The BD9x family of buck DC-DC converters

Product Overview

ROHM developed the BD9x family of buck DC-DC converters to meet the various requirements of DC-DC converter applications. From the matrix of input voltage and output current, users can easily find the ideal power supply solution to fit set needs. The optimum product can also be selected based on high-speed response control, light load mode, and other characteristics.

Samples can be purchased online through authorized distributors, along with evaluation boards that make it possible to immediately verify operation.


The BD9x series includes of a range of models to meet customer needs.

[Synchronous/Asynchronous Rectification]

A wide variety of both asynchronous types (with no external diode needed) and high-efficiency synchronous rectification models are offered that cover the entire voltage range.

[Fast Transient Response with Current Mode and H3RegTM Control]

Current-mode operation offers faster transient response characteristics than conventional voltage-mode control. In addition, phase compensation can easily be set and output ripple further reduced. The lineup also includes units that utilize hysteresis control to provide faster transient response than current mode and that do not require phase compensation.

[Improved Efficiency at Light Loads]

Light load mode reduces the operating current when the load current decreases and the switching frequency remains low, improving efficiency.

[Thin, Compact Package with Superior Heat Dissipation]

An exposed pad enables high efficiency heat dissipation from the backside of the package to the PCB, making it possible to achieve a 6A DC-DC solution in a compact form factor.

[Support for Small Lots]

Part numbers ending with -LB are designed for industrial equipment requiring long-term supply and superior reliability. They are available in smaller reels in order to eliminate waste and excess inventory during smaller production runs.