Rohm BD9611MUV EVK User manual

1ch Buck switching regulator
BD9611MUV EVK
BD9611MUV-EVK-001 (24V → 12V, 10A)

Notice
HVA01E
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＜High Voltage Safety Precautions＞
◇Read all safety precautions before use
Please note that this document covers only the BD9611MUV evaluation board (BD9611MUV-
EVK-001) and its functions. For additional information, please refer to the datasheet.
To ensure safe operation, please carefully read all precautions before
handling the evaluation board
Depending on the configuration of the board and voltages used,
Potentially lethal voltages may be generated.
Therefore, please make sure to read and observe all safety precautions described in
the red box below.
Before Use
[1] Verify that the parts/components are not damaged or missing (i.e. due to the drops).
[2] Check that there are no conductive foreign objects on the board.
[3] Be careful when performing soldering on the module and/or evaluation board to ensure that solder
splash does not occur.
[4] Check that there is no condensation or water droplets on the circuit board.
During Use
[5] Be careful to not allow conductive objects to come into contact with the board.
[6] Brief accidental contact or even bringing your hand close to the board may result in
discharge and lead to severe injury or death.
Therefore, DO NOT touch the board with your bare hands or bring them too close to the board.
In addition, as mentioned above please exercise extreme caution when using conductive tools such as
tweezers and screwdrivers.
[7] If used under conditions beyond its rated voltage, it may cause defects such as short-circuit or,
depending on the circumstances, explosion or other permanent damages.
[8] Be sure to wear insulated gloves when handling is required during operation.
After Use
[9] The ROHM Evaluation Board contains the circuits which store the high voltage. Since it stores the
charges even after the connected power circuits are cut, please discharge the electricity after using it,
and please deal with it after confirming such electric discharge.
[10] Protect against electric shocks by wearing insulated gloves when handling.
This evaluation board is intended for use only in research and development facilities and
should by handled only by qualified personnel familiar with all safety and operating
procedures.
We recommend carrying out operation in a safe environment that includes the use of high
voltage signage at all entrances, safety interlocks, and protective glasses.

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© 2014 ROHM Co., Ltd.
No. 65UG056E Rev.005
OCT.2023
User’s Guide
ROHM Switching Regulator Solutions
1ch Buck switching regulator
BD9611MUV EVK
BD9611MUV-EVK-001 (24V → 12V, 10A)
Introduction
This user’s guide will provide the steps necessary to operate the BD9611MUV-EVK-001 and evaluate ROHM’s BD9611MUV synchronous
buck-boost DC/DC controller. Component selection, operating procedures and application data are included.
Description
Using a synchronous rectified step-down DC/DC converter IC BD9611MUV, BD9611MUV-EVK-001 evaluation board outputs 12 V with a 15V
to 36V input voltage and provides 10A output current. Output current is possible with current settings by selecting high rated current FET and
coil. It is possible to adjust the loop characteristics by phase compensation components and can set the output voltage by changing the IC
external parts.
Application
General Portable Equipment such as:
•Amusement machines
•Industrial Equipment
•Office Automation Equipment
•LED lighting
•General equipment that require 24V or 48V supply
Evaluation Board Operating Limits and Absolute Maximum Ratings
(This is not typical and the characteristics）
Unless otherwise specified：VIN = 24V, VOUT = 12V, IOUT=6A
Table 1. Operating Limits
Parameter
Min
Typ
Max
Units
Conditions
Supply Voltage
15
36
V
Output Voltage
12
V
RU1=120kΩ, RU2=20kΩ,
RD1=10kΩ, RD2=short
Output Voltage range
1
VIN×0.8
V
Output Current
0
10
A
Closed Loop Band Width
12.02
kHz
Phase margin
82.34
°
IOUT = 8A
Soft Start Time
8
ms
Operating frequency
250
kHz
Maximum Efficiency
95.1
%
IOUT = 4A

