DESCRIPTION
Various functions such as over voltage detection, over current detection, soft start, feedback-loop disconnection detection, Power Good signal output, and holding function of PFC operation through momentary outage (PFC hold function) are incorporated in a single chip. The PFC function enables the continuation of PFC operation for a specified period when a momentary outage occurs, so that quick recovery after a sufficiently momentary outage is achieved*. The continuance time can be adjusted by an external capacitance. The PFC output voltage is monitored by checking the Power Good signal. When the power-factor correction is “good,” the Power Good signal is output after a delay time to secure stabilization of the PFC output voltage; when the power factor correction is not good, the output is stopped immediately. The delay time and power good stop level are adjustable by using an external circuit. PFC operation can be turned on and off by an external control signal. By using this function, PFC operation can be disabled at low input voltage, allowing remote control from the secondary side.
Renesas Electronics
