The rated transient power of the TVS product should be larger than the maximum transient surge power that may occur in the circuit, which can be referred to as the following calculation method.

Vc clamping voltage
Transient safety voltage TVS a voltage should be less than the level after the protected circuit can withstand the maximum avalanche breakdown voltage and Ipp, Vc and TVS are proportional to the. For the TVS tube of the same power level, the higher the breakdown voltage, the higher the VC.
IR leakage current
For some communication circuits and low power circuits, special attention should be paid to IR, and IR can not affect the efficiency and normal work of the system. General voltage TVS leakage current will be larger, if the voltage allowed, as far as possible to select more than 10V TVS tube, leakage current will be relatively small. If we must choose the TVS tube with low voltage and low current, we can also provide the TVS tube with low leakage flow, and we can also provide the TVS products with low leakage flow.
Junction capacitance
The junction capacitance of TVS tube in a few general piene method. For the TVS of the same power level, the lower the voltage, the greater the value of the capacitance. In some communication lines, it is necessary to pay attention to the junction capacitance of the TVS tube, which can not affect the normal operation of the line.
Packaging form
The power of TVS can also be reflected from the form of encapsulation. The smaller the package size is, the smaller its power is, because the chip area of TVS directly determines the power level of TVS. The circuit engineer can select the appropriate package TVS devices according to the circuit design and test requirements.