GENERAL DESCRIPTION

The ML4824 is a controller for power factor corrected, switched mode power supplies. Power Factor Correction (PFC) allows the use of smaller, lower cost bulk capacitors, reduces power line loading and stress on the switching FETs, and results in a power supply that fully complies with IEC1000-2-3 specification. The ML4824 includes circuits for the implementation of a leading edge, average current, “boost” type power factor correction and a trailing edge, pulse width modulator (PWM).

FEATURES

■ Internally synchronized PFC and PWM in one IC

■ Low total harmonic distortion

■ Reduces ripple current in the storage capacitor between the PFC and PWM sections

■ Average current, continuous boost leading edge PFC

■ Fast transconductance error amp for voltage loop

■ High efficiency trailing edge PWM can be configured for current mode or voltage mode operation

■ Average line voltage compensation with brownout control

■ PFC overvoltage comparator eliminates output “runaway” due to load removal

■ Current fed gain modulator for improved noise immunity

■ Overvoltage protection, UVLO, and soft start