What AEC-Q101 means for your automotive BOM
The 1.5KE33CH: That means it has passed the full suite of reliability screens: temperature cycling, high-temperature reverse bias, and ESD/latch-up immunity. The operating junction temperature range spans -55°C to 175°C, covering the under-hood and engine-bay thermal profile that industrial-grade parts cannot guarantee.
Clamping voltage and surge current — the real protection numbers
The peak pulse current is 33A. This means a 24V automotive bus (nominal) sees the diode remain non-conducting under normal conditions, then clamp a 33A surge to 47.7V — well within the typical 60V abs-max of downstream ECU components.
Axial-lead DO-201 package — board-fit for through-hole designs
The DO-201AA (DO-27) axial-lead package is a through-hole footprint that has been a standard for TVS diodes for decades. The 0.042-inch lead diameter fits standard 1.0 mm PCB holes. The body length is about 7.6 mm; the anode and cathode bands are clearly marked. Bidirectional operation means there is no polarity concern — the diode clamps equally in both directions, so the board orientation is non-critical.