EVK User’s Manual
ROHM Switching Regulator Solutions
Evaluation Board: Synchronous Buck
Converter Integrated FET
BD9B301MUV-EVK-101 (3.3 | 3A Output)
Introduction
This application note will provide the steps necessary to operate
and evaluate ROHM’s synchronous buck DC/DC converter
using the BD9B301MUV-EVK-101 evaluation board. Component
selection, board layout recommendations, operating procedures,
and application data are provided.
An EN pin allows for simple ON/OFF control of the IC to reduce
standby current consumption, while a MODE pin enables users
to select Fixed Frequency PWM mode or Deep SLLM control that
automatically switches between modes.
Description
This evaluation board has been specifically developed to evaluate
ROHM’s BD9B301MUV synchronous buck DC/DC converter with
integrated 32mΩ Pch high-side and Nch low-side MOSFETs.
Features include 3.3V output from 2.7V to 5.5V input and variable
switching frequency: 1MHz (FREQ pin connected to VIN) or 2MHz
(FREQ pin connected to Ground). Multiple protection cricuits are
also buil in, including a fixed soft start circuit that prevents inrush
current during startup, UVLO (Under Voltage Lock Out), and TSD
(Thermal Shutdown).
Applications
• Step-Down Power Supplies for DSPs, FPGAs,
Microcontrollers, and more
• Laptop PCs/Tablet PCs/Servers
• LCD TVs
• Storage Devices (HDDs/SSDs)
• Printers, OA Equipment
• Entertainment Devices
• Distributed and Secondary Power Supplies
Evaluation Board Operating Limits and Absolute Maximum Ratings
Parameter
Supply Voltage
BD9B301MUV
Output Voltage/Current
BD9B301MUV
V
OUT
I
OUT
─
─
3.3
─
─
3
V
A
V
CC
2.7
─
5.5
V
Symbol
Limit
MIN
TYP
MAX
Unit
Conditions
© 2017 ROHM CO., Ltd.
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No. 60UG024E Rev.001
OCT 2017
Eval Board: Synchronous Buck Converter Integrated FET
EVK User’s Manual
Evaluation Board
Figure 1: Evaluation Board for the BD9B301MUV
Board Schematic
V
OUT
R1
140
5%
1/10W
0603
PGD_LED
CR1
SML-310MTT86
LED_0603
PGD_QC
1k PGD_QB B
5%
1/10W
L1
74437349015
SMT_6P6x6P6
C5
22µF
10%
6.3V
1210
C6
22µF
10%
6.3V
1210
C7
0603
DNP
C8
0805
DNP
Q1
SST2222AT116
SOT23
AV
IN
AV
IN
V
IN
TP1
(INPUT: 2.7-5.5 VDC)
V
IN
TP2
TP3
D1
P48MA6.8A
DO-214A/C
5.8V
39.0A
C1
10µF
10%
10V
1206
AV
IN
C2
0.1µF
16
10%
16V
C3
0603
0.1µF
10%
16V
0603 5
3
4
15
7
8
9
1
2
U1
BD9B301MUV
VQFND16V3030
PV
IN
PV
IN
AV
IN
PGD
SW
SW
SW
R2
100k
5%
1/10W
0603
R3
0603
14 PGD
10 SW
11
12
(OUTPUT: 3.3V@3A)
V
OUT
TP4
C9
1206
DNP
TP5
AV
IN
1
3
AGND
PGND
PGND
EN
FREG
MODE
SS
BOOT
FB
13 BOOT
6 FB
J1
2
EN
FREQ
2
SS
C11
0603
DNP
2
MODE
C4
0.1µF
10%
16V
0603
1.5µH
20%
8A
R4
160k
1%
1/10W
0603
C10
180pF
5%
50V
0603
87224-3
J2
1
3
87224-3
J3
1
3
87224-3
EPAD 17
R5
51k
1%
1/10W
0603
V
OUT
=0.8*(R4+R5)/R5
BD9B301MUV EVM Jumper Positions
Reference
Designator
J1
Position
2-1
2-3
2-1
2-3
2-1
J3
2-3
Enable U1
Disable U1
Set switching frequency of U1 is 1.0MHz
Set switching frequency of U1 is 2.0MHz
Set operation mode of U1 is fixed frequency PWM mode
Set operation mode of U1 is automatically switched between
the Deep-SLLM control and fixed frequency PWM mode
Description
Note:
1. 0.8V=< V
OUT
=V 0.8*V
IN
J2
Figure 2: BD9B301MUV-EVK-101 Evaluation Board Schematic
© 2017 ROHM CO., Ltd.
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No. 60UG024E Rev.001
OCT 2017
Eval Board: Synchronous Buck Converter Integrated FET
EVK User’s Manual
Board I/O
Below is a reference application circuit that shows the inputs V
IN
, Enable, FREQ and MODE and the output V
OUT
.
