What the 1500W peak pulse rating means on the line
The 1.5KE30AHE3_A/D is a 1500W (1.5kW) TransZorb TVS diode from Vishay's automotive-grade series, qualified to AEC-Q101. The 1500W rating at 10/1000µs waveform means it clamps a 36.2A peak pulse current to 41.4V max — enough to absorb the energy from a load-dump transient or an inductive kickback on a 24V truck bus without the part self-destructing. The 25.6V reverse standoff voltage sits comfortably below the nominal 24V rail, so the diode stays off during normal operation. At 28.5V min breakdown it starts conducting, and at 41.4V clamping it holds the downstream silicon safe. That 15V clamp-to-standoff margin is the energy absorption zone — the wider it is, the more pulse energy the diode can sink before the voltage rises to the damage threshold of the protected IC.
DO-201AA axial package and board integration
Through-hole DO-201AA (DO-27) axial package — the body is 9.1mm long, 5.3mm diameter, with tinned copper leads that solder into 1.0mm PCB holes. The axial form factor is common in automotive junction boxes and industrial power supplies where the diode is hand-inserted or wave-soldered. The lead bend radius must stay above 2.0mm to avoid cracking the glass passivation at the body-lead interface. At 1500W peak, the junction rises roughly 100°C above ambient in a 10/1000µs pulse, so 175°C gives margin for a 85°C under-hood soak plus a full-rail transient.
Automotive AEC-Q101 and production status
The TransZorb series is Vishay's branded TVS line with a reputation for tight breakdown tolerance and low leakage at high temperature.