TVS clamping for a 6.5 V rail
The SMAJ6.5CA-13: This is a general-purpose protection part in the SMAJ family — the 400 W rating is the device's ability to absorb a single surge event without failing, not a continuous power dissipation figure.
Voltage thresholds and what they mean on the board
Above that, the breakdown voltage (7.22 V min) defines where the diode starts to avalanche. The 35.7 A peak pulse current rating (Ipp) at the 10/1000 µs waveform tells you the surge the part can handle before the junction overheats. For a shorter pulse (8/20 µs, common in ESD testing), the peak current capability is higher — the 400 W rating is the energy envelope.
Operating temperature range spans -55°C to 150°C junction, so it handles under-hood automotive ambient or industrial cabinet heat without derating the pulse power at the high end.