JW®7719 is a synchronous rectifier, used for the secondary side rectification of Flyback. By driving an internal MOSFET, JW7719 is able to significantly improve the efficiency comparing with the conventional Diode rectifier. 
When JW7719 senses VDS of internal MOSFET less than -300mV, it turns on the internal MOSFET. Once the VSWS is greater than -10mV, JW7719 turns off the internal MOSFET.
JW7719 supports multiple operation modes, such as DCM, CrCM, CCM and Quasi-Resonant. By implementing the Joulwatt proprietary technology, JW7719 is able to handle CCM operation.