Offline switcher for 1 W auxiliary supplies
The STMicroelectronics VIPER318XDTR is a monolithic offline switching regulator from the VIPER™ series, integrating an 800 V breakdown MOSFET and a PWM controller in a 16-SOIC package. It delivers up to 1 W in non-isolated topologies including buck, boost, buck-boost, and flyback. The 30 kHz fixed switching frequency keeps transformer size small for low-power auxiliary supplies, while the built-in soft start limits inrush at power-up.
Protection suite and operating range
Fault protection covers over load, over temperature, over voltage, and short circuit — the part shuts down cleanly rather than letting the winding saturate or the junction exceed 150°C. The Vcc supply range spans 4.5 V to 30 V, with an 8 V startup threshold that ensures reliable turn-on from a charged bulk cap.