Transient protection for 28V rails
The 1N6156A is a Zener TVS diode from Microchip Technology designed to clamp transients on a nominal 28V DC rail. Its 29.7V reverse standoff voltage means the protected line can run at 28V without leakage, while the 53.6V clamping voltage at 28A peak pulse current limits the spike the downstream circuitry sees. The 1500W peak pulse power rating — specified with a 10/1000µs waveform — gives the energy-handling margin for industrial surge environments like motor drives or fieldbus power feeds.
Sizing the protection budget
For a 24V or 28V supply, the 29.7V standoff gives headroom above the nominal rail without triggering the TVS during normal ripple. The 53.6V clamp is the voltage the protected IC must survive — check the absolute-maximum rating of the downstream regulator or transceiver against this value. The 28A peak pulse current at 10/1000µs is the worst-case surge the diode can shunt; if the source impedance is low enough to push more current, a series resistor or a higher-power TVS is needed.
Active production — no LTB pressure
The through-hole axial package is a mature form factor — board-level inventory and hand-assembly are straightforward.