UCC24630 Synchronous Rectifier Controller

Texas Instruments' UCC24630 synchronous rectifier controller is a high-performance controller and driver for N-channel MOSFET power devices used for secondary-side synchronous rectification. The combination of controller and MOSFET emulates a near-ideal diode rectifier. This solution not only directly reduces power dissipation of the rectifier but also reduces primary-side losses as well, due to compounding of efficiency gains.

Utilizing a volt-second balancing control method, the UCC24630 is ideal for flyback power supplies over a wide-output voltage range since the device is not connected directly to the MOSFET drain. The synchronous rectifier drive turn-off threshold is not dependent on the MOSFET R_DS(on) which allows optimizing for maximum conduction time. Also secondary current ringing due to device and layout inductance does not affect the SR turn-off threshold.