The TK83854 family of integrated circuits provide active power factor correction for power systems that otherwise would draw non-sinusoidal current from sinusoidal power lines. These parts implement all the control functions necessary to build a power supply preregulator capable of optimally using available power-line current while minimizing line-current distortion. To do this, the TK83854 contains a voltage amplifier, a precision analog multiplier/ divider, a current amplifier, and a fixed-frequency PWM. In addition, the TK83854 contains a power MOSFET gate driver, 7.5 V reference, line anticipator, load-enable comparator, low supply detector, and overcurrent comparator.