TVS tube or transient voltage suppression diode is a new product developed in the regulator based on the technology, the circuit symbol and ordinary zener diode, the shape is no different from ordinary diode, when TVS tube ends subjected to high energy impact moment, it can at very high speed (up to 1*10-12 seconds) the impedance is suddenly reduced, while absorbing a large current, the voltage between the ends of the clamp in a predetermined value, so as to ensure that the circuit element behind from transient high energy impact damage response speed of.TVS tube than the RC loop is much faster, with the inhibition of reverse one-way TVS, there are communicate with two-way TVS. In the reverse application of prescribed conditions, when subjected to a transient overvoltage of high energy pulse, the impedance immediately dropped very low turn-on value, allowing high current through and voltage clamp to a predetermined level, so as to effectively protect the precision components in electronic circuit from being damaged. TVS diode can withstand instantaneous pulse power can reach a kW, its response time is only 1ps (10-12S) clamp. TVS diode allows the forward surge current at T = 25, T = 10ms, up to 50 ~ 200A. Bidirectional TVS can be instantaneous pulse power absorption in two positive and negative direction, and the voltage clamped to a predetermined level, two-way TVS is suitable for AC circuit, one-way TVS is generally used in DC circuit.


From the electronic related article:

　　Protection principle of TVS tube

　　TVS diode selection procedures and type selection should pay attention to the problem