ROHM Launches "PFC + Flyback Control Reference Design" to Enable More Compact Power Supplies

ROHM has developed a new reference design, 'REF67004', which utilizes a single microcontroller to control both a current critical mode Power Factor Correction (PFC) converter and a quasi-resonant flyback converter—topologies widely used in consumer electronics and industrial equipment power supplies.

This design integrates ROHM's analog power stage circuitry, built with Si MOSFETs and a gate driver IC, with a digitally controlled power circuit centered around the low-power LogiCoA™ microcontroller. This fusion creates ROHM's 'LogiCoA™ Power Solution.'

REF67004 incorporates a calibration function that compensates for characteristic variances in external components, allowing the LogiCoA™ microcontroller to precisely execute voltage settings and overcurrent protection. This enables designers to reduce design margins, select smaller, lower-power components and inductors, and ultimately shrink the power supply's footprint and cost.

Furthermore, REF67004 features a data logging function that saves operational records—such as input/output voltage/current and temperature—as well as pre-shutdown status and cumulative operating time to the non-volatile memory inside the LogiCoA™ microcontroller. Analyzing this data simplifies root cause analysis for power supply failures. Various control parameters and operational logs can be easily configured and retrieved from a PC via UART using example programs for the power control OS 'RMOS' available on ROHM's website.