How to select the TVS diode for the power DTU interface?

The selection of a TVS diode for the DTU interface needs to be based on the operating voltage, clamping voltage, and power. Determine the interface operating voltage Vr, for example, 24V, and select a TVS with a VRWM slightly higher than Vr, such as SMCJ24CA (VRWM=24V). The clamping voltage Vc should be lower than the withstand voltage of the protected device, such as 38.9V. The power should be selected based on the potential surge energy; for example, the SMCJ series can withstand 1500W peak pulse power. For high-speed interfaces, select a low-capacitance TVS, such as ESDLC5V0D3B (capacitance <3pF). Verify the protection effect through simulation. Correct selection ensures interface safety and prevents overvoltage damage.