The MC34067/MC33067 are high performance zero voltage switch resonant mode controllers designed for off–line and dc–to–dc converter applications that utilize frequency modulated constant off–time or constant deadtime control. These integrated circuits feature a variable frequency  oscillator, a precise retriggerable one–shot timer, temperature compensated reference, high gain wide bandwidth error amplifier, steering flip–flop, and dual high current totem pole outputs ideally suited for driving power MOSFETs.

•Zero Voltage Switch Resonant Mode Operation
•Variable Frequency Oscillator with a Control Range Exceeding 1000:1
•Precision One–Shot Timer for Controlled Off–Time
•Internally Trimmed Bandgap Reference
•4.0 MHz Error Amplifier
•Dual High Current Totem Pole Outputs
•Selectable Undervoltage Lockout Thresholds with Hysteresis
•Enable Input
•Programmable Soft–Start Circuitry
•Low Startup Current for Off–Line Operation