TVS diodes are generally used to prevent the damage of the back-end circuit caused by the instantaneous voltage shock of the port. Prevent the instantaneous voltage shock of the port from causing damage to the rear circuit. There are one-way and two-way, one-way TVS is generally used in DC power supply circuit, two-way TVS is used in AC power supply circuit.
The rated transient power of TVS products should be greater than the maximum transient surge power that may occur in the circuit, in theory, the greater the power of TVS, the better, can withstand more impact energy and times, but the higher the power, the larger the package of TVS, the higher the price, so the power of TVS can meet the requirements.
Features of TVS diode
High performance protection device in the form of diode. In consumer product applications, both the voltage regulator and TVS tube are used, and the voltage regulator is a very common diode. It is also a standard semiconductor device mentioned in college textbooks, including all electronics books. TVS is a diode developed on the basis of the voltage regulator, which focuses on the instantaneous surge discharge ability and does not require high reverse breakdown voltage consistency.
The circuit symbol of TVS is the same as that of ordinary voltage regulator diodes. Its forward characteristic is the same as that of ordinary diode; The reverse characteristics are typical of PN junction avalanche devices.
The most notable feature of TVS diodes is that they respond quickly, so that the instantaneous pulse is effectively contained before causing damage to the line or device, and the second is that the cut-off voltage is relatively low, which is more suitable for battery-powered low-voltage loop environments. In addition, the improvement of TVS diode design enables it to have lower leakage current and junction capacitance, so it has better performance in dealing with electrostatic shock of high rate conduction circuit.
TVS diode operation principle
When the poles of the TVS diode are subjected to reverse transient high energy impact, it can change the high impedance between the poles into low impedance at a speed of 10 to the minus 12 seconds, absorbing up to several kilowatts of surge power, so that the voltage clamp between the poles is located at a predetermined value, effectively protecting electrons
Precision components in the line are protected from damage by various surge pulses.
TVS diode and the common voltage regulator diode working principle is similar, if higher than the breakdown voltage on the sign, TVS diode will be on, compared with the voltage regulator diode, TVS diode has a higher current conduction ability. When the poles of the TVS diode are subjected to a reverse transient high energy impact, the high impedance between the poles is changed to a low impedance at a speed of 10-12S, while absorbing up to several kilowatts of surge power. The voltage clamp between the poles is located at a safe value, which effectively protects the precision components in the electronic circuit from the damage of the surge pulse.
TVS is mainly used for fast overvoltage protection of circuit components. It can "absorb" surge signals with power up to several kilowatts.