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© 2020 ROHM Co., Ltd.
No. 63UG041E Rev.001
AUG.2020
User’s Guide
Switching Regulator Series
Buck Converter with Integrated FET
BD9B304QWZ EVK
BD9B304QWZ-EVK-001 (5.0V
→
1.2V, 3.0A)
Introduction
This user’s guide will provide the necessary steps to operate the EVK of ROHM’s BD9B304QWZ 1channel Buck DC/DC converter.
This include the external parts, operating procedures and application data.
Description
This EVK was developed for ROHM’s synchronous buck DC/DC converter BD9B304QWZ. The BD9B304QWZ accepts a power
supply input range of 2.7V to 5.5V, and generates an output voltage from 0.8V to 0.8 x V
IN
using external resistors. It has a built-
in 40mΩ N-channel MOSFET for High side and Low Side that is operating frequency is 1.0MHz/2.0MHz selectable. It adopts a
Deep-SLLM compliant fixed on-time control method that consumes low current at light loads, making it ideal for equipment that
wants to reduce standby power consumption. It has a fixed 1ms soft start function to prevent rush current at startup, UVLO
(Under Voltage Lock Out), TSD (Thermal Shutdown Detection), OCP (Over Current Protection), SCP (Short Circuit Protection)
functions.
Application
Step-down power supply for DSP, FPGA, microprocessor, etc.
Laptop PC/Tablet PC/Server
LCD TV
Storage device (HDD/SSD)
Printers and OA equipment
Distribution power supply, secondary power supply
EVK Operating Limits
Parameter
Min
Typ
Max
Units
Conditions
Input Voltage
2.7
5.0
5.5
V
Output Voltage
1.2
V
Output Current Range
3.0
A
Operating Frequency
1.0
MHz
By VIN applying to FREQ
pin.
Maximum Efficiency
88
%
I
O
= 1A
UVLO Detect Voltage
2.450
V
VIN sweep down
UVLO Release Voltage
2.550
V
VIN sweep up
