text.skipToContent text.skipToNavigation


Advanced Current-Mode Active Clamp PWM Controller


Package | PIN: PW | 20
Temp: Q (-40 to 125)
Carrier: Cut Tape
Qty Price
1-9 $2.55
10-24 $2.29
25-99 $2.13
100-249 $1.87
250-499 $1.75
500-749 $1.49
750-999 $1.26
1000+ $1.20


  • 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

All trademarks are the property of their respective owners.

Texas Instruments  UCC2897APWR

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

The UCC2897A is a peak current-mode fixed-frequency high-performance pulse-widthmodulator. The controller includes the logic and the drive capability for the P-channel auxiliaryswitch along with a simple method of programming the critical delays for proper active-clampoperation.

Features include an internal programmable slope compensation circuit, preciseDMAX limit, and a synchronizable oscillator with an internal-timingcapacitor. An accurate line-monitoring function also programs the ON and OFF transitions of theconverter with regard to the bulk input voltage, VIN.

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