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User’s Guide
BD9611MUV-EVK-001
© 2015 ROHM Co., Ltd.
No. 65UG056E Rev.005
SEP.2023
EVK overview
Figure 1. BD9611MUV-EVK-001(Top View) Figure 2. BD9611MUV-EVK-001(Bottom View)
EVK Schematic
VIN = 15V to 36V, VOUT = 12V
Figure 3. BD9611MUV-EVK-001 Application circuit
CREG5
VIN
VOUT
CRTSS
RCL
RT
SS
GND
INV
FB
RCL
RTSS
CLKOUT
PGND
SYNC
LG
REG10
LX
HG
BST
CLL
CLH
VCC
REG5
CTL
BD9611MUV
CVCC
CBST
CREG10
COUT1
CIN
RT
CSS
RU1
RU2
RD1
R2
C1
C2
C3
Tr1
Tr2
L1
R0
RD2
RD3
RD4
R1
RLG
RHG
RBST
RS
SW1
R4
J2
RCLH
RCLL
CCL
CSYNC
RSYNC
+
RCLK
J1
RVCC
R3
COUT2
R9
R7
R5
CCTL
R8
R6
DI1
DI2 DI3
RSNB
CSNB

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Operating Procedure
1. Connect power supply’s GND terminal to GND on the evaluation board.
2. Connect power supply’s VIN terminal to VIN test point on the evaluation board. This will provide the power supply voltage to
the IC. The EN pin of this evaluation board is set to input the resistive divided voltage of the VIN pin.
3. The output voltage can be measured at the test point VOUT. Now turn on the load. Connect an electronic load or resistive
load to the VOUT pin and apply the load.The load can be increased up to 10A MAX.
Figure 4. Evaluation board setup
Enable
The board can switch between normal operation and standby mode to minimize power consumption by controlling the CTL of
the IC (19 pin). By default, it is controlled using voltage divider resistor network of R5, R6, R7, and R8 which is referenced from
VIN.
SW1 is not mounted on the EVK, but when using SW1, opening R5, R6, R7, and R8 and shorting R9, enables the use of SW1.
Switching it to the GND will enter Standby Mode while switching it to VIN will enter to Normal operation.
In addition, by removing R9 and controlling the voltage between the CTL and GND pins, standby mode and normal operation
can be switched. When the voltage on the CTL pin is less than 2.6V, standby mode is used, and when the voltage is 2.6V or
higher, normal operation is performed. Since the hysteresis voltage is set by an internal low current and an external resistor,
when the CTL pin is directly controlled by voltage, the hysteresis voltage is determined by the impedance of the power supply
supplying the voltage to the CTL pin and the internal constant current.
+
-
+
-
+
-
DC
power
supply
+
-
DC voltmeter 1
DC voltmeter 2
V
V
Load current

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OCT.2023
Evaluation Board BOM (VOUT =12V)
Table 2. Part list (12V output voltage setting)
Coun
t
Parts No.
Type
Value
Description
Manufacturer
Manufacturer
Configuration
Part Number
inch(mm)
1
U1
IC
-
Buck DC/DC
Controller
BD9611MUV-E2
ROHM
1515(4040)
1
R1
Resistor
1kΩ
0.1W, 1%
MCR03EZPFX1001
ROHM
0603(1608)
1
R2
Resistor
15kΩ
0.1W, 1%
MCR03EZPFX1502
ROHM
0603(1608)
1
R5
Resistor
27kΩ
0.1W, 1%
MCR03EZPFX2702
ROHM
0603(1608)
1
R7
Resistor
5.1kΩ
0.1W, 1%
MCR03EZPFX5101
ROHM
0603(1608)
1
R8
Resistor
430Ω
0.1W, 1%
MCR03EZPFX4300
ROHM
0603(1608)
1
RU1
Resistor
120kΩ
0.1W, 1%
MCR03EZPFX1203
ROHM
0603(1608)
2
RU2, RCL
Resistor
20kΩ
0.1W, 1%
MCR03EZPFX2002
ROHM
0603(1608)
1
RD1
Resistor
10kΩ
0.1W, 1%
MCR03EZPFX1002
ROHM
0603(1608)
1
RT
Resistor
75kΩ
0.1W, 1%
MCR03EZPFX7502
ROHM
0603(1608)
1
RHG
Resistor
10Ω
0.1W, 1%
MCR03EZPFX10R0
ROHM
0603(1608)
2
DI1, DI2
Diode
20V/
1A
VF(max)=0.42V
@IF=1A
RB161VAM-20TR
ROHM
0705(2014)
1
RS
Resistor
5mΩ
2W, 1%
PMR100HZPFU5L00
ROHM
6432(2512)
1
C1
Ceramic
Capacitor
180pF
100V, 5%, NP0
GRM1555C2A181JE01
MURATA
0402(1005)
1
C2
Ceramic
Capacitor
2200pF
50V, 5%, CH
GRM1882C1H222JA01
MURATA
0603(1608)
2
CSS, CRTSS
Ceramic
Capacitor
0.01µF
50V, 5%, CH
GRM1882C1H103JA01D
MURATA
0603(1608)
1
CREG10
Ceramic
Capacitor
1µF
50V, 10%, X5R
GRM155R61H105KE05
MURATA
0402(1005)
1
CBST
Ceramic
Capacitor
0.47µF
25V, 10%, X7R
GRM188R71E474KA12D
MURATA
0603(1608)
4
CIN
Ceramic
Capacitor
10µF
100V, 22%, X7S
GRM32EC72A106KE05K
MURATA
1210(3225)
1
COUT1
Aluminum
Electrolytic
Capacitor
220µF
50V, 20%
UVR1H221MPD1TD
Nichicon
0504(1210)
4
COUT2
Ceramic
Capacitor
10µF
50V, 10%, B
GRM32EB31H106MA12
MURATA
1210(3225)
1
CVCC
Ceramic
Capacitor
1µF
100V, 22%, X7S
GRM21BC72A105KE01
MURATA
0805(2012)
1
CREG5
Ceramic
Capacitor
0.1µF
25V, 10%, X7R
GRM155R71E104KE14D
MURATA
0402(1005)
2
Tr1, Tr2
FET
60V/
22A
Nch, VGS=3V,
RDS(on)=18mΩ
30nC,DPAK-3
RD3L220SNTL1
ROHM
2426(6266)
1
L1
Inductor
7.7µH
10A
CDEP147NP-7R7MC-95
Sumida
0.59 x 0.59
(14.9 x 14.9)
11
R0, R6, RD2,
RLG, RBST,
RCLH, RCLL,
RVCC,
CSYNC, J2,
DI3
-
-
Short
-
-
-
10
R3, R4, R9,
RD3, RD4, C3
RCLK,
RSYNC, CCL,
J1
-
-
Open
-
-
-
Recommended parts are selected from those products and information available at the time this data sheet (Rev.004) was
released. If supply conditions change and parts are not available, use similar parts.

