When maintenance components are operating normally, they need to be used as high-impedance circuits to minimize their capacitance load on the input side being maintained, ensuring that there is no impact on the normal input signal.

However, during overvoltage transient moments, the same equipment needs to become the primary path for energy and transfer energy from the input end of the maintained equipment. In addition, the safety voltage of the maintenance equipment must be higher than the maximum signal voltage allowed on the maintained end.

Similarly, the clamping voltage must be low enough to avoid damage to the maintained equipment, as the voltage on the input end will be the clamping voltage of the maintenance equipment during the transient period.

We often see products that introduce ESD static protectors, ESD static impedance resistors, ESD static release devices, surface-mount varistors, and other products. However, in fact, the most critical reference factors for maintenance equipment should be the following three items:

1. Rapid response time

2. Low clamping voltage

3. High surge current withstand capacity

Regardless of how good the product is introduced, when selecting ESD static maintenance components, practical comparisons should still be made carefully, and IEC61000-4-2 testing should be used to verify.

The current industry practice is to release the clamping voltage based on a pulse with an 8us rise time and a 20us duration, while the actual ESD pulse should have a rise time of 1ns and a duration of 60ns.

In summary, the advantages and disadvantages of the above ESD static protectors and maintenance components are mainly analyzed from several aspects such as polymer equipment, varistors, suppressors, and semiconductor diodes. It is hoped that the explanation in this article will have significant reference value for everyone's work.