Surge protection for 64 V rails
The 1.5KE75CA-E3/54: The reverse standoff voltage of 64.1 V means the part sits idle below that DC bias and only starts conducting when the surge pushes the line above the 71.3 V minimum breakdown threshold. When the transient hits, the clamping voltage is held to 104 V maximum at the 14.6 A peak pulse current (10/1000 µs waveform). That 104 V ceiling is the voltage the downstream silicon sees — if the protected device's abs-max rating is above 104 V with margin, the TVS keeps it inside the SOA.
Bidirectional clamping for AC or dual-polarity lines
This makes the 1.5KE75CA-/54 a natural fit for AC signal lines, data pairs that swing below ground, or dual-polarity DC rails where two unidirectional parts would otherwise be needed back-to-back. The junction temperature range spans -55°C to 175°C, so the clamping performance holds across industrial cabinet ambients and under-hood engine bay conditions. The 1500 W peak pulse rating is derated above 25°C per the datasheet curve — at 125°C the effective power drops to roughly 750 W, which still covers most IEC 61000-4-5 surge levels at the secondary side.
Through-hole mounting and package availability
The DO-201AA (DO-27) axial leaded package is a standard through-hole form factor. The leads are tin-plated copper; the body is molded epoxy with the cathode band marked — for a bidirectional part the band is absent or replaced by a bidirectional symbol.