UCC28250 (ACTIVE) Advanced PWM Controller with Pre-Bias Operation

The UCC28250 PWM controller is designed for high power density applications that may have stringent prebiased start-up requirements. The integrated synchronous rectifier control outputs target high-efficiency and high-performance topologies such as half-bridge, full-bridge, interleaved forward, and push-pull. The UCC27200 half-bridge drivers and UCC2732X MOSFET drivers used in conjunction with the UCC28250 provide a complete power converter solution.

Externally programmable soft-start, used in conjunction with an internal prebiased start-up circuit, allows the controller to gradually reach a steady-state operating point under all output conditions. The UCC28250 can be configured for primary or secondary-side control and either voltage or current mode control can be implemented.

The oscillator operates at frequencies up to 2 MHz, and can be synchronized to an external clock. Input voltage feedforward, cycle-by-cycle current limit, and a programmable hiccup timer allow the system to stay within a safe operation range. Input voltage, output voltage and temperature protection can be implemented. Dead time between primary-side switch and secondary-side synchronous rectifiers can be independently programmed.