500W Zener TVS in an Axial Lead – Protection Without the Guesswork
The 1N6122A is a 500W peak-pulse-power Zener TVS diode from Microchip Technology, designed to clamp transients on a 35.8V nominal rail before they reach the downstream silicon. Its 64.6V maximum clamping voltage at 7.7A peak pulse current (10/1000µs waveform) sets the upper bound on voltage stress that the protected circuit must survive — a key number for the board-level surge budget, not just a datasheet line. This is a unidirectional device in a through-hole axial package (B, Axial), suited for point-of-entry protection on DC power buses, industrial control inputs, and telecom line cards where a soldered lead gives mechanical standoff and thermal mass that surface-mount parts cannot match.
The 64.6V clamp at 7.7A peak pulse current means that any component on the protected rail must have a breakdown rating above that level, or the TVS becomes the last line of defence. The 35.8V reverse standoff is the maximum continuous DC voltage the diode can block without conducting — design the rail at 35V or below to keep leakage negligible under normal operation. The 44.7V minimum breakdown voltage gives a 25% margin above the standoff, which is tight enough to respond fast to an overvoltage event but wide enough to avoid nuisance triggering from supply ripple.
Active Production – Sourcing for the BOM Line
Microchip lists the 1N6122A as Active — no end-of-life notice, no last-time-buy clock. Quantity breaks and lead time are confirmed at quote time; the active status means the supply chain is open and multi-source across distributors.