The NCP81178 is a secondary-side synchronous rectifier driver designed for isolated power converters, especially actively clamped forward or flyback, and asymmetric half bridge converters. The NCP81178 drives two N-channel MOSFETs on the secondary side in a complementary manner. It accepts a PWM signal that can be derived from the secondary winding or an auxiliary winding on the main power transformer. It can also take a PWM from the primary side controller through a pulse transformer or other isolator.