Small-outline synchronous rectification MOSFET driver for off-line power adapters

Diodes Incorporated offers their new the APR346 Secondary Side Synchronous Rectification MOSFET Driver, providing increased efficiency for off-line power adapters providing 5V to 20V DC from an AC supply. Designed to operate in CCM, DCM and QR mode, the APR346 is used to drive an external MOSFET to deliver the benefits of SR, which gives significantly higher performance and efficiency than diode-based secondary side rectification. SR is now favoured by power adapter manufacturers and is assumed to form the basis of power adapters for mobile phones, notebooks and a range of other portable devices, many of which will be adopting the USB Type-C connector with PD capabilities. The device needs very few extra components and, because it is intended to operate with an external MOSFET, it allows maximum design flexibility. With fast turn-on and turn-off times of 70ns and 100ns (typical) respectively, it delivers high performance through directly sensing the Drain-Source voltage of the external MOSFET and swiftly turning the MOSFET on or off according to need from the load. A built-in minimum on-time of 1.6µs (typical) effectively blanks out any potential Drain voltage ringing to maintain efficient operation as the load current begins to flow through the channel.