onsemi lists the P6SMB75CAT3G as Obsolete. The AEC-Q101 qualification means any replacement must also carry automotive-grade reliability screening if the application requires it. A non-automotive TVS in the same package and voltage class may be footprint-compatible but does not meet the same qualification level.
Clamp voltage and standoff — sizing the protection window
The 64.1 V reverse standoff is the maximum continuous DC voltage the TVS can block without conducting — a 48 V nominal bus with 20 % tolerance sits at 57.6 V, leaving 6.5 V margin below the standoff. The 103 V clamp at 5.8 A is the voltage the downstream components see during the surge; the protected rail's breakdown rating must exceed this clamp level to survive the event. Capacitance is 140 pF at 1 MHz — negligible for power bus protection but relevant if the TVS sits on a high-speed data line; 140 pF adds signal degradation above a few MHz.