The MC44608 is a high performance voltage mode controller designed for off--line converters. This high voltage circuit that integrates the startup current source and the oscillator capacitor, requires few external components while offering a high flexibility and reliability.
The device also features a very high efficiency standby management consisting of an effective Pulsed Mode operation. This technique enables the reduction of the standby power consumption to approximately 1.0 W while delivering 300 mW in a 150 W SMPS.

General Features
• Integrated Startup Current Source
• Lossless Off--Line Startup
• Direct Off--Line Operation
• Fast Startup
• Flexibility
• Duty Cycle Control
• Undervoltage Lockout with Hysteresis
• On Chip Oscillator Switching Frequency 40 or 75
• Secondary Control with Few External Components
• These are Pb--Free Devices*

Protections
• Maximum Duty Cycle Limitation
• Cycle by Cycle Current Limitation
• Demagnetization (Zero Current Detection) Protection
• “Over VCC Protection” Against Open Loop
• Programmable Low Inertia Over Voltage Protection Against Open Loop
• Internal Thermal Protection

SMPS Controller
• Pulsed Mode Techniques for a Very High Efficiency Low Power Mode
• Lossless Startup
• Low dV/dT for Low EMI Radiations