100 W flyback with a 620 V internal MOSFET
The STMicroelectronics VIPER100-22-E is an offline flyback switching regulator that integrates the PWM controller and a 620 V avalanche-rugged power MOSFET in a single Pentawatt-5 HV package.
Switching frequency and control flexibility
The internal oscillator runs up to 200 kHz. Control features include an enable pin, frequency control, and soft start. The Vcc supply range of 8 V to 15 V and a startup voltage of 11 V are typical for an offline self-biased converter; the undervoltage lockout thresholds are set to keep the MOSFET off until the bulk capacitor charges past the startup threshold.
Protection set and the Pentawatt-5 HV footprint
On-chip fault protection covers current limiting and over-temperature shutdown — the part latches off and recovers when the junction cools, which keeps the board from smoking through a shorted output diode or a fan failure. The Pentawatt-5 HV package uses bent and staggered leads that sit the body above the board — the exposed metal tab on top is the drain connection and the primary thermal path. A heatsink clips onto the tab or the tab is soldered to a copper island on the PCB; without that thermal management the 100 W ceiling is unreachable in still air.
STMicroelectronics lists the VIPER100-22-E as obsolete.