Phase-shifted full-bridge controller with synchronous rectification

The UCC28950 enhanced phase-shifted controller builds upon Texas Instrument's industry standard UCCx895 phase-shifted controller family with enhancements that offer best in class efficiency in today's high-performance power systems. The device implements advanced control of the full-bridge along with active control of the synchronous rectifier output stage. The primary-side signals allow programmable delays to ensure ZVS operation over wide-load current and input voltage range, while the load current naturally tunes the secondary-side synchronous rectifiers switching delays, maximizing overall system efficiency. Available in TSSOP-24 package, the UCC28950 also offers multiple light-load management features including burst mode and dynamic SR on/off control when transitioning in and out of Discontinuous Current Mode (DCM) operation, ensuring ZVS operation is extended down to much lighter loads. In addition, the UCC28950 includes support for peak current along with voltage mode control, programmable switching frequency up to 1MHz and a wide set of protection features including cycle-by-cycle current limit, UVLO and thermal shutdown. A 90-degree phase-shifted interleaved synchronized operation can be easily arranged between two converters, says the company.