The UCC28951 device is an enhanced version of the UCC28950. It is a fully compatible drop-in replacement for the UCC28950. Refer to application note SLUA853 to determine which controller to use. The UCC28951 uses advanced control of the full-bridge in addition to active control of the synchronous rectifier (SR) output stage.
Programmable delays ensure ZVS operation over a wide range of operating conditions, while the load current naturally tunes the switching delays of the secondary-side synchronous rectifiers(SR). This functionality maximizes overall system efficiency.
The UCC28951 has many light-load management features including burst-mode operation and dynamic SR ON and OFF control during transition into and out of discontinuous current mode (DCM) operation. The device operates in current-mode or voltage-mode control. The switching frequency can be programmed up to 1 MHz. The device has protection features including cycle-by-cycle current limit, UVLO, and thermal shutdown.
The 24-pin, TSSOP package complies with RoHS requirements .