UC3844BDG Current-mode PWM controller 1 A, 12 - 30 V, 250 kHz, SO-14

UC3844B, UC3845B, UC2844B, UC2845B High Performance Current Mode Controllers

Description: 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 temperature compensated reference, high gain error amplifier, current sensing comparator, and a high current totem pole output ideally suited for driving a power MOSFET. Also included are protective features consisting of input and reference undervoltage lockouts each with hysteresis, cycle-by-cycle current limiting, a latch for single pulse metering, and a flip-flop which blanks the output off every other oscillator cycle, allowing output deadtimes to be programmed from 50% to 70%. These devices are available in an 8-pin dual-in-line and surface mount (SOIC-8) plastic package as well as the 14-pin plastic surface mount (SOIC-14). The SOIC-14 package has separate power and ground pins for the totem pole output stage. The UCX844B has UVLO thresholds of 16V (on) and 10V (off), ideally suited for off-line converters. The UCX845B is tailored for lower voltage applications having UVLO thresholds of 8.5V (on) and 7.6V (off).

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