Zener TVS, 110 V Standoff, 500 W — DO-214AC
The SMAJ110AE3/TR13 is a Microchip Zener TVS diode designed to clamp transients on 110 V nominal rails. It offers a reverse standoff voltage of 110 V, a minimum breakdown voltage of 122 V, and a maximum clamping voltage of 177 V at the peak pulse current of 2.8 A (10/1000 µs waveform). The 500 W peak pulse power rating gives a reasonable margin for industrial and telecom surge events in a DO-214AC (SMA) surface-mount package.
Breakdown and Clamping — Guard Band for 110 V Rails
The 122 V minimum breakdown ensures the diode does not conduct at the 110 V standoff, leaving a 12 V guard band. The 177 V clamping ceiling limits the voltage seen by the protected circuit during a surge. The 2.8 A peak pulse current at the 10/1000 µs waveform is the current that flows through the diode at the clamping voltage — the actual surge current the diode can handle depends on the pulse duration and ambient temperature.
Microchip lists the SMAJ110AE3/TR13 as Active. The DO-214AC (SMA) package is widely used and second-sourced across the TVS industry, so board-level footprint compatibility is straightforward.
Single Unidirectional Channel — Polarity Matters
This is a unidirectional Zener TVS with one channel. For AC lines or bidirectional protection, a different part (e.g., SMAJ110CA) would be needed.