By Diodes Incorporated 26
Diodes' ZXGD3105N8 synchronous controller is designed for driving a MOSFET as an ideal rectifier. This replaces a diode for increasing the power transfer efficiency.
The device is comprised of a differential amplifier detector stage and high current driver. The detector monitors the reverse voltage of the MOSFET such that if body diode conduction occurs, a positive voltage is applied to the MOSFET's Gate pin. Once the positive voltage is applied to the Gate the MOSFET switches on allowing reverse current flow. The detectors' output voltage is then proportional to the MOSFET Drain-Source voltage and this is applied to the Gate, via the driver. This action provides a rapid MOSFET turn off as the Drain current decays to zero.