This circuit configuration, which utilises an external MOSFET, allows for synchronous rectification in discontinuous conduction mode operation by sensing the MOSFET drain-to-source voltage and providing a periodic signal to drive the MOSFET when the output voltage is lower than a certain threshold. By responding quickly to the secondary side voltage, the controller can improve the transient response of the primary side control system and reduce the power dissipation of the secondary side rectifier.
The APR343, which is provided with over-voltage protection and under-voltage lockout, features a design that minimises external components and is offered in a SOT25 package, allowing it to meet the power converter requirements of consumer and home appliances.
The APR343 is available now, priced at $0.35 each and sold in 1,000-piece quantities.