800 V breakdown, 10 W flyback — the scorch-mark tells you
The STMicroelectronics VIPER15HD is an offline flyback switching regulator from the VIPer™ plus family, integrating a 800 V avalanche-rugged power MOSFET and controller in a single 16-SOIC package. It delivers up to 10 W of isolated output power at a 225 kHz switching frequency, with built-in fault protection covering current limiting, over-temperature, and over-voltage conditions. The 800 V breakdown rating means this part handles universal AC input (85–265 VAC) with healthy margin, and the 225 kHz switching keeps the transformer small — useful when board space in a 10 W adapter or auxiliary supply is tight.
Junction temperature and supply range
The Vcc supply range of 8.5 V to 23.5 V and a 14 V start-up threshold are standard for offline flyback controllers. The output isolation is rated as isolated, confirming the transformer provides galvanic separation between primary and secondary — no optocoupler feedback is implied by this spec alone, but the flyback topology naturally supports it.
Obsolete — the replacement question
The VIPER15HD is listed as obsolete. If you are designing a new BOM, look at current VIPer™ plus family members in the same 16-SOIC footprint — the VIPer16HD or VIPer17HD share the same pinout and 800 V rating, though their protection feature sets differ. Confirm the exact pin compatibility against the datasheet before committing a replacement.