Flyback regulator for off-line supplies — 20 W ceiling
The STMicroelectronics VIPER20-E is a monolithic flyback switching regulator integrating the PWM controller and a 620 V power MOSFET in a single Pentawatt-5 HV package. It delivers up to 20 W of isolated output power, targeting auxiliary power supplies in appliances, industrial controls, and AC-DC converters where board space is tight.
620 V breakdown and 200 kHz switching
The 620 V breakdown voltage gives enough headroom for universal AC input (85–265 VAC) rectified to a DC bus that peaks near 375 V. The switching frequency runs up to 200 kHz, which shrinks the transformer and output filter but pushes the EMI filter design — expect to budget for a common-mode choke and Y-capacitors at the input. Built-in current limiting and over-temperature protection reduce the external component count. The 8 V to 15 V supply range on Vcc/Vdd lets the auxiliary winding self-bias once the converter starts, with an 11 V startup threshold.
Pentawatt-5 HV — surface mount with staggered leads
The Pentawatt-5 HV package has bent and staggered leads, giving a surface-mount footprint while keeping the thermal and creepage characteristics of a through-hole power package.