Breakdown and clamping: the guardrails
The 1.5KE47CA B0G: Breakdown voltage is specified at 44.7 V minimum, so the device starts conducting before the rail crosses 45 V. The clamping ceiling of 64.8 V means a 48 V bus sees the spike held under 65 V—within the 80 V abs-max of many downstream DC-DC converters. The single bidirectional channel handles both positive and negative transients on the same line, eliminating the need for two unidirectional diodes in anti-series. That simplifies the BOM for a balanced signal pair or a floating supply rail. The DO-201AA axial-lead package (DO-27 equivalent) is through-hole, suited for high-reliability point-to-point wiring or PCB layouts where the lead bend absorbs thermal cycling stress.
Active production and sourcing posture
Taiwan Semiconductor lists the 1.5KE47CA B0G as Active.