How to select TVS diodes (ESD protection diodes)

The following describes how to select TVS diodes for typical interfaces. Follow these steps to set up a parametric search to find TVS diodes.
Click the following link to view a list of TVS diodes for automotive applications.

List of TVS diodes for automotive applications
 

Selection procedure

1. Voltage of signal Line
   What is the maximum voltage of the signal or power line to be protected?　
   Select a TVS diode with a V_RWM higher than this voltage.
2. Signal polarity
   Is the signal line to be protected a single-polarity (either positive or negative) line?　Or, is it a dual-polarity line?
   Use a bidirectional TVS diode for a dual-polarity line. For a single-polarity line, either a unidirectional or bidirectional TVS diode can be used. However, some unidirectional TVS diodes provide better ESD protection for negative-polarity signals. If an IC is destroyed even in the presence of a TVS diode, consider replacing it with a unidirectional TVS diode.
3. Signal speed
   What is the maximum frequency of the signal line to be protected?　
   A TVS diode with high total capacitance CT could degrade signal integrity. Select a TVS diode with adequate capacitance according to the signal frequency. Use the following figure as a guide to select a TVS diode with adequate capacitance.
4. Clamp voltage
   To obtain good ESD protection performance, select a TVS diode with the clamp voltage higher than the line voltage.
5. IEC 61000-4-2
   Select a TVS diode with a guaranteed ESD tolerance level higher than the system’s ESD immunity requirement. Note, however, that ESD tolerance of the TVS diode is generally proportional to its total capacitance C_T.

Use the following figure as a guide when selecting TVS diodes.

Follow the above steps to set up a parametric search.