The UCC2891D is a current-mode active clamp Pulse Width Modulation (PWM) Controller designed to simplify implementation of the various active clamp/reset switching power topologies. It is a peak current-mode, fixed frequency, high-performance pulse width modulator. It includes the logic and the drive capability for the auxiliary switch with a simple method of programming the critical delays for proper active clamp operation. It includes a 110V start-up regulator for initial start-up and to provide keep-alive power during stand-by. Additional features include an internal programmable slope compensation circuit, precise DMAX limit and a single resistor programmable synchronizable oscillator. An accurate line monitoring function also programs the converter"s ON and OFF transitions with regard to the bulk input voltage.
● Low output jitter
● Soft-stop shutdown of MAIN and AUX
● Ideal for active clamp/reset forward, flyback converters
● Peak current-mode control with cycle-by-cycle current limiting
● Accurate line UV and line OV threshold
● Programmable slope compensation
● Precise programmable maximum duty cycle
● Programmable soft-start
● Green product and no Sb/Br
●Device has limited built-in ESD protection, leads should be shorted together or the device placed in conductive foam during storage or handling to prevent electrostatic damage to the MOS gates.
