L6563/L6563A are ST's advanced transition-mode PFC controllers, featuring very precise adjustable output overvoltage protection, tracking boost function, protection against feedback loop failure (Latched shutdown), interface for cascaded converter's PWM controller, input voltage feedforward (1/V2), inductor saturation detection (L6563 only), remote ON/OFF control, low (≤ 90µA) start-up current, 5mA max. quiescent current, 1.5% (@ TJ = 25°C) internal reference voltage, -600/+800 mA totem pole gate driver with active pull-down during UVLO.