The L4981A L4981B power factor corrector controller can achieve a power factor of up to 0.99. It also limits line current distortion to less than 5%. The chip is made using BCD 60II technology and has all the features of a power factor corrector (PFC) pre-regulator, including line and load regulation, average current mode PWM, high current bipolar and DMOS totem pole output, low start-up current (typ. 0.3 mA), undervoltage lockout with hysteresis and programmable turn-on threshold, overvoltage, overcurrent protection, precise 2% on-chip reference, and external soft start.