This demonstration board based on VIPER16 is designed as an example of a simple non-isolated auxiliary power supply for a range of input voltages from 85 VAC to 500 VAC. There is an ever-increasing demand for small power supplies capable of working without voltage range limitations, even at nominal levels of 400 VAC and 415 VAC, respectively. The real voltage level can reach 500 VAC (415 V + 20%). The major markets for this type of SMPS are home appliances and metering. The VIPER16 device includes an 800 V rugged power switch, a PWM controller, programmable overcurrent, overvoltage, overload, a hysteretic thermal protection, soft-start and safe auto-restart after any fault condition removal. Burst mode operation at light load combined with the very low consumption of the device helps to meet standby energy-saving regulations.