The 1.5SMC400 is listed as Obsolete by Littelfuse Inc.
Zener TVS parametrics and clamp performance
The clamping voltage at peak pulse current is 575.4V max, limiting the transient seen by the protected circuit. This power rating is the key selection parameter — it determines the maximum transient energy the diode can absorb without failure.
Delivered on Tape & Reel (TR), consistent with automated pick-and-place assembly.
