The protection principle of the pressure sensitive resistor (MLV/MOV), the application of TVS pipe and the pressure sensitive resistance
The protection principle of the pressure sensitive resistor (MLV/MOV), the application of TVS pipe and the pressure sensitive resistance
First, the pressure sensitive resistance (MLV/MOV)
MLCV (MLV) and metal oxide varistor (MOV) using ZnO varistor varistor material, to achieve the protection of the electrostatic resistance material, varistor is a semiconductor, when applied to the varistor voltage is less than the varistor voltage, voltage sensitive resistor is equivalent to 10M above the insulation resistance when applied; a voltage greater than the breakdown voltage of the varistor at the ends, a sharp decline in resistance of varistor has low resistance, so as to guide the rapid charge, effectively protect the other components in the circuit is not caused by overvoltage and damage. The varistor is used in physical absorption principle, so after each ESD event, the material will be some form of physical damage, leakage can not be restored, will decrease with increasing frequency of use performance, life limitation. Shanghai Lei Mao Electronics
The pressure sensitive resistor supports bidirectional protection, and its volt ampere characteristics are completely symmetrical, VW: normal operating voltage (Voltage Working). IL: the maximum Vw operating conditions of the leakage current (Current Leakage). The failure mode of varistor is mainly short circuit, but when the over current is too large, may cause the valve to be open and burst.
Two, TVS tube and pressure sensitive resistance applications
Through the performance comparison of the TVS tube and the pressure sensitive resistance, according to their respective advantages, suitable for application occasions:
1, compared with a varistor, TVS tube with fast response time, clamp voltage deviation, small junction capacitance, reverse leakage current has the advantages of small and no life limit, so it is suitable for the requirement of high quality, signal line leakage requirements ESD protection small interface, such as high-speed data signal transmission line and the clock line etc..
2, and TVS comparison, varistor breakdown voltage VBR and clamp voltage VC are relatively high, the flow capacity is relatively strong, the surge pulse absorption ability of ESD, which is suitable for surge protection or power supply interface.
3, the two are suitable for the occasion, consider the price factor, the use of pressure sensitive resistance.
From the electronic related article:
Selection of pressure sensitive resistance: selection of nominal voltage and flow rate of the pressure sensitive resistance
The characteristics of the pressure sensitive resistance and the application field of the pressure sensitive resistance