What 1.5SMC7.5C delivers as a transient suppressor
Reverse standoff of 6.4 V nominal means the device idles off the circuit until a transient exceeds that threshold, then clamps without drawing continuous current — a key distinction from a Zener used for regulation, where conduction is intentional and continuous. With 1500 W peak pulse power and a junction temperature range to 150°C, the part handles the thermal headroom of short-duration industrial transients; the -55°C lower limit covers cold-start and outdoor equipment scenarios where supply rail overshoot is a first-event risk.
Why this part is now a sourcing decision, not a design decision
The 1.5SMC7.5C carries an obsolete product status — it is no longer recommended for new designs and Littelfuse has not published an official direct replacement order code in the ledger. For an active BOM line running this part, the path forward is either independent-distribution surplus stock (lot-traceable where available) or qualification of a pin-compatible alternative in the same DO-214AB SMCJ footprint. Because the 1.5SMC series is a standard SMCJ-form-factor family, any qualified 6.4 V standoff bidirectional TVS in the DO-214AB package is a candidate — the clamping voltage (11.87 V) and peak pulse current (134.5 A) are the gating specs for equivalence; verify both under the same 10/1000 µs test condition before committing to an alternate.