1• 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-byCycle 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
2 Applications
• High-Efficiency DC-to-DC Power Supplies
• Server Power, 48-V Telecom, Datacom, and 42-V Automotive Applications
3 Description
The UCC2897APW PWM controller simplifies implementation of the various active clamp or reset and synchronous rectifier switching power topologies.
The UCC2897APW is a peak current-mode fixedfrequency 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 UCC2897APW adds a second-level hiccup-mode current-sense threshold, bi-directional synchronization and input-overvoltage protection functionalities. The UCC2897APW is offered in 20-pin TSSOP (PW) and 20-pin QFN (RGP) packages.
Feature
- Low-output jitter
- Soft-stop shutdown of MAIN and AUX
- 110-V input startupfunction
- Ideal for active-clamp, reset-forward, flyback and synchronousrectifier uses
- Provides complementary auxiliary driver with programmable deadtime (Turn-On Delay) between AUX and MAIN switches
- Peak current-mode controlwith 0.5-V cycle-by-cycle current limiting
- TrueDrive? 2-A Sink, 2-A source outputs
- Trimmedinternal-bandgap reference for accurate line UV and line OVthreshold
- Programmable slope compensation
- High-performance1-MHz synchronizable oscillator with internal timing capacitor
- Preciseprogrammable maximum duty cycle
- PB-free lead finishpackage
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DescriptionThe 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.
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.
