What the clamping and breakdown specs mean for your rail
The 1.5SMC6.8CA-M3/9AT is a bidirectional transient voltage suppressor — Vishay's own TransZorb® family — rated 5.8 V reverse standoff with a minimum breakdown of 6.45 V and a 10.5 V clamping ceiling at the 143 A peak-pulse current (10/1000 µs waveform). That 10.5 V clamp is the figure that matters most in practice: when a surge hits, the diode clamps the protected rail below 10.5 V and dissipates up to 1500 W peak, preventing the downstream IC from seeing the overvoltage spike. The CA suffix designates bidirectional polarity — the diode clamps both polarities, so it sits across a single-ended rail without needing two opposing unidirectional devices.
DO-214AB SMC footprint and assembly context
The part ships in the DO-214AB (SMCJ) package on Tape & Reel, rated for surface-mount pick-and-place. The wide operating junction temperature range of -65 °C to 150 °C covers the full industrial envelope — from unheated warehouse storage through to equipment mounted in thermally aggressive enclosures. Note the spec explicitly lists Power Line Protection as "No" — this is a general-purpose TVS for signal-line or secondary rail clamping, not a primary AC mains protection device.
The part carries an Active lifecycle status from Vishay General Semiconductor — Diodes Division, so it is in regular production and suitable for new designs without a last-time-buy countdown. Availability and lead time confirmed at RFQ.