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© 2017 ROHM Co., Ltd.
No. 60AP001E Rev.001
2017.4
© 2017 ROHM Co., Ltd.
No. 60UG002E Rev.001
APR.2017
User’s Guide
Switching Regulator Series
Step-Down DC/DC Converter
BD9A101MUV-LB Evaluation Board
BD9A101MUV-EVK-001
This evaluation board has been developed for ROHM’s synchronous buck DC/DC converter customers evaluating BD9A101MUV-LB. While
accepting a power supply of 2.7-5.5V, an output of 1.8V can be produced. The IC has internal 60mΩ high-side N-channel MOSFET and 60mΩ low-
side N-channel MOSFET and a synchronization frequency is of 1MHz. 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. A MODE pin allows the user to select fixed frequency PWM mode or
enables the light load mode control and the mode is automatically switched between the light load mode control and fixed frequency PWM mode.
Include OCP (Over Current Protection) and SCP (Short Circuit Protection).
Evaluation Board Operating Limits and Absolute Maximum Ratings (Ta=25℃)
Parameter
Limit
Unit
Conditions
MIN
TYP
MAX
Supply Voltage
2.7
-
5.5
V
Output Voltage / Current
-
1.8
-
V
-
-
1
A
Evaluation Board
Figure 1. BD9A101MUV-EVK-001 Evaluation Board
GND
Vout
BD9673EFJ Eval Board
EN
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User’s Guide
BD9A101MUV-EVK-001
© 2017 ROHM Co., Ltd.
No. 60UG002E Rev.001
APR.2017
Operation Procedures
1. Necessary equipments
(1) DC power-supply of 2.7V to 5.5V/1A
(2) Maximum 1A load
(3) DC voltmeter
2. Connecting the equipments
(1) DC power-supply presets to 5.0V and then the power output turns off.
(2) The maximum load should be set at 1A and over it will be disabled.
(3) Check Jumper pin of SW1 is short, between intermediate-terminal and OFF-side terminal.
(4) Connect positive-terminal of power-supply to VIN+ terminal and negative-terminal to GND-terminal with a pair of wires.
(5) Connect load’s positive-terminal to VOUT+ terminal and negative-terminal to GND-terminal with a pair of wires.
(6) Connect positive-terminal of DC voltmeter 1 to TP1 and negative-terminal to TP2 for input-voltage measurement.
(7) Connect positive-terminal of DC voltmeter 2 to TP3 and negative-terminal to TP4 for output-voltage measurement.
(8) DC power-supply output is turned ON.
(9) IC is enable (EN) by shorting Jumper-pin of SW1 between intermediate-terminal and ON-side terminal.
(10) Check DC voltmeter 2 displays 1.8V.
(11) The load is enabled.
(12) Check at DC voltmeter 1 whether the voltage-drop (loss) is not caused by the wire’s resistance.
Figure 2. Connection Diagram
Enable-Pin
To minimize current consumption during standby-mode and normal operation, Enable-mode can be switched by controlling EN
pin (15pin) of the IC. Standby-mode is enabled by shorting Jumper-pin of SW1 between intermediate-terminal and OFF-side
terminal and normal-mode operation by shorting between intermediate-terminal and ON-side terminal.
It also can be switched between standby-mode and normal-mode operation by removing Jumper-pin and controlling the voltage
between EN and GND-terminal. Standby-mode is enabled when the voltage of EN is under 0.5V, and normal-mode operation when
it is over 2.0V.
+
−
+
−
+
−
DC Power
+
−
DC Voltmeter 1
DC Voltmeter 2
V
V
Load
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BD9A101MUV-EVK-001
© 2017 ROHM Co., Ltd.
No. 60UG002E Rev.001
APR.2017
1 PVIN
3 PGND
15 EN
5 AGND
SW 12
ITH 7
FB 6
U1
BD9A101MUV-LB
C2 L1 C4
C8
R3
R1
R2
VIN VOUT
C5
17 EPAD
C1
C10
C3
SW1
ON
OFF
GND
J1TP1
TP2
J2
TP3
TP4GND
TP5
TP6
C6
SW 11
SW 10
SS 9TP7
C9
BOOT 13
C7
R7
14 PGD
R4
16 AVIN
2 PVIN
4 PGND
8 MODE
R5
R6
PGD
Circuit Diagram
VIN = 2.7V～5.5V, VOUT = 1.8V
Figure 3. BD9A101MUV-EVK-001 Circuit Diagram
Bill of Materials
2 C1, C7 Ceramic Capacitor 0.1µF
50V, B, ±10% GRM188B31H104KA92D MURATA 1608
1C2 Ceramic Capacitor 10µF
16V, B, ±10% GRM31CB31C106KA88L MURATA 3216
