DESCRIPTION
Typical applications cover off line power supplies for battery charger adapters, standby power supplies for TV or monitors, auxiliary supplies for motor control, etc. – Automatic burst mode in low load condition. – Overvoltage protection in hiccup mode. DRAIN ON/OFF REGULATOR 60kHz OSCILLATOR INTERNAL SUPPLY OVERTEMP. DETECTOR R1 S FF PWM LATCH Q R2 R3 R4 VDD 8/14.5V _ BLANKING + OVERVOLTAGE LATCH Q + _ 0.23 V + 42V _ S R FF 230 Ω 1 kΩ FB SOURCE September 2002 1/15 VIPer22ADIP / VIPer22AS PIN FUNCTION Name Function Power supply of the control circuits. Also provides a charging current during start up thanks to a high voltage current source connected to the drain. For this purpose, an hysteresis comparator monitors the VDD voltage and provides two thresholds: - VDDon: Voltage value (typically 14.5V) at which the device starts switching and turns off the start up current source. - VDDoff: Voltage value (typically 8V) at which the device stops switching and turns on the start up current source.