1500 W bidirectional TVS — protection window and lifecycle read
The 1.5KE9.1C-B: Bidirectional clamping means it protects symmetrical signal lines — AC power or bipolar data buses — where the transient can swing positive or negative relative to ground. The protection window is defined by a 7.78 V reverse standoff (the maximum DC voltage the line can carry without the diode conducting), an 8.17 V minimum breakdown voltage (where clamping starts), and a 14.07 V maximum clamping voltage at the 113.4 A peak pulse current. This translates to a clamp factor of roughly 1.8× the standoff — tight enough to protect downstream 12 V-rated silicon from transients. The DO-201AA (DO-27) axial-lead package suits through-hole board mounting where the lead bends absorb mechanical stress during wave solder.
Sourcing an obsolete TVS — where the 1.5KE9.1C-B sits in the cycle
The 1.5KE series is a long-running TVS family with many voltage variants still active, but the bidirectional 9.1 V version (C suffix) is discontinued. A parametric replacement would need to match the 1500 W peak pulse rating, the 7.78 V standoff, and the bidirectional configuration in the same DO-201 package — a board-level spin is not required if the replacement is pin-compatible, but no direct cross-reference is documented here.