VIPER28HN

Overview

The VIPER28HN is an off-line high voltage converter from the VIPerPlus family, integrating an 800 V avalanche-rugged power MOSFET with a PWM current-mode controller. It operates at a fixed switching frequency of 115 kHz with jitter for EMI reduction. The device supports flyback topology and delivers up to 20 W output power with a maximum output current of 1.2 A. It features an adjustable Extra Power Timer (EPT) to sustain overload conditions, dual-level overcurrent protection, and automatic restart after faults. Operating input voltage ranges from 8.5 V to 23.5 V, with a no-load consumption of 30 mW at 230 Vac.

Feature Summary

• Integrates an 800 V rugged power MOSFET with embedded HV startup and sense FET
• Features an adjustable Extra Power Timer (EPT) to manage peak load currents for limited durations
• Includes comprehensive protections such as dual-level OCP, output overvoltage, short-circuit, and thermal shutdown

Applications

• Printers requiring temporary extra-power management
• Audio systems with intermittent peak load demands
• General purpose AC/DC converters for low power applications

Procurement Notes

Verify the specific suffix HN against official STMicroelectronics documentation to confirm pinout and package configuration. Ensure compatibility with DIP-7 through-hole mounting requirements. Cross-reference the datasheet for any recent product change notices regarding metal mask modifications or environmental compliance updates before finalizing procurement.

Selection Notes

Select this component when designing flyback converters requiring high voltage ruggedness and peak power capability. The 115 kHz frequency suits applications needing moderate size magnetics. Consider the EPT function if the application experiences short-duration load spikes exceeding continuous ratings. Verify that the 800 V breakdown voltage aligns with the maximum DC bus voltage in the target design.

Part Context

The VIPER28HN belongs to the VIPerPlus series of integrated switchers. This family combines high-voltage power MOSFETs with intelligent control logic to simplify offline power supply designs. The HN suffix denotes the 115 kHz operating frequency variant, distinct from the L type which operates at 60 kHz. It is part of STMicroelectronics' portfolio for energy-efficient power management ICs.

Replacement Considerations

Official substitutes within the same family include the VIPER28L for 60 kHz operation. Check for direct pin-compatible alternatives only if the switching frequency difference is acceptable for the magnetic components.