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BD9611MUV-EVK-001
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LX pin overshoot voltage countermeasure: Snubber Circuit
Overshoot voltage of LX pin is caused by the parasitic capacitance of the high-side and low-side FET and parasitic inductance
of the board layout pattern. The power supply voltage range and load range used, and also the output short circuit must ensure
that LX pin voltage does not exceed the recommended operating range.
If the overshoot voltage of the LX pin is large, set a snubber circuit in where the resistor RSNB and the capacitor CSNB are
connected in series between the LX pin and PGND, as described in Figure 5 and prevent overshoot.
※RSNB and CSNB are not in the evaluation board pattern. It is recommended to place the pattern to allow countermeasures
when an overshoot occurs.
VIN
VOUT
LG
LX
HG
BST
CBST
COUT1
CIN
Tr1
Tr2
L1
RLG
RHG
RBST RS
+
COUT2
DI1
RSNB
CSNB
Figure 5. Snubber circuit
DI2 and DI3 between output voltage and REG10
By connecting the diode of DI3 between the output and REG10, loss can be reduced by supplying power from the output
voltage instead of REG10 inside the IC.
For the REG10 maximum rated voltage of 15V, it is necessary to consider output voltage fluctuations (IC variations, resistance
tolerances, load fluctuations) and other factors.
＜Precaution＞
This document is an example of BD9611MUV application circuit and operation; it is not a guarantee to work.

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Reference Application Data
Figure 6. Efficiency – Load Current
Figure 8. Load Regulation
Figure 10. Load Response Characteristics
(10A → 0A)
Figure 7. Line Regulation
Figure 9. Load Response Characteristics
(0A → 10A)
Figure 11. Start-up waveform (Soft Start)
50
55
60
65
70
75
80
85
90
95
100
0246810
Efficiency (%)
Load Current (A)
VIN=24V
VIN=30V VOUT=12V
11.6
11.7
11.8
11.9
12.0
12.1
12.2
12.3
12.4
0 2 4 6 8 10
Output voltage (V)
Load Current (A)
VIN=24V
VIN=30V
VOUT=12V
11.600
11.700
11.800
11.900
12.000
12.100
12.200
12.300
12.400
15 20 25 30
Output voltage (V)
Input Voltage (V)
VOUT=12V
IOUT=6A
VIN=24V
VIN=24V
IOUT=0A
VIN=24V

