Clamping voltage and peak pulse power
The 1.5SMC6.8A-E3/57T: The 10.5V maximum clamping voltage at 143A peak pulse (10/1000 µs) is the figure that defines whether this part protects a given rail — the standoff of 5.8V sets the normal operating window, and when a transient exceeds the 6.45V breakdown minimum the clamp limits the spike to 10.5V before the 143A peak current flows through the device. 1500W peak pulse capacity means the device survives a single-event transient without degradation — the 10/1000 µs wave shape is the standard IEC 61000-4-5 surge waveform, so the 1.5SMC series is the go-to family for board-level protection on 5V and 12V rails.
Package and thermal margin
DO-214AB (SMCJ) is the footprint — the wide metal tab under the body is the primary thermal path to the PCB pad; adequate solder coverage and a thermally-rated pad keep the junction below the 150°C maximum under repetitive surge duty. Available in tape-and-reel and cut-tape — the TR option feeds high-volume pick-and-place; CT suits low-MOQ prototyping runs. The base product number 1.5SMC6.8 covers the 6.8V nominal Zener voltage across the series, so alternative parts in the same family with different standoff ratings share the same footprint.
Active sourcing posture
For a Vishay standard-line TVS in SMC, multi-source availability is typical through authorized channels, and independent distribution carries the same base part number for second-source hedging.