Rohm BD9F500QUZ-EVK-001 User manual

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© 2020 ROHM Co., Ltd. No. 63UG090E Rev.001
2020.12
User’s Guide
Switching Regulator Series
1ch Buck Converter with Integrated FET
BD9F500QUZ EVK
BD9F500QUZ-EVK-001 (12V→1V, 5A)
Introduction
This user's guide describes the steps required to operate the EVK of BD9F500QUZ. This document includes description
of peripheral components, operating instructions and reference data.
Description
BD9F500QUZ-EVK-001 uses BD9F500QUZ to output 1V from a 12V input voltage. The input voltage of the
BD9F500QUZ is from 4.5V to 36V and the output voltage is configurable from 0.6V to 14V with external resistors.
The operating frequency is selectable between 600 kHz, 1 MHz and 2.2 MHz. It is a fixed on-time controlled DC/DC
converter that provides fast transient response. The light-load mode control improves efficiency at light loads which
makes it ideal for devices that require less standby power. Built-in functions include variable soft start function which
prevents inrush current at startup, UVLO (Under Voltage Lock Out), TSD (Thermal Shutdown Detection), OCP (Over
Current Protection) and SCP (Short Circuit Protection).
Application
Step-down power supplies for SoCs, FPGAs, microprocessors, etc.
Printer (MFP / LBP / IJP / POS)
Office Equipment
Laptop PC
USB Type-C Applications
EVK Operating Limits
Parameter Min Typ Max Units Conditions
Input Voltage 4.5 12.0 36.0 V
Output Voltage 1.0 V
Maximum Output Current 5.0 A
Switching Frequency 1 MHz
Maximum Efficiency 81 % Io = 2A
UVLO Threshold Voltage 4.2 V VIN sweep up
UVLO Hysteresis Voltage 200 mV

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© 2020 ROHM Co., Ltd. No. 63UG090E Rev.001
2020.12
User’s Guide
BD9F500QUZ-EVK-001
EVK Overview
Figure 1. BD9F500QUZ-EVK-001 (Top View) Figure 2. BD9F500QUZ-EVK-001 (Bottom View)
EVK Schematic
Figure 3. BD9F500QUZ-EVK-001 Schematic
H
L

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© 2020 ROHM Co., Ltd. No. 63UG090E Rev.001
2020.12
User’s Guide
BD9F500QUZ-EVK-001
Operating Procedures
1. Turn off the DC power supply power switch and connect the power supply's GND terminal to the GND
terminal of the EVK.
2. Connect the positive terminal of the DC power supply to the VIN pin of the EVK.
3. Connect the load across the VOUT pin and the GND pin of the EVK. In the case of an electronic load, turn
the load off.
4. Connect the voltmeter's positive terminal to the EVK's VOUT_S and the GND terminal to the EVK's GND_S.
5. Connect the SW_EN jumper to H (VIN).
6. Turn on the DC power supply. Make sure that the voltmeter reading is 1V.
7. Turn on the electronic load.
(Caution) This EVK does not support hot plug. Do not perform hot plug test.
Operating State Settings
Select the status of BD9F500QUZ as shown in Table 1 according to the EN pin voltage.
Table 1. EN Pin Settings
EN Pin Voltage State
HIGH (≥ 1.2 V) Enable
LOW (≤ 1.1 V) Shutdown
Operating Mode Settings
The switching frequency of BD9F500QUZ is selected by SEL1 and SEL2 pins as shown in Table 2. This EVK is equipped
with optimum parts for 1MHz switching frequency, a maximum output current of 5A, and a light load mode. When
changing the operating frequency, it is necessary to change the parts.
Table 2．Switching Frequency Settings
SEL1
Condition
SEL2
Condition
Switching
Frequency
(Hz)
Maximum Output Current (A)
(I
O MAX
) Operation Mode
GND GND
1 MHz (Typ)
5 Light Load (LLM)
GND OPEN Fixed PWM
VREG GND 3 Light Load (LLM)
VREG OPEN Fixed PWM
OPEN GND
600 kHz (Typ)
5 Light Load (LLM)
OPEN OPEN Fixed PWM
GND VREG 3 Light Load (LLM)
OPEN VREG Fixed PWM
VREG VREG 2.2 MHz (Typ) 3 Fixed PWM

