The UCC2897 PWM controller simplifies implementation of the various active clamp/reset and synchronous rectifier switching power topologies.
Based on the UCC2891 active-clamp controller the UCC2897 is a peak current-mode, fixed-frequency, high-performance pulse width modulator. It includes the logic and the drive capability for the P-channel auxiliary switch along with a simple method of programming the critical delays for proper active clamp operation.
Features include an internal programmable slope compensation circuit, precise DMAX limit, and a synchronizable oscillator with an internal timing capacitor. An accurate line monitoring function also programs the converter's ON and OFF transitions with regard to the bulk input voltage.
The UCC2897 adds a second level hiccup mode current sense threshold, bi-directional synchronization and the input overvoltage protection functionalities that are not available on the 16-pin UCC2891. The UCC2897 is offered in 20-pin TSSOP (PW) and 20-pin QFN (RTJ) package.