Bidirectional clamping in a through-hole axial footprint
The 1.5KE9.1CA-E3/73: A single bidirectional channel means the same device protects against positive and negative transients on AC lines or symmetrical signal pairs, reducing component count compared to back-to-back unidirectional TVS diodes. The DO-201AA axial package is a through-hole form factor suited for point-to-point wiring or PCB mounting where the lead bend absorbs thermal cycling stress — common in power supplies, telecom line cards, and industrial control boards that see repeated surge events.