Automotive-grade 1500 W transient suppressor for 24 V bus protection
The STMicroelectronics SM15T24AY is a unidirectional Zener TVS diode in the DO-214AB (SMC) package, rated for 1500 W peak pulse power (10/1000 µs waveform) and qualified to AEC-Q101. It is designed to clamp transients on 24 V automotive power buses and similar DC rails, with a 20.5 V reverse standoff voltage and a maximum clamping voltage of 42.8 V at the peak pulse current of 234 A (8/20 µs waveform).
The 42.8 V maximum clamping voltage is the voltage the protected circuitry must survive during a transient event. At 234 A peak pulse current (8/20 µs), this part handles the high-energy surges typical of load-dump and jump-start conditions on a 24 V nominal system. The 20.5 V standoff voltage means the diode will not conduct appreciably below that level, so it sits quietly across the rail during normal operation.
AEC-Q101 qualification — what the grade means for procurement
AEC-Q101 is the stress-test qualification standard for discrete semiconductors used in automotive electronics. It covers temperature cycling, high-temperature reverse bias, and surge robustness beyond commercial-grade parts. For a procurement buyer, the AEC-Q101 stamp means this part meets the PPAP documentation requirements an OEM auditor expects for under-hood or chassis-domain applications.
Package and footprint notes
The DO-214AB (SMC) package is a surface-mount footprint common for 1500 W TVS diodes. It is larger than the DO-214AA (SMA) or DO-214AC (SMB) packages, sized to handle the thermal dissipation of the 1500 W surge rating.