Analyze ESD electrostatic protection components

Analyze ESD electrostatic protection components

Any protective component must appear as a high impedance circuit at the protected input during normal operation. The capacitive load it applies must be as small as possible, so that it has almost no impact on the normal input signal. However, at the moment of overvoltage, the same device must become the main channel of energy, transferring energy from the input of the protected device. In addition, the standing off voltage of the protective device must be higher than the signal voltage allowed by the protected end. Similarly, the clamping voltage must be low enough to prevent damage to the protected device, as the voltage on the input terminal will be the clamping voltage of the protective device during transient events.

We often see the introduction of ESD electrostatic protector, ESD electrostatic impedance device, ESD electrostatic discharger, patch Varistor and other products, but in fact, the key reference coefficients of protective devices should be the following three items:

1. Quick response time

2. Low clamping voltage

3. High voltage surge withstand capacity

No matter how excellent the product is introduced, when selecting ESD electrostatic protection components, practical comparisons should still be carefully made and verified using IEC61000-4-2 testing. The current industry practice is to announce the clamping voltage based on pulses with a rise time of 8us and a duration of 20us, while the true ESD pulse should have a rise time of 1ns and a duration of 60ns.