800V avalanche-rated MOSFET — offline without a clamp
The VIPER16HD integrates an 800 V avalanche-rugged power MOSFET and a 115 kHz PWM controller in a single 16-SOIC package. That breakdown voltage lets it sit directly on rectified 230 VAC mains in a flyback or buck topology without needing an external clamping circuit — a straight BOM simplification for auxiliary supplies up to 10 W.
10 W continuous — where the thermal budget lands
The 10 W power rating is the continuous output ceiling in flyback configuration at 115 kHz. The 150°C junction rating means this part can deliver that 10 W inside a sealed industrial enclosure or an outdoor telecom box without forced air — the copper area on the SO-16 footprint is the derating lever. At lower ambient or with a heatsink pad, you can push toward the peak capability, but for a BOM commit, 10 W is the safe continuous number.
Topology flexibility — flyback, buck, buck-boost
The controller supports flyback, buck, and buck-boost topologies, with output isolation selectable as either. The 70 % duty cycle and 11.5 V to 23.5 V Vcc range cover the common auxiliary-rail voltages. Fault protection includes current limiting and over-temperature shutdown, and the 13 V start-up threshold ensures clean power-on from the bulk cap.
STMicroelectronics lists the VIPER16HD as active.