GENERAL DESCRIPTION

The ML4801 is a controller for power factor corrected, switched mode power supplies. Key features of this combined PFC and PWM controller are low start-up and operating currents. 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 specifications. The ML4801 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 start-up current (200µA typ.)

■ Low operating current (5.5mA typ.)

■ Low total harmonic distortion

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

■ Average current continuous boost leading edge PFC

■ High efficiency trailing edge PWM optimized for current mode operation

■ Current fed gain modulator for improved noise immunity

■ Brown-out control, overvoltage protection, UVLO, and soft start