400W bidirectional TVS in a DO-214AC package — what it covers and what it doesn't
Its 400W peak pulse power rating (10/1000µs waveform) and 25.3V clamping voltage at 91A (8/20µs) mean it handles moderate surges on low-voltage DC buses — think 12V automotive accessory lines, industrial sensor supplies, or telecom card rails. The DO-214AC (SMA) footprint is a common surface-mount package, so board layout is straightforward. Note the 13.3V minimum breakdown voltage: the diode starts conducting just above the 12V standoff, so the protected rail must tolerate that threshold without false triggering.
Clamping voltage and peak current — the real protection numbers
The 25.3V clamping voltage at 91A (8/20µs) is the number that matters when sizing downstream components: any IC on the protected rail must survive that peak voltage for the surge duration. The 400W rating is the 10/1000µs waveform, a longer pulse than the 8/20µs used for the current spec — so for fast transients (ESD, lightning-coupled spikes) the 91A figure is the relevant limit. Power line protection is marked as 'No', meaning this is a signal- or low-power-rail protector, not a mains-side suppressor.