Flyback switcher with integrated 800V MOSFET
The VIPER38HDTR is an offline flyback switcher from STMicroelectronics' VIPer™ plus series, integrating the power MOSFET and controller in a single 16-SOIC package. It delivers up to 20 W of isolated output power from a universal AC input. The 800 V breakdown rating on the integrated MOSFET provides substantial margin for universal AC line input (85–265 VAC) flyback designs, where reflected voltage and leakage inductance spikes can stress the switch beyond the nominal rail. Switching at a fixed 115 kHz, the transformer core size is smaller than a 65 kHz design, but the EMI filter must be designed for the fundamental and its harmonics. The fixed frequency simplifies filter tuning versus a quasi-resonant or variable-frequency controller.
Protection set reduces external BOM
On-chip fault protection covers current limiting, over-temperature, over-voltage, and short-circuit conditions. This built-in set eliminates the need for external sense resistors or optocoupler-based protection in many designs, shrinking the BOM count. The start-up voltage is 14 V, and the supply range (Vcc) spans 8.5 V to 23.5 V, accommodating a wide auxiliary winding output without an external LDO.
Active production in 16-SOIC package
It is supplied in tape and reel (TR) and cut tape (CT) options for the 16-SOIC (0.154-inch width) package, suitable for reflow assembly. ROHS3 compliant and lead-free per the L* entry, the part meets current environmental directives for commercial and industrial equipment.