UC2845B

高性能电流模式控制器 HIGH PERFORMANCE CURRENT MODE CONTROLLERS

High Performance Current Mode Controllers

The UC3844B, UC3845B series are high performance fixed frequency current mode controllers. They are specifically designed for Off−Line and dc−dc converter applications offering the designer a cost−effective solution with minimal external components. These integrated circuits feature an oscillator, a temperaturecompensated reference, high gain error amplifier, current sensing comparator, and a high current totem pole output ideally suited for driving a power MOSFET.

Features

•Trimmed Oscillator for Precise Frequency Control

•Oscillator Frequency Guaranteed at 250 kHz

•Current Mode Operation to 500 kHz Output Switching Frequency

•Output Deadtime Adjustable from 50% to 70%

•Automatic Feed Forward Compensation

•Latching PWM for Cycle−By−Cycle Current Limiting

•Internally Trimmed Reference with Undervoltage Lockout

•High Current Totem Pole Output

•Undervoltage Lockout with Hysteresis

•Low Startup and Operating Current

•These Devices are Pb−Free and are RoHS Compliant

•NCV Prefix for Automotive and Other Applications Requiring Unique Site and Control Change Requirements; AEC−Q100

Qualified and PPAP Capable