Protection window for a 75 V rail
The SMAJ75CA-13: This means a 75 V bus sees no leakage at nominal voltage, the device starts conducting above 83.3 V, and the clamp holds the surge to 121 V — well within the typical 150 V–200 V rating of downstream DC-DC converters and downstream silicon. The 400 W rating is the industry-standard power class for DO-214AC (SMA) packaged TVS diodes — it handles the energy from a typical 75 V supply transient without exceeding the junction temperature limit of 150°C.
Bidirectional — one device covers both polarities
This is a single-channel bidirectional TVS. The back-to-back Zener structure clamps positive and negative transients symmetrically, so a single SMAJ75CA-13 protects a signal pair or an AC-coupled line without needing two unidirectional devices in anti-series. The bidirectional configuration also eliminates the risk of reverse-installation errors on the PCB.
Package and board-fit
Housed in the DO-214AC (SMA) package, with the supplier device package also designated SMA. This is a surface-mount package with a standard footprint shared across multiple manufacturers — the same 400 W TVS from Vishay, Littelfuse, and ON Semiconductor uses the identical land pattern. The junction temperature range spans -55°C to 150°C, covering industrial and automotive under-hood ambient conditions. Available in Tape & Reel (TR) and Cut Tape (CT) options. The Tape & Reel format is suited for automated pick-and-place assembly; Cut Tape supports prototype and low-volume builds without committing to a full reel.