AU1FK-M3/I

Overview

The AU1FK-M3/I is a single ultrafast recovery rectifier manufactured by Vishay General Semiconductor. It features an 800 V maximum repetitive reverse voltage and supports a continuous forward current of 1 A. The device utilizes avalanche-rated technology, allowing it to withstand unclamped inductive switching events. Key electrical parameters include a maximum forward voltage of 1.85 V at 1 A, a peak non-repetitive surge current rating of 25 A, and a typical reverse leakage current of 1 µA. The component exhibits a fast reverse recovery time of 75 ns. It operates within a junction temperature range of -55 °C to +175 °C and is housed in the DO-219AB (SMF) surface-mount package.

Feature Summary

• Avalanche-rated capability for robustness against inductive load switching transients
• Ultrafast recovery characteristics with minimal stored charge for high-frequency efficiency
• High thermal stability supporting operation up to 175 °C junction temperature

Applications

• High-frequency DC-DC converter output rectification
• Inductive load freewheeling diodes in motor control circuits
• Unclamped inductive switching protection in power supplies

Procurement Notes

Verify the specific suffix configuration upon ordering, as variations such as /H or /I may denote differences in tape-and-reel specifications or packaging standards rather than electrical performance. Confirm that the required quantity aligns with the manufacturer's standard factory pack sizes to avoid partial reel handling fees. Ensure the procurement channel provides traceability documentation consistent with Vishay's quality management systems for critical applications.

Selection Notes

Select this component when circuit design requires an 800 V blocking voltage combined with avalanche ruggedness. The 1 A current rating suits low-to-medium power conversion stages. Engineers should evaluate the 75 ns reverse recovery time against switching frequency requirements to minimize conduction losses. The SMF package offers a compact footprint suitable for space-constrained printed circuit board layouts compared to through-hole alternatives.

Part Context

This part belongs to Vishay's AU1 series of ultrafast recovery rectifiers designed for surface-mount assembly. The AU1FK variant specifically targets applications demanding higher voltage ratings than the 600 V variants while maintaining fast switching speeds. The M3 designation indicates lead-free construction compliant with RoHS directives. This series complements Vishay's broader portfolio of high-voltage discrete semiconductors for industrial and consumer power electronics.

Replacement Considerations

Direct pin-compatible substitutes within the same family include the AU1FM-M3/I (1000 V rating) or AU1FJ-M3/I (600 V rating), provided the voltage margin allows adjustment. Cross-brand replacements must match the 800 V reverse voltage, 1 A forward current, and DO-219AB package outline. Verify that any alternative device also meets the avalanche energy requirements if used in inductive switching environments.