1. Determine the maximum DC or continuous working voltage of the protected circuit, the rated standard voltage of the circuit and the "high-end" tolerance.

2. The TVS rated reverse shutdown VWM should be greater than or equal to the maximum working voltage of the protected circuit. If the VWM is too low, the device may enter an avalanche or the reverse leakage current may be too large to affect the normal operation of the circuit. Serial connection to divide voltage, parallel connection to divide current.

3. The maximum clamping voltage VC of the TVS should be less than the damaged voltage of the protected circuit.

4. Within the specified pulse duration, the maximum peak pulse power consumption PM of the TVS must be greater than the peak pulse power that may occur in the protected circuit. After the maximum clamping voltage is determined, its peak pulse current should be greater than the transient inrush current.

5. For the protection of data interface circuits, it is also necessary to pay attention to the selection of TVS devices with suitable capacitance C.

6. Select the polarity and packaging structure of TVS according to the application. It is more reasonable to choose bipolar TVS for AC circuit; It is more advantageous to use TVS arrays for multi-line protection.

7. Temperature consideration. Transient voltage suppressors can operate between -55~+150°C. If the TVS is required to operate at a variable temperature, the ID of its reverse leakage current is increasing as it increases; The power consumption decreases with the increase of the TVS junction temperature, from +25°C to +175°C, and the rain breakdown voltage VBR increases by a certain coefficient with the increase of temperature. Therefore, it is important to consult the relevant product literature and consider the effect of temperature changes on its properties.