43V rail guard in a compact SMA package
It delivers 400W peak pulse power in the standard DO-214AC (SMA) surface-mount package, making it a common choice for protecting DC power inputs, relay coils, and industrial sensor lines where board space is tight.
Clamping voltage and the protection window
The protection window is defined by three voltages: reverse standoff at 43V (the rail voltage it leaves alone), minimum breakdown at 47.8V (where it starts conducting), and maximum clamping at 91V at the rated peak pulse current of 25A (8/20µs waveform). The 91V clamp is the voltage the downstream circuitry must survive — a 100V-rated MOSFET or capacitor on that rail has comfortable margin; a 60V-rated part does not. The 25A peak pulse current rating gives a direct check against the expected transient energy in the application.