What the clamping stack means for circuit protection
The 1.5SMC6.8A-E3/9AT: The standoff voltage of 5.8 V sets the working rail — the TVS sits off-state below this without conduction. The breakdown minimum of 6.45 V is where the device first enters avalanche and begins clamping. Those three numbers — standoff, breakdown, clamping — are the selection chain: you size the standoff above your rail, the breakdown below the load's abs-max, and the clamping ceiling below what the protected device tolerates.
TransZorb heritage and the 1.5SMC thermal envelope
Vishay's TransZorb® series is a long-run TVS family — the DO-214AB SMC package carries 1500 W at the 10/1000 µs wave shape, which is the standard unidirectional clamping wave for mains-adjacent and supply-line protection. Junction temperature rating is -65 to +150 °C, giving the part headroom in enclosed equipment without active cooling — the thermal derate curve in the Vishay datasheet governs the allowable pulse repetition rate and duty cycle.
SMC package — Tape & Reel assembly fit
Surface-mount DO-214AB (SMCJ) lands are industry-standard across TVS families, so layout reuse from an alternate supplier is straightforward when second-source is desired. The Tape & Reel quantity confirms automated assembly flow — confirm reel diameter and leader length against your pick-and-place feeder spec before programming the placement head.