• Low-Output Jitter
• Soft-Stop Shutdown of MAIN and AUX
• 110-V Input Startup Function
• Ideal for Active-Clamp, Reset-Forward, Flyback and Synchronous Rectifier Uses
• Provides Complementary Auxiliary Driver with Programmable Dead Time (Turn-On Delay) between AUX and MAIN Switches
• Peak Current-Mode Control with 0.5-V Cycle-by-Cycle Current Limiting
• TrueDrive™ 2-A Sink, 2-A Source Outputs
• Trimmed Internal-Bandgap Reference for Accurate Line UV and Line OV Threshold
• Programmable Slope Compensation
• High-Performance 1-MHz Synchronizable Oscillator with Internal Timing Capacitor
• Precise Programmable Maximum Duty Cycle
• PB-Free Lead Finish Package

• High-Efficiency DC-to-DC Power Supplies
• Server Power, 48-V Telecom, Datacom, and 42-V Automotive Applications

The UCC2897A PWM controller simplifies implementation of the various active clamp or reset and synchronous rectifier switching power topologies.

The UCC2897A is a peak current-mode fixed-frequency high-performance pulse-width modulator. The controller 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 ON and OFF transitions of the converter with regard to the bulk input voltage, VIN.

The UCC2897A adds a second-level hiccup-mode current-sense threshold, bi-directional synchronization and input-overvoltage protection functionalities. The UCC2897A is offered in 20-pin TSSOP (PW) and 20-pin QFN (RGP) packages.