UCC2897

电流模式有源钳位 PWM 控制器

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

Based on the UCC2891 active-clamp controller the UCC2897 is a peak current-mode, fixed-frequency, high-performance pulse width modulator. It 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 converter"s ON and OFF transitions with regard to the bulk input voltage.

The UCC2897 adds a second level hiccup mode current sense threshold, bi-directional synchronization and the input overvoltage protection functionalities that are not available on the 16-pin UCC2891. The UCC2897 is offered in 20-pin TSSOP PW and 20-pin QFN RTJ package.

.

Ideal for Active Clamp/Reset Forward, Flyback and Synchronous Rectifier Apps

.

Provides Complementary Auxiliary Driver with Programmable Deadtime Turn-On Delay between AUX and MAIN Switches

.

Peak Current-Mode Control with 0.5-V Cycle-by-Cycle Current Limiting

.

Hiccup Mode 0.75-V Current Limit

.

TrueDrive™ 2-A Sink, 2-A Source Outputs

.

110-V Input Startup Device

.

Trimmed Internal Bandgap Reference for Accurate Line UV and Line OV Threshold

.

Programmable Slope Compensation

.

High-Performance 1.0-MHz Synchronizable Oscillator with Internal Timing Capacitor

.

Precise Programmable Maximum Duty Cycle

.

PB-Free Lead Finish Package

.

APPLICA ONS

.

High-Efficiency DC/DC Power Supplies

.

Server Power, 48-V Telecom, Datacom, and 42-V Automotive Applications