Connecting th
(1) DC powe
(2) The max.
(3) Check Ju
(4) Connect p
(5) Connect l
(6) Connect p
(7) Connect p
(8) DC powe
(9) IC is enab
(10) Check D
(11) The load
(12) Check a
nable-Pin
To minimizeEN pin(6pin)OFF-side ter
also can be swtween EN anden it is over 2
DC Pow
DC Voltmeter 1
FJ-EVK-00
o., Ltd. All rights
ocedures
uipments
r-supply of 4.7
m 4A load
eter
he equipments
r-supply prese
load should b
mper pin of S
positive-termin
load’s positive
positive-termin
positive-termin
r-supply outpu
ble (EN) by sh
DC voltmeter 2
d is enabled.
at DC voltmete
e current cons) of the IC. Sminal and norwithed betweed GND-termina.0V.
+
-
+
-
wer
V
01
reserved.
7V to 18V/4A
s
ets to 12V and
be set at 4A an
W1 is short, b
nal of power-s
e-terminal to V
nal of DC voltm
nal of DC voltm
ut is turned ON
horting Jumpe
2 displays 3.3V
er 1 whether th
sumption durinStandby-modermal-mode opeen standby-moal. Standby-m
d then the pow
nd over it will b
between interm
supply to VIN+
VOUT+termina
meter 1 to TP
meter 2 to TP3
N.
r-pin of SW1 b
V.
he voltage-dro
Figure 2
ng standby-moe is enabled eration by shoode and norm
mode is enable
2/8
wer output turn
be disabled.
mediate-termin
+terminal and
al and negative
1 and negativ
3 and negativ
between interm
op (loss) is not
2. Connection
ode and normby shorting
orting betweenmal-mode opered when the v
ns off.
nal and OFF-s
negative-term
e-terminal to G
e-terminal to T
e-terminal to T
mediate-termi
t caused by th
Diagram
mal operation, Jumper-pin o
n intermediateration by removoltage of EN
9
side terminal.
minal to GND-te
GND-terminal
TP2 for input-v
TP4 for output
nal and ON-si
he wire’s resist
Enable-mode of SW1 betwe-terminal and
oving Jumper-is under 0.8V
9 December
erminal with a
with a pair of
voltage measu
t-voltage mea
ide terminal.
tance.
can be switcheen intermedON-side term
-pin and contrV, and normal-
+
-
+
- V
r 2014 Rev.0
a pair of wires.
wires.
urement.
surement.
hed by controliate-terminal
minal. rolling the voltmode opera
DC Voltmete
Load
002
.
lling and
tage ation
r 2
3/8
BD9C401EFJ-EVK-001
9 December 2014 Rev.002© 2014 ROHM Co., Ltd. All rights reserved. www.rohm.com
2 VIN
6 EN
1 PGND
3 AGND
R3
C6SW1
ON
O FF
C2 C3 TP 1
V I N
GND
SW 8
TP5L1
C 4 C5
TP3
VOUT
GND
FB 4
R2
R 1
C 7
U1
BD9C401EFJ
COMP 5
TP 2
C1
TP4
J1 J2
TP6
SW 7
9 E-PAD
1 C1 Ceramic Capacitor 0.1µF 50V, B, ±20% GRM188B31H104MA92 MURATA 1608
1 C2 Ceramic Capacitor 10µF 35V, B, ±10% GRM32EB3YA106KA12 MURATA 3225
0 C3 Ceramic Capacitor - Not installed - MURATA 3225
2 C4, C5 Ceramic Capacitor 22µF 10V, B, ±10% GRM31CB31A226KE19 MURATA 3216
1 C6 Ceramic Capacitor 4700pF 25V, B, ±10% GRM188B11E472KA01 MURATA 1608
1 C7 Ceramic Capacitor 33pF 50V, C0G, ±5% GRM1885C1H330JA01 MURATA 1608
1 L1 Inductor 4.7µH ±20%, DCR=39.4mΩmax, 6.2A SPM6530T-4R7 TDK 7165
