Automotive-grade transient suppressor for 26V rails
The STMicroelectronics SM30T30CAY is a bidirectional Zener TVS diode from the TRANSIL™ family, qualified to AEC-Q101 for automotive applications. It protects a single 26V nominal rail against transients up to 3kW peak pulse power (10/1000µs waveform), clamping at 42.1V maximum while conducting 71.3A peak pulse current. The DO-214AB (SMC) surface-mount package suits automated assembly lines common in automotive ECU production.
What the 3kW rating means for your protection budget
The 3000W peak pulse power rating at 10/1000µs defines the device's ability to absorb a single high-energy surge without failing. For a 26V rail, this translates to a clamping voltage of 42.1V at the rated current — the downstream circuitry must survive that peak. The 71.3A peak pulse current figure gives the surge-handling capacity in amperes, which is the parameter most directly comparable to the threat waveform in standards like ISO 7637-2 or ISO 16750-2 for automotive load dump and jump start.
Temperature range and automotive deployment
The 175°C upper limit accommodates hot spots near exhaust manifolds or turbochargers, while the -55°C floor handles cold-crank and arctic storage conditions.
Lifecycle and sourcing posture
For production BOMs requiring dual sourcing, the base product number SM30T30 covers the family — the CAY suffix denotes the bidirectional, AEC-Q101 qualified variant in the SMC package.