The MC34065H,L series are high performance, fixed frequency, dual current mode controllers. They 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 unique oscillator for precise duty cycle limit and frequency control, a temperature compensated reference, two high gain error amplifiers, two current sensing comparators, Drive Output 2 Enable pin, and two high current totem pole outputs ideally suited for driving power MOSFETs. Also included are protective features consisting of input and reference undervoltage lockouts each with hysteresis, cyclebycycle current limiting, and a latch for single pulse metering of each output. These devices are available in dualinline and surface mount packages. The MC34065H has UVLO thresholds of 14 V (on) and 10 V (off), ideally suited for offline converters. The MC34065L is tailored for lower voltage applications having UVLO thresholds of 8.4 V (on) and 7.8 V (off). Unique Oscillator for Precise Duty Cycle Limit and Frequency Control