BD9B301MUV
PV
IN
AV
IN
Enable
10µF
0.1µF
AGND
PGND
SS
MODE
C
SS
FREQ
MODE
FREQ
FB
R2
R1
C
FB
22µF x 2
SW
1.0µH
EN
PGD
BOOT
C
BOOT
V
OUT
PGD
V
IN
Figure 2: BD9B301MUV-EVK-101 Evaluation Board I/O
Operating Procedure
1.
2.
Connect the power supply’s GND terminal to GND test point TP3 on the evaluation board.
Connect the power supply’s V
CC
terminal to V
IN
test point TP2 on the evaluation board. This will provide V
IN
to the IC
U1. Please note that V
CC
should be in the range from 2.7V to 5.5V.
3.
Set the operating mode by changing the position of shunt jumper J3 (If Pin2 is connected to Pin1, the MODE pin of IC
U1 will be pulled high and IC U1 will operate in Fixed frequency PWM mode, otherwise the MODE pin of IC U1 will be
pulled low and IC U1 will operate by automatically switching between Deep-SLLM control and fixed frequency PWM
mode).
4.
Set the switching frequency by changing the position of shunt jumper J2 (If Pin2 is connected to Pin1, the FREQ pin
of IC U1 will be pulled high and IC U1 will switch frequency to 1.0MHz, otherwise the FREQ pin of IC U1 will be pulled
low and the the frequency will be switched to 2.0MHz).
5.
6.
7.
Check if shunt jumper J1 is the ON position (Connect Pin 2 to Pin 1, the EN pin of IC U1 is pulled high as a default).
Connect the electronic load to TP4 and TP5. Do not turn on the load.
Turn on the power supply. The output voltage V
OUT
(+3.3V) can be measured at the test point TP4. Now turn on the
load. The load can be increased up to 3A MAX.
© 2017 ROHM CO., Ltd.
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No. 60UG024E Rev.001
OCT 2017
Eval Board: Synchronous Buck Converter Integrated FET
EVK User’s Manual
Reference Application Data
The following are graphs of the hot plugging test, quiescent current, efficiency, load response, and output voltage ripple response of
the BD9B301MUV-EVK-101 evaluation board.
Fig 4: Hot Plug-in Test with Zener Diode
P4SMA6.8A, V
IN
=5.5V, V
OUT
=3.3V,
I
OUT
=3A, FREQ=L, MODE=L
Fig 5: Circuit Current vs. Power Supply
Voltage Characteristics (Temp=25ºC,
FREQ=L, MODE=L)
Fig 6: Electric Power Conversion Rate
(V
OUT
=3.3V, FREQ=L, MODE=L)
Fig 7: Load Response Characteristics
(V
IN
=5V, V
OUT
=3.3V, I
OUT
=0 → 3A, FREQ=L, MODE=L)
Fig 8: Load Response Characteristics
(V
IN
=5V, V
OUT
=3.3V, I
OUT
=3A → 0, FREQ=L, MODE=L)
Fig 9: Output Voltage Ripple Response Characteristics
(V
IN
=5V, V
OUT
=3.3V, I
OUT
=0, FREQ=L, MODE=L)
Fig 10: Output Voltage Ripple Response Characteristics
(V
IN
=5V, V
OUT
=3.3V, I
OUT
=3A, FREQ=L, MODE=L)
© 2017 ROHM CO., Ltd.
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No. 60UG024E Rev.001
OCT 2017
Eval Board: Synchronous Buck Converter Integrated FET
EVK User’s Manual
Typical Performance Data - continued
Fig 11: Hot Plug-in Test with Zener Diode
P4SMA6.8A, V
IN
=5.5V, V
OUT
=3.3V,
I
OUT
=3A, FREQ=L, MODE=H
Fig 12: Circuit Current vs. Power Supply
Voltage Characteristics (Temp=25ºC,
FREQ=L, MODE=H)
Fig 13: Electric Power Conversion Rate
(V
OUT
=3.3V, FREQ=L, MODE=H)
Fig 14: Load Response Characteristics
(V
IN
=5V, V
OUT
=3.3V, I
OUT
=0 → 3A, FREQ=L, MODE=H)
Fig 15: Load Response Characteristics
(V
IN
=5V, V
OUT
=3.3V, I
OUT
=3A → 0, FREQ=L, MODE=H)
Fig 16: Output Voltage Ripple Response Characteristics
(V
IN
=5V, V
OUT
=3.3V, I
OUT
=0, FREQ=L, MODE=H)
Fig 17: Output Voltage Ripple Response Characteristics
(V
IN
=5V, V
OUT
=3.3V, I
OUT
=3A, FREQ=L, MODE=H)
© 2017 ROHM CO., Ltd.
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No. 60UG024E Rev.001
OCT 2017
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