Automotive-grade TVS for 12V/24V system rail clamping
The 1.5KE120CAH is a 1500 W bidirectional Zener TVS diode from Taiwan Semiconductor, AEC-Q101 qualified for automotive applications. Its 102 V reverse standoff voltage and 114 V minimum breakdown voltage put it squarely on 72 V to 96 V nominal DC bus rails found in electric vehicle battery packs, industrial servo drives, and high-voltage telecom rectifiers.
Clamping voltage and pulse current — what the numbers decide
At the 9.5 A peak pulse current (10/1000 µs waveform), the maximum clamping voltage is 165 V. That is the ceiling the protected circuit sees — a downstream 200 V-rated MOSFET or 175 V DC-link capacitor has margin. The 102 V standoff means the diode stays off during normal bus ripple up to that level, so no leakage current penalty under steady-state operation. AEC-Q101 qualification adds the reliability screening — 1000-hour high-temperature reverse bias and temperature cycling — that automotive PPAP submissions require.
Through-hole DO-201 — board-fit and sourcing note
The DO-201AA / DO-27 axial package is a standard 0.052-inch diameter lead, 0.375-inch body length. The lead bend radius and hole diameter for the PCB footprint follow the JEDEC DO-201 outline — no custom tooling needed.