Last-buy status — what it means for your BOM
The 1.5KE47A-E3/51: Vishay has flagged the 1.5KE47A-/51 as Last Buy — the manufacturer is winding down production, and this is the final procurement window before it goes EOL. For a repair bench or a legacy BOM that depends on this TransZorb part number, the scorch-mark tells you the TVS did its job; the question is whether you have enough stock to cover the remaining service life of the product.
Clamping voltage and power — the numbers that matter
The reverse standoff voltage is 40.2 V, meaning the diode stays out of the circuit below that rail; breakdown starts at 44.7 V min, and clamping is guaranteed at 64.8 V max when the 23.1 A peak pulse current flows. Unidirectional — one channel, so it protects a single DC rail against positive transients above the breakdown voltage.
Through-hole DO-201AA — board-fit note
Axial-lead DO-201AA (also known as DO-27) package — the body is 9.1 mm long, the leads are 1.3 mm diameter tinned copper, and it mounts through a 1.1 mm hole in the PCB.