Board-level transient protection for general-purpose rails
The SMBJ78CA-13-F is a bidirectional Zener-type TVS diode from Diodes Incorporated's SMBJ series, designed to clamp voltage spikes on general-purpose DC rails. The 78V reverse standoff voltage (VRWM) means the part conducts negligible leakage below that level — it sits across the rail without loading it. When a transient exceeds 86.7V (minimum breakdown), the Zener avalanche clamps the surge to 126V, shunting up to 4.7A peak pulse current to ground.
Package and board-fit for field replacement
The SMB body is large enough to hand-solder with tweezers and a fine tip, so a field swap on a populated board is practical without a reflow oven. The wide range also means the part survives soldering thermal shock without parametric shift.
Active lifecycle and sourcing posture
The base product number SMBJ78 covers both unidirectional and bidirectional variants — the CA suffix in SMBJ78CA-13-F specifically denotes the bidirectional channel.