100 W flyback with integrated 700 V MOSFET — what the ratings mean
The STMicroelectronics VIPER100A-22-E is a monolithic offline flyback switching regulator from the VIPER™ series, integrating a 700 V avalanche-rugged power MOSFET and PWM controller in a single Pentawatt-5 HV package. It delivers up to 100 W in isolated flyback topologies, making it a fit for auxiliary and main switched-mode supplies in industrial, consumer, and telecom equipment where board space and component count are constrained. The 700 V breakdown voltage provides adequate headroom for universal AC input (85–265 VAC) flyback designs, though derating for line transients and leakage inductance spikes should be checked against the application's operating conditions. The 100 W power rating is the maximum output capability in a typical flyback configuration; actual deliverable power depends on the transformer design, ambient temperature, and thermal management of the Pentawatt-5 HV package.
Switching frequency, control, and protection — design-in checklist
The internal oscillator runs up to 200 kHz, enabling smaller transformer and output filter components compared to 65 kHz designs. The trade-off is increased switching losses in the integrated MOSFET, so the thermal budget at full load and high line must be validated with the package's junction-to-ambient thermal resistance. Control features include an enable pin, frequency control, and soft start. Fault protection covers current limiting and over-temperature shutdown. The supply voltage range is 8 V to 15 V (Vcc/Vdd) with an 11 V start-up threshold. These features simplify the bias supply design and protect against common offline fault conditions.
Buyers should evaluate pin-compatible alternatives in the VIPER™ family or a modern offline switcher with similar power and voltage ratings for new designs.