Click to expand full text
April 1997
ML4813* Flyback Power Factor Controller
GENERAL DESCRIPTION
The ML4813 is a PWM controller designed for use in a discontinuous "flyback" or "buck-boost" type power factor correction (PFC) system for low power, low cost applications. The circuit includes a precision reference, oscillator, error amplifier, over-voltage comparator, over-current comparator, and an extra op-amp as well as a high current output. In addition, start-up is simplified by an under-voltage lockout circuit. In a typical application, the ML4813 functions as a voltage mode regulator. By maintaining a constant duty cycle, the current follows the input voltage, making the impedance of the entire circuit appear purely resistive. With the flyback circuit, power factors of 0.
ML4813 Datasheet