1 R1 Resistor 7.5kΩ 1/10W, 50V, 1% MCR03ERPF7501 ROHM 1608
1 R2 Resistor 2.4kΩ 1/10W, 50V, 1% MCR03ERPF2401 ROHM 1608
1 R3 Resistor 12kΩ 1/10W, 50V, 1% MCR03ERPF1202 ROHM 1608
1 SW1 Pin header - 2.54mm × 3 contacts PH-1x03SG USECONN -
1 U1 IC - Buck DC/DC Converter BD9C401EFJ ROHM HTSOP-J8
2 J1, J2 Terminal Block - 2 contacts, 15A, 14 to 22AWG TB111-2-2-U-1-1Alphaplus
Connectors & Cables
-
1 - Jumper - Jumper pin for SW1 MJ254-6BK USECONN -
ReferenceDesignator
CountManufacturerPart Number
ManufacturerConfiguration
(mm)Type Value Description
Cricuit Diagram
VIN = 4.72V~18V, VOUT = 3.3V
Figure 3. BD9C401EFJ-EVK-001 Circuit Diagram Bill of Materials
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BD9C401EFJ-EVK-001
9 December 2014 Rev.002© 2014 ROHM Co., Ltd. All rights reserved. www.rohm.com
Layout
Figure 4. Top Silk Screen (Top view)
Figure 5. Top Silk Screen and Layout (Top view)
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BD9C401EFJ-EVK-001
9 December 2014 Rev.002© 2014 ROHM Co., Ltd. All rights reserved. www.rohm.com
Figure 6. Top Side Layout (Top view)
Figure 7. L2 Layout (Top view)
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BD9C401EFJ-EVK-001
9 December 2014 Rev.002© 2014 ROHM Co., Ltd. All rights reserved. www.rohm.com
Figure 8. L3 Layout (Top view)
Figure 9. Bottom Side Layout (Top view)
BD
© 2ww
Effi
i(%
)O
utpu
t Vol
tage
(V
)
D9C401EF
2014 ROHM Coww.rohm.com
0
10
20
30
40
50
60
70
80
90
100
0
Effi
cien
cy (
%)
3.25
3.26
3.27
3.28
3.29
3.30
3.31
3.32
3.33
3.34
3.35
0
FJ-EVK-00
o., Ltd. All rights
0.5 1
L
Figure 10. E
Figure
1
Lo
01
reserved.
1.5
oad Current
Efficiency vs L
e 12. Load Re
2
ad Current (A
2 2.5
(A)
VIN=12VVO=3.3V
oad Current
gulation
3
A)
VIN=1VO=3.
7/8
3
VV
VO (A100m
IO: 1
3
3
3
3
3
3
3
3
3
3
3
Out
put V
olta
ge (
V)
4
2V.3V
F
AC) mV/div
1A/div
3.20
3.22
3.24
3.26
3.28
3.30
3.32
3.34
3.36
3.38
3.40
4 6
9
Figure
igure 13. Load
IO: 0A
6 8
Inp
9 December
11. Line Regu
d Transient Ch
Time
VV
A→2A→0A
10 12
put Voltage (
r 2014 Rev.0
ulation
haracteristics
e scale 1ms/d
VIN = 12V VO = 3.3V
14 16
V)
VO=3.3VIO=0A
002
div
18
V
BD
© 2ww
V2
D9C401EF
2014 ROHM Coww.rohm.com
VIN (AC) 20mV/div
VSW 5V/div
VSW
10V/div
EN 5V/div
VO 2V/div
FJ-EVK-00
o., Ltd. All rights
Figure 14. OuV
Figure 16. V
01
reserved.
utput Voltage VIN = 12V, VO
T
Start-up by ENVIN = 12V, VO
T
Ripple Wave= 3.3V
Time scale 1
IO = 0A
N = 3.3V, IO = 0
Time scale 1m
8/8
μs/div
VIN (A20m
V5
0A
ms/div
VSW
10V
EN5V
VO
2V
Fig
AC) V/div
VSW 5V/div
F
W
V/div
N V/div
O V/div
9
gure 15. OutpVIN
Figure 17. PowVIN
9 December
put Voltage Rip = 12V, VO = 3
Tim
Time s
wer-down by E= 12V, VO = 3
r 2014 Rev.0
pple Wave 3.3V
IO = 4A
e scale 1μs/d
scale 200ms/d
EN 3.3V, IO = 0A
002
div
div
R1102Awww.rohm.com© 2014 ROHM Co., Ltd. All rights reserved.
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