0C3 Ceramic Capacitor
- Not installed - - 3216
2 C4, C5 Ceramic Capacitor
22µF 6.3V, B, ±20% GRM21BB30J226ME38L MURATA 2012
0C6 Ceramic Capacitor
- Not installed - - 2012
1C8 Ceramic Capacitor
2700pF 50V, B, ±10% GRM188B11H272KA01D MURATA 1608
1C9 Ceramic Capacitor
0.01µF 50V, B, ±10% GRM188B11H103KA01D MURATA 1608
0C10 Ceramic Capacitor
- Not installed - - 1608
1L1 Inductor
2.2µH ±20%, DCR=17mΩmax, 8.1A FDSD0630-H-2R2M TOKO 7066
1R1 Resistor
30kΩ 1/10W, 50V, ±1% MCR03EZPFX3002 ROHM 1608
1R2 Resistor
24kΩ 1/10W, 50V, ±1% MCR03EZPFX2402 ROHM 1608
1R3 Resistor
9.1kΩ 1/10W, 50V, ±1% MCR03EZPFX9101 ROHM 1608
1R4 Resistor
10kΩ 1/10W, 50V, ±1% MCR03EZPFX1002 ROHM 1608
2 R5, R7 Resistor
0Ω Jumper MCR03EZPJ000 ROHM 1608
0R6 Resistor
- Not installed - - 1608
PH-1x03SG USECONN -
61300311121 Wurth Electronics Inc. -
1U1 IC
- Buck DC/DC Converter BD9A101MUV-LB ROHM VQFN016V3030
TB111-2-2-U-1-1 Alphaplus Connectors & Cables -
OSTTC022162 On Shore Technology Inc -
MJ254-6BK USECONN -
969102-0000-DA 3M -
1 - PCB
- FR4, 4-layer, 1oz EVK029 Rev.A Tamukai 50×50×1.6
1
-
Jumper
-
Jumper pin for SW1
2
J1, J2
Terminal Block
-
2 contacts, 15A, 14 to 22AWG
1
SW1
Pin header
-
2.54mm × 3 contacts
Reference
Designator
Count
Manufacturer
Part Number
Manufacturer
Configuration
(mm)
Type
Value
Description
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User’s Guide
BD9A101MUV-EVK-001
© 2017 ROHM Co., Ltd.
No. 60UG002E Rev.001
APR.2017
Layout
PCB size：50mm×50mm×1.6mm
Figure 4. Top Silk Screen (Top view)
Figure 5. Top Silk Screen and Layout (Top view)
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User’s Guide
BD9A101MUV-EVK-001
© 2017 ROHM Co., Ltd.
No. 60UG002E Rev.001
APR.2017
Figure 6. Top Side Layout (Top view)
Figure 7. L2 Layout (Top view)
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User’s Guide
BD9A101MUV-EVK-001
© 2017 ROHM Co., Ltd.
No. 60UG002E Rev.001
APR.2017
Figure 8. L3 Layout (Top view)
Figure 9. Bottom Side Layout (Top view)
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User’s Guide
BD9A101MUV-EVK-001
© 2017 ROHM Co., Ltd.
No. 60UG002E Rev.001
APR.2017
0
10
20
30
40
50
60
70
80
90
100
0.001 0.01 0.1 1
Efficiency (%)
Load Current (A)
VIN=3.3V
VIN=5.0V
VO=1.8V
-0.4
-0.3
-0.2
-0.1
0
0.1
0.2
0.3
0.4
2 2.5 3 3.5 4 4.5 5 5.5 6
Output Voltage Change (%)
Input Voltage (V)
-0.5
-0.4
-0.3
-0.2
-0.1
0
0.1
0.2
0.3
0.4
0.5
0 0.2 0.4 0.6 0.8 1
Output Voltage Change (%)
Load Current (A)
VIN=5.0V
VO=1.8V
Reference Application Data
Figure 10. Efficiency vs Load Current
Figure 11. Line Regulation
Figure 12. Load Regulation
Figure 13. Load Transient Characteristics
VO (AC)
50mV/div
IO: 0.5A/div
VIN = 5.0V
VO = 1.8V
IO: 0A→1A→0A
Time scale 1ms/div
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User’s Guide
BD9A101MUV-EVK-001
© 2017 ROHM Co., Ltd.
No. 60UG002E Rev.001
APR.2017
-180
-135
-90
-45
0
45
90
135
180
-80
-60
-40
-20
0
20
40
60
80
1000 10K 100K 1M
Phase (deg)
Gain (dB)
Frequency (Hz)
Figure 14. Loop Response VIN = 5.0V, VO = 1.8V, IO = 1.0A
Phase
Gain
Figure 15. Input Voltage Ripple Wave
VIN = 5.0V, VO = 1.8V, IO=0A
Figure 16. Input Voltage Ripple Wave
VIN = 5.0V, VO = 1.8V, IO=1A
VIN (AC)
50mV/div
Time scale 20ms/div
VSW
2V/div
Time scale 1μs/div
VIN (AC)
50mV/div
VSW
2V/div
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User’s Guide
BD9A101MUV-EVK-001
© 2017 ROHM Co., Ltd.
No. 60UG002E Rev.001
APR.2017
Time scale 2ms/div
VO (AC)
20mV/div
VSW
2V/div
Figure 17. Output Voltage Ripple Wave
VIN = 5.0V, VO = 1.8V, IO=0A
Time scale 1μs/div
VIN
5V/div
EN
5V/div
VO
1V/div
Time scale 1ms/div
Time scale 1ms/div
Figure 19. Start-up by EN
VIN = 5.0V, VO = 1.8V
Figure 20. Power-down by EN
VIN = 5.0V, VO = 1.8V
Figure 18. Output Voltage Ripple Wave
VIN = 5.0V, VO = 1.8V, IO=1A
VO (AC)
20mV/div
VSW
2V/div
VSW
5V/div
R1102
B
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