EVLSRK1000B-TO SRK1000B adaptive synchronous rectification controller for flyback

The EVLSRK1000B-TO is a demonstration board, designed for evaluation of the SRK1000B synchronous rectification controller.

The SRK1000B implements a control scheme specific for secondary-side synchronous rectification in flyback converters and provides high-current gate-drive outputs for driving N-channel power MOSFET.

The device can operate both in quasi-resonant applications and in fixed frequency (FF) mixed DCM-CCM applications. The board is provided with a setting suitable for QR applications. To use in FF applications, a 100 pF capacitor needs to be added in C4. A 68 kΩ resistor (R5) is provided on the TON pin that fixes the blanking after the turn-on to about 0.8 μs.

The board includes the SR MOSFET (TO-220FP package) and can be easily implemented into an existing converter to substitute rectifier diodes.