The R2A20111 is a power-factor correction (PFC) controller IC. This IC adopts continuous conduction mode as PFC operation. Various functions such as constant power limit, overvoltage detection, overcurrent detection, soft start, feedback-loop disconnection detection, and holding function of PFC operation through momentary outage (PFC hold function) are incorporated in a single chip. These functions reduce external circuitry. The constant power limit function allows to eliminate a significant amount of coil noise which is generated due to overcurrent detection operation in case of conventional overload. The PFC hold function enables quick recovery by continuing PFC operation after momentary outage. The hold time can be adjusted by an external capacitance. Overcurrent detection pin is separately provided. Latch mode shutdown function is incorporated. A soft-start control pin provides for the easy adjustment of soft-start operation, and can be used to prevent overshooting of the output voltage.