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© 2020 ROHM Co., Ltd. No. 63UG090E Rev.001
2020.12
User’s Guide
BD9F500QUZ-EVK-001
Parts List
Table 3. Parts List
Count Parts No. Type Value Description Manufacturerʼs
Part Number Manufacturer Configuration
(mm)
1 U1 IC - Single Synchronous
BUCK Converter BD9F500QUZ ROHM 3.0x 3.0
1 L1 Inductor 0.68µH 11A max, ±20% FDSD0518-H-R68M Murata 5249
0 C0
Aluminum
Electrolytic
Capacitor
No mount N/A N/A N/A Φ10
1 C1 Ceramic
Capacitor 0.1μF 50V, X5R, ±10% UMK105BJ104KV-F TAIYO YUDEN 1005
1 C2 Ceramic
Capacitor 10μF 50V, X5R, ±20% UMK325BJ106MM-P TAIYO YUDEN 3225
0 C3 Ceramic
Capacitor No mount N/A N/A N/A 3225
1 C4 Ceramic
Capacitor 22μF 25V, X5R, ±20% TMK212BBJ226MG-TT TAIYO YUDEN 2012
1 C5 Ceramic
Capacitor 22μF 25V, X5R, ±20% TMK212BBJ226MG-TT TAIYO YUDEN 2012
0 C6 Ceramic
Capacitor No mount N/A N/A N/A 1608
0 C7
Aluminum
Electrolytic
Capacitor
No mount N/A N/A N/A Φ10
1 C8 Ceramic
Capacitor 0.1μF 50V, X5R, ±10% UMK105BJ104KV-F TAIYO YUDEN 1005
0 C9 Ceramic
Capacitor No mount N/A N/A N/A 1005
1 C10 Ceramic
Capacitor 2.2μF 25V, X5R, ±20% TMK105CBJ225MV-F TAIYO YUDEN 1005
1 C11 Ceramic
Capacitor 27pF 50V, C0G, ±5% GRM035C1H270JA01 Murata 1005
0 C12 Ceramic
Capacitor No mount N/A N/A N/A 1005
0 C13 Ceramic
Capacitor No mount N/A N/A N/A 1005
1 R0 Resistor 0Ω Jumper MCR01MZPJ000 ROHM 1005
1 R1 Resistor 0Ω Jumper MCR01MZPJ000 ROHM 1005
1 R2 Resistor 180kΩ 50V, ±1%, 1/16W MCR01MZPF1803 ROHM 1005
1 R3 Resistor 270kΩ 50V, ±1%, 1/16W MCR01MZPF2703 ROHM 1005
1 R4 Resistor 0Ω Jumper MCR01MZPJ000 ROHM 1005
0 R5 Resistor No mount N/A N/A N/A 1005
1 R6 Resistor 0Ω Jumper MCR01MZPJ000 ROHM 1005
1 R7 Resistor 100kΩ 50V, ±1%, 1/16W MCR01MZPF1003 ROHM 1005
0 R8 Resistor No mount N/A N/A N/A 1005
0 R9 Resistor No mount N/A N/A N/A 1005
1 R10 Resistor 0Ω Jumper MCR01MZPJ000 ROHM 1005

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© 2020 ROHM Co., Ltd. No. 63UG090E Rev.001
2020.12
User’s Guide
BD9F500QUZ-EVK-001
Parts List – Cont’d
Table 3. Parts List
Count Parts No. Type Value Description Manufacturerʼs
Part Number Manufacturer Configuration
(mm)
0 R11 Resistor No mount N/A N/A N/A 1005
1 R12 Resistor 0Ω Jumper MCR01MZPJ000 ROHM 1005
1 R13 Resistor 0Ω Jumper MCR01MZPJ000 ROHM 1005
0 R14 Resistor No mount N/A N/A N/A 1005
1 SW_EN - - - 1x3 Header Connection,
Pitch 2.54 N/A -
11
VIN, VIN_S, VOUT,
VOUT_S, GND,
GND_S, EN,
SW, PGD, V_EXT
Test Pin - - ST-2-2 MAC8 -

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© 2020 ROHM Co., Ltd. No. 63UG090E Rev.001
2020.12
User’s Guide
BD9F500QUZ-EVK-001
EVK PCB Layout
EVK PCB Information
Number of Layers Material Board Size Copper Thickness
4 FR-4 85mm x 85mm x 1.6mmt 2oz (70μm) *Top, Bottom Layer
1oz (35μm) *Middle Layers
Figure 4. Top Layer Layout Figure 5. Middle1 Layer Layout
(Top View) (Top View)
Figure 6. Middle2 Layer Layout Figure 7. Bottom Layer Layout
(Top View) (Top View)

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© 2020 ROHM Co., Ltd. No. 63UG090E Rev.001
2020.12
User’s Guide
BD9F500QUZ-EVK-001
Reference Application Curves
Ta = 25℃, VIN = 12V, EN = VIN, unless otherwise specified
Figure 8. Current Consumption vs VIN
(I
O
= 0mA)
Figure 10. Line Regulation
(I
O
= 0mA)
Figure 9. Shutdown Current vs VIN
(EN=GND)
Figure 11. Load Regulation
0
200
400
600
0 5 10 15 20 25 30 35 40
IIN[μA]
VIN[V]
0.0
0.5
1.0
1.5
0 5 10 15 20 25 30 35
VOUT[V]
VIN[V]
0
2
4
6
8
10
0 5 10 15 20 25 30 35 40
IIN[μA]
VIN[V]
0.96
0.98
1
1.02
1.04
012345
VOUT[V]
I
O
[A]

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© 2020 ROHM Co., Ltd. No. 63UG090E Rev.001
2020.12
User’s Guide
BD9F500QUZ-EVK-001
Reference Application Curves – Cont’d
Figure 12. Switching Frequency vs VIN
(I
O
= 1A)
Figure 14. Load Response
Figure 13. Efficiency vs Load Current
Figure 15. Frequency Response
(I
O
= 5A)
0
500
1000
1500
0 5 10 15 20 25 30 35
Frequency[kHz]
VIN[V]
0
20
40
60
80
100
0.001 0.01 0.1 1 10
Efficiency[%]
I
O
[A]

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© 2020 ROHM Co., Ltd. No. 63UG090E Rev.001
2020.12
User’s Guide
BD9F500QUZ-EVK-001
Reference Application Curves – Cont’d
Figure 16. Start Up Waveform
(I
O
= 1A)
Figure 17. Shutdown Waveform
(I
O
= 1A)

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© 2020 ROHM Co., Ltd. No. 63UG090E Rev.001
2020.12
User’s Guide
BD9F500QUZ-EVK-001
Revision History
Date Revision
Number Description
2020.12.17 001 Initial release