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.
Also included are protective features consisting of a high speed fault
comparator, programmable soft–start circuitry, input undervoltage lockout
with selectable thresholds, and reference undervoltage lockout.
These devices are available in dual–in–line and surface mount packages.
• 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