Varistors and TVS differences

The varistor is a non-linear volt-ampere resistance device. Most of the varistors are used for voltage circuit protection when the circuit is under overvoltage, and absorb excess current to protect sensitive devices. Often referred to as VDR. The resistor body of the varistor is a semiconductor, so it is one of the semiconductor resistors.

TVS (diode), also known as transient suppression diode, is a widely used new type of efficient circuit protection device with a very fast response time and very high surge absorption characteristics. When it is subjected to an instantaneous high-power shock at both ends, the TVS can change the impedance value between the two ends from a high impedance to a low impedance at an extremely high speed to absorb an instantaneous large current.

What is the difference between varistors and tvs?

1, varistors have small size, do not take up local, low cost and other factors. The TVS strongly limits the voltage and is relatively expensive.

2. The nonlinear characteristics of the TVS tube is the same as that of a zener diode. The leakage current before breakdown is very small. After the breakdown, it is a regulated voltage characteristic. Compared with a varistor, the TVS tube has a maximum strength limit voltage deviation from the breakdown voltage. Better than varistors, but the flow characteristics are smaller than varistors.

3, varistor reliability, not easy to degrade, long service life. TVS pipes have poor reliability, aging, and short service life.

4, varistors can accept greater inrush current, and the larger the volume can withstand the surge current, the maximum up to tens of K amps to hundreds of K amps; but the nonlinear characteristics of varistors Poorer, higher current limit voltage, lower leakage current at higher voltage.

5. In terms of response rate, the response speed of the TVS tube is faster, which is PS level, while the varistor response speed is slower, which is NS level. In addition, the varistor and TVS have large capacitances.