The UC3842B, UC3843B series are high performance fixed frequency current mode controllers. They are specifically designed for OffLine and dctodc converter applications offering the designer a costeffective 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.