The MC34067/MC33067 are high performance zero voltage switch resonant mode controllers designed for offline and dctodc converter applications that utilize frequency modulated constant offtime or constant deadtime control. These integrated circuits feature a variable frequency oscillator, a precise retriggerable oneshot timer, temperature compensated reference, high gain wide bandwidth error amplifier, steering flipflop, and dual high current totem pole outputs ideally suited for driving power MOSFETs.