Clamping protection for 28 V automotive rails
The SMCJ28CAQ-13-F: It clamps a surge on a 28 V DC rail — the reverse standoff voltage is 28 V, so at nominal 24 V or 28 V bus voltage the diode sits below the leakage threshold. When the transient exceeds 31.1 V (minimum breakdown), the device conducts and limits the voltage to 45.4 V maximum across the protected circuit. The DO-214AB (SMC) package footprint matches standard reflow profiles and is rated for surface-mount assembly.
The 33 A peak pulse current is the maximum current the TVS can shunt at the 10/1000 µs waveform without exceeding its 1500 W power rating. The 45.4 V clamping voltage is the maximum voltage the protected load sees during that surge — a downstream IC rated for 50 V or higher has margin; one rated for 40 V may need a lower-voltage TVS or additional protection. Because the device is bidirectional, a single SMCJ28CAQ-13-F protects both positive and negative transients on a signal or power line — no polarity orientation needed on the PCB. The "Power Line Protection" field is marked "No", which means this TVS is intended for DC power or signal rails, not for continuous AC mains suppression.