TVS clamp for a 20 V rail
The SMAJ20A-13-F is a unidirectional TVS Zener diode from Diodes Incorporated, rated for 400 W peak pulse power across a 10/1000 µs waveform. Its 20 V reverse standoff voltage sits just below the 22.2 V minimum breakdown, so it stays transparent on a nominal 20 V supply until a transient pushes the rail above that threshold.
Clamping voltage and current handling
When the transient exceeds breakdown, the diode clamps at 32.4 V maximum while conducting 12.3 A peak pulse current. That clamp voltage is the ceiling the downstream circuitry must survive — a 20 V-rated IC on the same rail sees the full clamp level during the event. The device operates across -55 °C to 150 °C junction temperature, covering the full industrial and automotive ambient range. The DO-214AC SMA package is a standard surface-mount footprint compatible with reflow soldering.