The UC3842A, UC3843A series of high performance fixed frequency current mode controllers are specifically designed for offline and dctodc converter applications offering the designer a cost effective solution with minimal external components. These integrated circuits feature a trimmed oscillator for precise duty cycle control, 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, cyclebycycle current limiting, programmable output deadtime, and a latch for single pulse metering. These devices are available in an 8pin dualinline plastic package as well as the 14pin plastic surface mount (SO14). The SO14 package has separate power and ground pins for the totem pole output stage. The UCX842A has UYLO thresholds of 16 V (on) and 10 V (off), ideally suited for offline converters. The UCX843A is tailored for lower voltage applications having UVLO thresholds of 8.5 V (on) and 7.6 V (off). Trimmed Oscillator Discharge Current for Precise Duty Cycle Control