Detailed steps for selecting TVS diodes

When selecting diodes, due to different application environments, it is inevitable to encounter many problems. So what are the steps for selecting TVS diodes?
1. Determine the DC voltage or continuous operating voltage of the circuit to be protected. If it is AC power, the maximum value needs to be calculated, which is the effective value multiplied by 1.414.
2. Reverse transposition voltage of TVS, i.e. operating voltage (vrwm) - select the vrwm of TVS to be equal to or greater than the operating voltage specified in step 1 above. This ensures that under normal operating conditions, the current absorbed by TVS can be ignored. If
If the voltage specified in step 1 is higher than the vrwm of the TVS, the TVS will absorb a large amount of leakage current, causing it to be in an avalanche breakdown state, thereby affecting the operation of the circuit.
3. Maximum peak pulse power: Determine the interference pulse situation of the circuit, and based on the waveform and duration of the interference pulse, determine the TVS peak pulse power that can effectively suppress interference.
4. The maximum clamping voltage (VC) of the selected TVS should be lower than the maximum allowable withstand voltage of the protected circuit.
5. Unipolar or Bipolar - There is often a misconception that bidirectional TVS is used to suppress reverse surge pulses, which is not the case. Bidirectional TVS is used for alternating current or positive and negative bidirectional pulses. TVS is sometimes used to reduce capacitance. If the circuit only has forward direction
Horizontal signal, then unidirectional TVS is sufficient. The operation mode of TVS is: during forward surge, TVS is in reverse avalanche breakdown state; In reverse surge, TVS conducts and absorbs surge energy like a forward bias diode. In low capacitance electricity

On the road, it's not like that. Bidirectional TVS should be used to protect low capacitance devices in the circuit from reverse surges.