Offline switcher for compact 1 W rails
The VIPER319HDTR from STMicroelectronics is a monolithic offline switching regulator that integrates an 800 V avalanche-rugged power MOSFET and a PWM controller. It delivers up to 1 W of output power across flyback, buck, boost, and buck-boost topologies — a single BOM line for non-isolated or isolated auxiliary supplies in appliances, metering, and industrial control.
Switching frequency and protection set
Fixed 132 kHz switching frequency lets you size the transformer or inductor for a compact footprint while keeping switching losses manageable at the 1 W power level. The part includes cycle-by-cycle current limiting, over-voltage, over-temperature, and short-circuit protection — it shuts down before the winding saturates or the junction exceeds 150°C. Start-up voltage is 8 V, and the supply range (Vcc) spans 4.5 V to 30 V, giving headroom for auxiliary winding regulation. Soft-start is built in, so the output ramps without overshoot into a capacitive load.