It is a unidirectional transient voltage suppressor designed to clamp voltage spikes on 22V nominal rails, with a minimum breakdown voltage of 24.4V and a maximum clamping voltage of 48.3V at the rated peak pulse current of 48A (8/20µs waveform).
The 24.4V minimum breakdown voltage guarantees the avalanche triggers before the protected circuitry's absolute maximum rating is exceeded. The 48.3V clamping voltage at 48A peak pulse current defines the worst-case voltage the downstream components must survive during a surge event. The 400W peak pulse power rating (10/1000µs waveform) gives the energy-handling capability for repetitive transients in an automotive 12V or 24V electrical system.
The -55°C to 150°C operating junction temperature range covers under-hood and engine-bay environments, as well as cold-crank and hot-soak conditions.
The base product number is SM4T26, and the series includes other voltage variants in the SM4TY family for different rail protection levels.