What this 1.5 kW TVS actually clamps
The 1.5KE43-E3/73: The 1.5KE43-/73 is a 1500 W peak-pulse Zener-type TVS from Vishay's TransZorb® series, designed to clamp transients on general-purpose DC rails. Its 34.8 V reverse standoff means it sits across a 24 V or 28 V bus without conducting in normal operation, and the 38.7 V minimum breakdown voltage ensures the avalanche triggers before the downstream silicon sees damage. When the transient hits, the diode clamps at 61.9 V maximum while shunting 24.2 A of peak pulse current (10/1000 µs waveform). That 1.5 kW rating is the product of clamp voltage and peak current — a standard TVS sizing metric for a single 1 ms surge event at 25 °C.
DO-201AA axial package and board fit
Housed in a DO-201AA (DO-27) axial-lead package, this part is a through-hole device intended for point-to-point wiring or PCB mounting with 0.100-inch pitch holes. The 1.5KE supplier device package code matches the standard JEDEC outline — no footprint surprises if you have placed a 1.5KE-series part before.
Obsolete — sourcing reality for the 1.5KE43-E3/73
Vishay lists the 1.5KE43-/73 as obsolete.