4 Selection guidelines for TVS diodes (ESD protection diodes)

In order to choose the right ESD protection diode, pay attention to the key electrical characteristics described in Section 3.

1. Maintaining the quality of the signals to be protected
a) Signal line voltage
Select ESD protection diodes with appropriate reverse breakdown voltage (V_BR) or working peak reverse voltage (V_RWM) according to the maximum voltage of the signal lines to be protected.
b) Signal polarity
Use bidirectional ESD protection diodes for signals that cross the GND level such as analog signals.
c) Signal speed
Select ESD protection diodes with appropriate total capacitance (C_T) according to the maximum frequency of the signal lines to be protected.

2. Enhancing ESD protection performance
d) Dynamic resistance
Select ESD protection diodes with dynamic resistance (R_DYN) as low as possible.
e) Clamp voltage
Select ESD protection diodes with the minimum clamp voltage (V_C) according to the V_RWM required.
Be sure to choose diodes with V_C lower than the withstand voltage of the device under protection.

3. ESD tolerance of ESD protection diodes
f) IEC 61000-4-2
Select ESD protection diodes with a guaranteed ESD performance higher than a system’s ESD immunity requirement.
Note, however, that the ESD performance of the ESD protection diode is generally proportional to its total capacitance.
g) IEC 61000-4-5
Select ESD protection diodes with electrical ratings higher than the peak pulse power and peak pulse current requirements.