20 W flyback with 800 V avalanche-rated MOSFET
The VIPER26HN integrates a 800 V avalanche-rated power MOSFET and a PWM controller in a single 7-lead DIP package, targeting off-line flyback supplies up to 20 W. The 115 kHz switching frequency lets you shrink the transformer core without pushing the MOSFET into excessive turn-off losses — a solid middle ground for auxiliary and bias supplies.
Start-up, supply range, and protection
Start-up happens at 13 V on the Vcc pin; the operating supply range spans 11.5 V to 23.5 V, giving you room to ride through bus ripple on the bias winding. On-chip fault protection includes cycle-by-cycle current limiting and thermal shutdown — the 150 °C junction rating means the thermal foldback kicks in before the silicon sees danger.
Flyback topology and duty-cycle headroom
Rated for flyback topology with output isolation configurable as either isolated or non-isolated. The 70 % maximum duty cycle gives enough headroom for universal AC input designs where the reflected voltage and leakage spike demand a wide on-time window.
STMicroelectronics lists the VIPER26HN as Active. The through-hole 7-DIP package keeps it compatible with legacy designs and hand-assembly lines. ROHS3 compliant.
Sourcing through distribution
The 7-DIP through-hole package is widely inventoried across the distribution channel — confirm the exact reel or tube quantity with your quote request.