ML4812 Datasheet – Power Factor Controller ( PDF )

Part Number: ML4812

Function: Power factor controller

Package: DIP 16, PLCC 20 Pin Type

Manufacturer: Fairchild Semiconductor


ML4812 datasheet



The ML4812 is designed to optimally facilitate a peak current control boost type power factor correction system. Special care has been taken in the design of the ML4812 to increase system noise immunity. The circuit includes a precision reference, gain modulator, error amplifier, over voltage protection, ramp compensation, as well as a high current output. In addition, start-up is simplified by an under voltage lockout circuit with 6V hysteresis. In a typical application, the IC functions as a current mode regulator. The current which is necessary to terminate the cycle is a product of the sinusoidal line voltage times the output of the error amplifier which is regulating the output DC voltage. Ramp compensation is programmable with an external resistor, to provide stable operation when the duty cycle exceeds 50%.


• Precision buffered 5V reference (±0.5%)
• Current-input gain modulator reduces external components and improves noise immunity
• Programmable ramp compensation circuit
• 1A peak current totem-pole output drive
• Overvoltage comparator helps prevent output voltage “runaway”
• Wide common mode range in current sense comparators for better noise immunity
• Large oscillator amplitude for better noise immunity

Other data sheets are available within the file: ML4812CP, ML4812CQ

ML4812 Datasheet PDF Download

ML4812 pdf