Obsolete — surplus-channel sourcing
The 1.5SMC300C is listed as Obsolete by Littelfuse.
Clamping profile and application fit
The reverse standoff voltage is 256V, meaning the protected rail can sit at 256V DC without the device conducting. For a 256V DC bus — common in three-phase rectified industrial supplies — the 434.7V clamp keeps transients below the typical 600V MOSFET rating.
Package and temperature grade
The single bidirectional channel replaces two unidirectional devices in back-to-back configuration, saving board area.