The MC44608 is a high performance voltage mode controller designed for off–line converters. This high voltage circuit that integrates the start–up 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 stand–by management consisting of an effective Pulsed Mode operation. This technique enables the reduction of the stand–by power consumption to approximately 1W while delivering 300mW in a 150W SMPS.


•Integrated Start–Up Current Source
•Lossless Off–Line Start–Up
•Direct Off–Line Operation
• Fast Start–Up

General Features

•Flexibility
•Duty Cycle Control
•Undervoltage Lockout with Hysteresis
• On Chip Oscillator Switching Frequency 40, or 75kHz
•Secondary Control with Few External Components 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 GreenLineController
•Pulsed Mode Techniques for a Very High Efficiency Low Power Mode
•Lossless Startup
•Low dV/dT for Low EMI Radiations