
Fairchild Semiconductor
GENERAL DESCRIPTION
The ML4803 is a space-saving controller for power factor corrected, switched mode power supplies that offers very low start-up and operating currents. Power Factor Correction (PFC) offers the use of smaller, lower cost bulk capacitors, reduces power line loading and stress on the switching FETs, and results in a power supply fully compliant to IEC1000-3-2 specifications. The ML4803 includes circuits for the implementation of a leading edge, average current “boost” type PFC and a trailing edge, PWM.
FEATURES
■Internally synchronized PFC and PWM in one 8-pin IC
■Patented one-pin voltage error amplifier with advanced input current shaping technique
■Peak or average current, continuous boost, leading edge PFC (Input Current Shaping Technology)
■High efficiency trailing-edge current mode PWM
■Low supply currents; start-up: 150µA typ., operating: 2mA typ.
■Synchronized leading and trailing edge modulation
■Reduces ripple current in the storage capacitor between the PFC and PWM sections
■Overvoltage, UVLO, and brownout protection
■PFC VCCOVP with PFC Soft Start