6.5V rail clamp — 7.22V breakdown threshold
The SMBJ6.5E3/TR13 is a unidirectional Zener TVS diode from Microchip Technology, designed to protect a 6.5V DC rail from transients. Its minimum breakdown voltage of 7.22V means it stays off during normal operation but starts conducting when the rail rises above that threshold — a 0.72V guard band above the 6.5V standoff. When a surge hits, the diode clamps at 12.3V maximum while shunting 48.7A of peak pulse current (10/1000µs waveform).
