3 kW automotive TVS in a DO-214AB SMC package
The SM30T7.5AY is a unidirectional Zener-based TVS diode from STMicroelectronics, part of the TRANSIL™ SM30TY series qualified to AEC-Q101 for automotive applications. It provides a peak pulse power rating of 3000 W (3 kW) for a 10/1000 µs waveform, clamping transients at 11.2 V maximum while conducting up to 268 A peak pulse current. The 6.5 V reverse standoff voltage protects 5 V and 3.3 V rails in automotive ECUs, ADAS sensors, and body-control modules where voltage spikes from load dump, alternator ripple, or inductive switching must be absorbed.
What AEC-Q101 grade means for your PPAP
AEC-Q101 qualification is the hard gate for any semiconductor in an automotive BOM. An industrial-grade TVS with the same standoff voltage would lack the high-temperature reverse-bias (HTRB) and power-temperature cycling (PTC) data that an auditor will ask for. If your design targets a production line, this part gives you the paperwork traceable to the wafer lot.
Clamping behavior and rail protection
The 6.5 V reverse standoff voltage (VRWM) means the SM30T7.5AY will not conduct leakage current on a 5 V supply rail under normal operation. Breakdown voltage starts at 7.13 V minimum, so the part remains out of the circuit until a transient pushes the rail above that threshold. The clamping voltage is specified at 11.2 V maximum when the full 268 A peak pulse current flows — that clamp margin protects downstream 5 V logic, CAN transceivers, or sensor ICs from exceeding their absolute maximum ratings during a 3 kW surge. Power line protection is not provided (the device is unidirectional), so it is intended for single-ended rail clamping, not AC or bidirectional bus protection.