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Figure 12. Start-up waveform (Pre-Bias)
Figure 14. LX Terminal Waveform
Figure 16. OCP Waveform (Zoom in)
Figure 13. LX Terminal Waveform
Figure 15. OCP Waveform
Figure 17. Frequency Response, VIN=24V, VOUT=12V / 8A
VIN=30V
VOUT=12V
IOUT=6A
VIN=24V
VOUT=12V
IOUT=6A
VIN=24V
VOUT=12V
IOUT=0A
VIN=24V
VOUT=12V
IOUT=0A
fc=12.02kHz
Phase margin=82.34°
VIN=24V
Io=0A
VIN=24V
VOUT=11V
IOUT=0A

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Figure 18. OCP Waveform
Figure 19. OCP Waveform (Zoom in)
Board Layout
EVK PCB information
Number of
Layers
Material
Board Size
Copper
Thickness
4
FR-4
80mm x 80mm x 1.6mmt
1oz (35μm)
Followings are the layout of BD9611MUV-EVK-001
Figure 20. Top Silkscreen (Top view)
VIN=30V
VOUT=12V
IOUT=0A
VIN=30V
VOUT=12V
IOUT=0A

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Figure 21. Bottom Silkscreen (Bottom view)
Figure 22. Top Layer (Top view)

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Figure 23. L2 Layer (Middle view)
Figure 24. L3 Layer (Middle view)

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Figure 25. Bottom Layer (Bottom view)
Products listed in the Part list
The product names listed in the part list are available ones at the time of creating this user’s guide. In case some parts are
no longer available in the future, select the equivalent products.

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No. 65UG056E Rev.005
OCT.2023
Revision History
Date
Revision
Number
Description
9. Dec. 2014
001
Initial release
21. Aug. 2015
002
p.1 Corrected "maximum 8A" to "maximum 10A”.
8. Dec. 2015
003
p.4 Update part number of resistor MCR03EZPF to MCR03EZPFX in table 2.
30. Nov. 2022
004
p.1 Updated “Introduction” and “Application”.
p.1 Corrected " with a 15V to 24V input voltage " to " with a 15V to 36V input voltage”.
p.2 Updated “EVK overview”.
p.2 Changed schematic drawing. There is no change in component constants.
p.2 Corrected "VIN 30V" to "VIN 36V”.
p.4 Update part number of Tr1 and Tr2 in table 2.
p.4 Update part number of DI1 and DI2 from RB161VA-20 to RB161VAM-20TR.
p.4 Update part number of all ceramic capacitors in table 2.
p.5 Updated “DI2 and DI3 between output voltage and REG10”.
p.5 Updated Figure. 5 of snubber circuit.
p.6 to p.8 Updated Figure.6 to Figure.19.
p.8 Update “Board Layout”.
p.11 Update “Products listed in the Part list”.
5. Oct. 2023
005
p.1 Changed Unit degrees to ° .
p.1, p.2, p.3 Change Io to IOUT.
p.2 Change VIN=15.0V to 36V, VOUT=12.0V to VIN=15V to 36V, VOUT=12V.
p.2 Changed schematic drawing. FB and INV connection changed.
p.4 RS of Table.2 is change from PMR100PZPXFU5L00 to PMR100HZPFU5L00.
p.4 Add comment. “Recommended parts are selected from those products and information
available at the time this user’s guide (Rev.004) was released. If supply conditions
change and parts are not available, use similar parts.”

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R2043A
The information contained in this document is intended to introduce ROHM Group (hereafter
referred to asROHM) products. When using ROHM products, please verify the latest specifications
or datasheets before use.
ROHM products are designed and manufactured for use in general electronic equipment and
applications (such as Audio Visual equipment, Office Automation equipment, telecommunication
equipment, home appliances, amusement devices, etc.) or specified in the datasheets. Therefore,
please contact the ROHM sales representative before using ROHM products in equipment or
devices requiring extremely high reliability and whose failure or malfunction may cause danger or
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expenses, or losses incurred by you or third parties arising from the use of ROHM Products for
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Electronic components, including semiconductors, can fail or malfunction at a certain rate. Please
be sure to implement, at your own responsibilities, adequate safety measures including but not
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The information contained in this document, including application circuit examples and their
constants, is intended to explain the standard operation and usage of ROHM products, and is not
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