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4.5V to 18V Input, 3.0A Integrated MOSFET 1ch Synchronous Buck DC/DC Converter - BD9C301FJ-LB(H2)

This is the product guarantees long time support in Industrial market. BD9C301FJ is a synchronous buck switching regulator with built-in low on-resistance power MOSFETs. With wide input voltage range, It is capable of providing current of up to 3 A. It is a current mode control DC/DC converter and features high-speed transient response. Phase compensation can also be set easily.

Technical Documents

White Paper

White Paper
Industrial DC/DC Buck Converters BD9x Series

User's Guide

Evaluation Board User's Guide
BD9C301FJ Evaluation Board User's Guide
Evaluation Board Data
Gerber, Schematic, Board Layout, BoM, etc.

Application Note

Reference Circuits and Bomlist
Reference Circuits and Bomlist
PCB Layout Techniques of Buck Converter
Major problems that arise from in appropriate layout may cause increase in noise superposed by output and switching signal, the deterioration of regulator, and also lack of stability...
Phase Compensation Design for Current Mode Buck Converter
This application note explains the method used by ROHM for designing the phase compensation for current mode buck converters.
Method for Determining Constants of
This application note explains the procedures for determining the constants of peripheral parts of a buck DC/DC converter.
Bootstrap Circuit in the Buck Converter
This application note explains the step-up circuit using a bootstrap capacitor. In buck converters, this circuit is used when the highside switch is the N-ch MOSFET.
Measurement Method for Phase Margin with Frequency Response Analyzer (FRA)
This application note introduces a method for easily measuring the phase margin with a Frequency Response Analyzer (FRA) made by NF Corporation.
Usage of SPICE Macromodel for DC/DC
This application note explains how to install SPICE macromodels and how the circuit symbols are configured.
Snubber Circuit for Buck Converter IC
In buck converter ICs, many high-frequency noises are generated at switch nodes. A snubber circuit provides one way of eliminating such harmonic noise. This application note explains how to set up the RC snubber circuits.
Efficiency of Buck Converter
This application note explains power loss factors and methods for calculating them. It also explains how the relative importance of power loss factors depends on the specifications of the switching power source.
Calculation of Power Loss (Synchronous)
This application note describes how to obtain the power loss required to calculate the temperature of a semiconductor device. Temperature control is important to ensuring product reliability.
Thermal Resistance
The definition and how to use thermal resistance and thermal characterization parameter of packages for ROHM’s integrated circuit are described in this application note.
Inductor Calculation for Buck converter IC
This application note covers the steps required in choosing the inductor and to calculate the value used in buck regulator IC circuits.
Considerations for Power Inductors Used for Buck Converters
This application note explains the features and things to consider when shopping for power inductors.
Capacitor Calculation for Buck converter IC
This application note explains the calculation of external capacitor value for buck converter IC circuit.
The Important Points of Multi-layer Ceramic Capacitor Used in Buck Converter circuit
Using unmatched MLCC may not obtain required target characteristics for power supply circuit and may cause abnormal operation. This application note explains the important points while using MLCC.
Resistor Value Table to set Output Voltage of Buck Converter IC
This Application Note offers reference table to easily set resistor values for output voltage with various internal reference voltages VREF.
Part Explanation
For ICs

Design Model

Spice Model

Additional information Batch Download 

Package Information

Package Information
Package Structure, Packing Specification, Footprint dimensions, Marking Specification, Storage conditions, Soldering conditions
Anti-Whisker formation

Environmental Data

UL94 Flame Classifications of Mold Compound
Compliance with the ELV directive
REACH SVHC Non-use Declaration
RoHS Comission Delegated Directive

Export Information

The Export Control Order
Export Administration Regulations(EAR)


Factory Information