1. Three characteristics of TVS Diode application
1) When TVS Diode (transient suppression diode) is added to the signal and power line, it can prevent the failure of microprocessor or MCU caused by instantaneous pulse, such as electrostatic discharge effect, surge of AC power supply and noise of switching power supply.
2) The electrostatic discharge (ESD) effect can release more than 10000 V and 60 a pulses for 10 ms, while the general TTL device will be damaged when encountering 10 V pulse of more than 30 ms. TVS Diode (transient suppression diode) can effectively absorb the pulse which will cause device damage and eliminate the interference caused by the switch between buses.
3) The TVS Diode (transient suppression diode) is placed between the signal line and the ground to avoid unnecessary noise impact on the data and control bus.
2. Matters needing attention in the use of TVS diodes
The relationship between the absorbed power (peak) of the transient voltage and the pulse width of the transient voltage.
The manual gives only the absorbed power (peak) at a specific pulse width, while the pulse width in the actual circuit is unpredictable and must be estimated in advance.
The amount of wide pulse should be reduced.
For the protection of small current load, we can consciously increase the current limiting resistance in the line, as long as the resistance value of the current limiting resistance is appropriate, it will not affect the normal operation of the line, but the current caused by the current limiting resistance will be greatly reduced.
Therefore, it is possible to choose the TVS diode (transient suppression diode) with low peak power to protect the small current load line.
For the suppression of repeated transient voltages, it is particularly worth paying attention to whether the steady-state average power of TVS diodes (transient suppression diodes) is within the safe range.
How to optimize the performance of TVS diodes (transient suppression diodes) in circuits?
The wiring of printed circuit boards and the selection of circuit components are very important, through the reasonable placement of TVS diodes (transient suppression diodes), grounding selection, parasitic inductance and loop area treatment, and the comparison of avalanche TVS diodes (transient suppression diodes) and diode arrays, unidirectional and bi-directional avalanche TVS diodes (transient suppression diodes), external and internal wafer protection circuits.
The wiring of PCB and the selection of TVS diode (transient suppression diode) components are carried out scientifically and reasonably to optimize the efficiency of TVS diode (transient suppression diode).