To select a TVS diode, follow these steps:

1. Select a diode with a standoff voltage that is higher than the normal operating voltage. Ensure that the TVS diode maximum clamping voltage is less than the abs max rating of all the devices on the line to be protected. It is important to consider operation during both the transient event (a higher conduction current will result in a higher clamping voltage, for example) and during normal operation when a transient event is not present.
2. Verify that the specified peak current exceeds the expected peak current. Ensure that the diode is specified to handle the required power during a transient event. Diodes that are too small, or are not designed for a given current, may fail and cause the circuit to be destroyed during a surge or EFT event.
3. Calculate the maximum clamping voltage (V_CL) of the selected diode. TVS diode data sheets typically list the V_CL for a given IPP in the part selection table. For other peak pulse currents, however, this V_CL may not be valid. To accommodate other IPP values, the TVS diode manufacturer gives a formula in the data sheet to calculate the V_CL. Use this formula to calculate the V_CL for a given I_PP.
4. Confirm that the calculated V_CL is less than the specified abs max rating for the pin.