20 W isolated flyback with 800 V avalanche-rugged MOSFET
The VIPER37HD integrates a 800 V avalanche-rugged power MOSFET and a PWM controller in a single 16-SO package, delivering up to 20 W in an isolated flyback topology. The fixed 115 kHz switching frequency simplifies transformer design and EMI filter component selection. Start-up voltage is 14 V, with a Vcc operating range of 8.5 V to 23.5 V, giving headroom for universal AC input designs. The 80% maximum duty cycle supports wide input-voltage variations without pulse-skipping.
Fault protection and thermal rating
Built-in fault protections cover current limiting, over-temperature, and over-voltage — the over-temperature shutdown uses a junction-temperature sense, not a board-level thermistor.
STMicroelectronics lists VIPER37HD as Active product status. The base number VIPER37 covers multiple variants; the HD suffix denotes the 16-SO package. ROHS3 compliant. Sourced per RFQ — confirm the BOM quantity and target delivery window. The package is supplied in tube; reel quantities may require a different suffix.
16-SO narrow body (0.154" width, 3.90 mm body width) — a standard SOIC footprint. Surface-mount only.