The circuit symbol of a TVS is the same as that of a normal regulator diode. Its forward characteristics are the same as those of ordinary diodes; The reverse characteristics are typical of PN junction avalanche devices.

When the current flowing through the TVS rises from the original reverse leakage current ID to the IR under the action of the transient peak pulse current, the voltage presented by the two poles rises from the rated reverse shutdown voltage VWM to the breakdown voltage VBR, and the TVS is broken down. With the occurrence of peak pulse current, the current flowing through the TVS reaches the peak pulse current IPP.

The voltage at its poles is clamped below the predetermined maximum clamping voltage. Then, as the pulse current decays exponentially, the voltage at the TVS poles decreases until it returns to its starting state. This is the entire process by which the TVS suppresses the power of the surge pulses that may occur, protecting the electronic components.