Automotive-grade transient suppressor for 33 V rails
The 1.5KE39AH is a 1500 W peak-pulse Zener TVS diode from Taiwan Semiconductor's 1.5KE series, designed to clamp transients on 33.3 V reverse-standoff rails. Its AEC-Q101 qualification places it in the automotive temperature band of -55°C to 175°C — suitable for under-hood ECU, battery management, and sensor supply protection where the ambient sees 125°C+ and the junction climbs from self-heating during a surge event.
The minimum breakdown voltage is 37.1 V, so the diode starts conducting before the protected rail reaches its abs-max rating — a 33.3 V nominal rail with a 36 V abs-max sees the TVS clamp the transient before the downstream ICs see overvoltage. This clamping figure sets the voltage that appears across the protected load during a surge; if the downstream components are rated for 60 V, the 53.9 V clamp leaves margin. The 1500 W peak pulse power is the product of the clamping voltage and the peak pulse current — at 53.9 V × 29 A, the rating is consistent. The unidirectional channel means this device protects a single polarity rail; reverse-bias protection requires a second device or a different part number. Power line protection is not supported — this is a signal- or low-power rail TVS, not a mains surge suppressor.
Supplied in tape and reel for automated insertion. The base product number 1.5KE39 identifies the voltage variant; the 'AH' suffix denotes the automotive grade and AEC-Q101 qualification.