AN6-206 - Fairchild Semiconductor

AN6-206 Primary-Side Synchronous Rectifier (SR) Trigger Solution

www.fairchildsemi.com AN-6206 Primary-Side Synchronous Rectifier (SR) Trigger Solution for Dual-Forward Converter Introduction In any switching converter, rectifier diodes are used to obtain DC output voltage. The conduction loss of diode rectifier contributes significantly to the overall power losses in a power supply; especially in low output voltage appl.

Features

o provides drive signal for the primary-side power switches by using an output signal from the PWM controller. FAN6210 can be combined with any PWM controller that can drive a dual-forward converter. To obtain optimal timing for the SR drive signals, transformer winding voltage is also monitored. To improve light-load efficiency, green-mode operation is employed, which disables the SR turn-on trigger signal, minimizing gate drive power consumption at light-load condition. This application note describes the design procedure of SR circuit using FAN6210 and FAN6206. The guidelines for printed ci.