Automotive-grade transient suppressor for 17.1 V rails
The Vishay 1.5KE20CAHE3_A/D is a bidirectional TransZorb® TVS diode from the Automotive, AEC-Q101 qualified series, designed to clamp transients on 17.1 V nominal rails.
What the clamping and breakdown ratings mean for the BOM
The 17.1 V reverse standoff voltage (working voltage) means the diode draws negligible leakage below that rail — the protected circuit sees no added load during normal operation. The 19 V minimum breakdown voltage guarantees the avalanche triggers before the rail rises above the downstream component's abs-max rating. A 27.7 V maximum clamp at 54.2 A peak pulse current sets the voltage the protected device must survive during the transient. For a 24 V nominal automotive bus, this clamp stays below the typical 36 V abs-max of most ECUs and sensors, giving margin without needing a second-stage clamp. The single bidirectional channel replaces two unidirectional diodes in antiparallel — saves board space and assembly cost on a 17.1 V signal pair where the transient polarity is unknown.
Package and board-fit for the DO-201AA axial lead
The lead spacing and body diameter match the standard DO-201 footprint. Bend the leads 90° for horizontal board mounting or stand the body vertical; the thermal path to the board is through the leads, so keep the solder fillet full and the trace width adequate for the 54.2 A peak current.
Lifecycle and supply posture
The base product number 1.5KE20 covers a family of voltage variants in the same DO-201 package; the CAHE3 suffix specifically denotes the bidirectional, AEC-Q101 qualified version with the automotive-grade process and test flow.