Secondary-side MOSFET driver cuts costs in aux. 5-12V PSUs

July 13, 2016 // By Graham Prophet
The APR345 secondary-side MOSFET driver (Diodes Inc.) is positioned as the smallest available, lowest BOM cost solution for synchronous rectification in 5V to 12V power supplies.

This device is suitable for line-powered adapters and chargers for consumer products such as smartphones and tablets, PVRs and IPTV boxes, cable and xDSL modems, datacom equipment and other portable consumer/home appliances, providing power conversion for standby and auxiliary power supplies.


In conjunction with an external MOSFET, the APR345 driver provides synchronous secondary-side rectification control that supports various flyback circuit topologies operating in CCM, DCM and quasi-resonant modes. By sensing the external MOSFET’s drain-to-source voltage and driving the MOSFET to reduce the voltage drop, the APR345 reduces power dissipation and improves overall system efficiency. It is packaged in SOT26 and needs a minimum of external components; it is priced at $0.37 (1000).