500W bidirectional Zener TVS in SQ-MELF
The 1N6112AUS is a Zener-type transient voltage suppressor from Microchip Technology, rated for 500W peak pulse power per the 10/1000 µs waveform. It clamps transients at 25.1V maximum while conducting 19.9A peak pulse current, and its single bidirectional channel protects both polarities from a single device — a BOM-simplifying feature for symmetrical rail protection. The reverse standoff voltage is 13.7V typical, with a minimum breakdown of 17.1V. That puts it on a 12V nominal rail, with enough margin to avoid nuisance triggering from normal ripple while clamping hard on surges. Housed in an SQ-MELF (B) package, it is a surface-mount device with a cylindrical body — the same footprint used in MIL-spec and hi-rel designs. The package is rated for the full -55°C to 175°C junction temperature range, so it holds up in avionics, downhole, and outdoor telecom enclosures where the ambient can spike.
Active production — no obsolescence pressure
Microchip lists the 1N6112AUS as Active. The base product number is 1N6112, so if you need a different voltage variant in the same family, the datasheet covers the full range. The package is, not tape-and-reel, which is typical for hi-rel and small-quantity orders. If your line runs pick-and-place, confirm the feed method with your distributor at quote time.
Sourcing and fit for the BOM
The SQ-MELF package is a standard footprint, so layout changes are minimal if you are replacing a through-hole or different SMT TVS. The 500W peak pulse power is a common rating — check that your surge requirement does not exceed the 19.9A peak pulse current at the clamping voltage. If you need a different standoff voltage, that family is the natural cross-shop.