VIPER27LN

VIPER27LN is a member of ST's VIPerPlus family of high-voltage offline flyback converters, integrating an 800 V avalanche-rugged power MOSFET with a fixed-frequency PWM controller in a through-hole DIP-7 tube package. The L version switches at 60 kHz (the H version is 115 kHz — do not cross the two when matching a design), holds standby consumption under 50 mW at 265 Vac, and covers the 12 W adapter and auxiliary-supply class for appliances, metering and industrial controls. Built-in frequency jitter softens EMI, while two-level overcurrent protection, overvoltage and overload protection, hysteretic thermal shutdown, soft-start and automatic fault restart reduce the external protection circuitry a flyback normally needs. Selection advice: confirm the transformer and compensation were designed around the 60 kHz L-type switching point before ordering this code against an H-type BOM line, and check the load's start-up behaviour against the soft-start and hiccup profile. Parameters verified against the ST datasheet and the ST product page.