Transient protection parameters for the 1.5KE20A-E3/51
At the 17.1 V reverse standoff voltage (the DC rail it protects), leakage current is negligible; when a transient exceeds the 19 V minimum breakdown threshold, the device clamps the surge to 27.7 V maximum while conducting 54.2 A of peak pulse current. This clamping voltage is the maximum the downstream circuitry sees — if the protected rail's absolute-max rating sits below 27.7 V, this part does not provide enough margin.
Last Buy lifecycle — procurement timeline
Vishay lists the 1.5KE20A-/51 as Last Buy. This means the manufacturer has announced end-of-life and is accepting final orders within a defined last-time-buy window. Once that window closes, the part will no longer be produced. For existing BOM lines, the procurement decision is time-sensitive: order the lifetime buy quantity now, or plan a qualification of a replacement part before the LTB expires.
The DO-201AA/DO-27 axial package (through-hole) suits leaded board layouts where the TVS is hand-soldered or wave-soldered into a plated through-hole — the axial leads handle the thermal stress of the soldering process without cracking the die attach.
Sourcing this part through independent distribution
RoHS compliance documentation is available from Vishay upon request.