JW®7715 is a synchronous rectifier controller, used for the secondary side rectification of Flyback. By driving an external MOSFET, JW7716 is able to significantly improve the efficiency comparing with the conventional Diode rectifier. 
When JW7716 senses Vds of MOSFET less than -300mV, it turns on the MOSFET. Once the Vds is greater than -10mV, JW7716 turns off the MOSFET.
JW7716 supports multiple operation modes, such as DCM, CrCM, CCM and Quasi-Resonant. By implementing the Joulwatt proprietary technology, JW7716 is able to handle CCM operation.