Built around the BD7F105EFJ-C flyback converter, the REF67006 reference design generates an isolated 16.5V output from an 8V–32V input, helping engineers accelerate automotive and industrial power supply development with complete design resources.
Designing isolated low-power supplies for automotive electronics requires balancing efficiency, safety, compactness, and wide input-voltage tolerance. Auxiliary power rails used in body electronics, industrial controllers, battery management systems (BMS), and communication modules must continue operating reliably despite battery voltage fluctuations, electrical noise, and transient conditions. Addressing these challenges, ROHM’s REF67006 reference design demonstrates an automotive-qualified isolated flyback DC-DC converter capable of generating a regulated 16.5V output from an 8V to 32V DC input, making it suitable for 12V automotive power architectures.
The reference design is built around the BD7F105EFJ-C isolated flyback converter IC and is implemented on the BD7F105EFJ-EVK-001 evaluation board. It delivers up to 0.25A output current, providing a maximum output power of approximately 4W when powered from a 12V input. This output capability makes the design suitable for powering isolated communication interfaces, gate drivers, sensor modules, and other auxiliary circuits that require galvanic isolation while maintaining a compact footprint.
One of the key advantages for hardware designers is the wide operating input range. Supporting 8V to 32V DC allows the converter to tolerate common automotive battery conditions, including cold-crank voltage drops and load-dump variations. The design achieves a typical efficiency of around 80% at a 2W load, helping reduce thermal dissipation while maintaining reliable operation in space-constrained embedded systems. Typical standby power consumption is only 40mW, making it suitable for applications that remain active during vehicle standby or low-power operating modes.
Beyond the hardware itself, REF67006 provides a complete development platform for accelerating power supply implementation. ROHM supplies comprehensive design resources including the complete circuit schematic, PCB layout files, bill of materials (BOM), and evaluation board documentation. These resources allow engineers to analyse transformer selection, feedback implementation, isolation techniques, EMI considerations, and PCB routing practices before adapting the design to their own applications. Having access to production-oriented design files can significantly reduce prototype iterations and shorten development time.
The reference design also incorporates recommended peripheral components such as Schottky barrier diodes and Zener diodes selected to complement the BD7F105EFJ-C controller. Engineers can therefore evaluate not only the controller performance but also the complete power stage, component selection strategy, and overall converter behaviour under realistic operating conditions.
REF67006 is applicable across a broad range of automotive and industrial systems requiring compact isolated power conversion. Typical use cases include battery management systems, industrial PLCs, factory automation equipment, automotive communication modules, isolated sensor interfaces, gate driver supplies, instrumentation, and embedded control systems. By combining an automotive-grade isolated flyback controller with ready-to-use hardware and open design resources, the reference design offers an efficient starting point for engineers developing reliable low-power isolated DC-DC converters while reducing design risk and speeding product development.
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