In the actual application circuit, the damage of the instantaneous pulse to the device can not be ignored. How to protect the precision components of the post-circuit from the harm of instantaneous pulses? This requires the use of transient voltage suppressors (also known as transient suppression diodes, TVS, TVS diodes), TVS on the circuit board and the protected line in parallel. When the instantaneous voltage exceeds the operating voltage in the circuit, the TVS avalanche breakdown, giving the instantaneous current a low impedance path; When the instantaneous pulse is over, the TVS automatically restores the high impedance state, and the entire circuit returns to the normal voltage state.

Instantaneous voltage suppressor application:

In circuit safety protection, it is very important to select a suitable transient voltage suppressor. When actually using TVS transient voltage suppressors, it is important to note that:

• The influence of ambient temperature and signal frequency on junction capacitance must be considered. As the operating temperature rises, the leakage current increases, the power decreases, and the breakdown voltage increases, especially the junction capacitance changes greatly with the temperature.

• The TVS tube manual gives only the absorbed power under a specific pulse width, but the pulse width in the actual line is unpredictable, which should be estimated in advance, and the wide pulse should be derated.

• In the protection of small current loads, it is necessary to consciously increase the current limiting resistance in the line;

• For the suppression of recurring transient voltages, particular attention should be paid to whether the steady-state average power of the transient voltage suppressor is within the safe range.