Definition and role of TVS

Definition of TVS

TVS or transient voltage suppression diode is a new product developed on the basis of Zener diode technology. When the two poles are subjected to reverse transient high-energy shock, it can change the high impedance between the two poles into a low impedance at a speed of 10-12 seconds, absorb surge power up to several kilowatts, and make the voltage between the two poles. Clamped at a predetermined value, it can effectively protect the precision components in the electronic circuit from damage by various surge pulses.

TVS features

TVS tube has been widely used because of its advantages of fast response time, large transient power, low capacitance, low leakage current, small breakdown voltage deviation, easy control of clamping voltage, no damage limit, small size and easy installation. In computer systems, communication equipment, consumer electronics, power supplies, household appliances and other fields.

Application of TVS

1. The application of TVS can effectively suppress the overload pulse brought by the power grid, so as to protect the rectifier bridge and all components in the load.

2. Protect the DC regulated power supply with TVS. At the same time, it can also absorb the peak voltage between the collector and the emitter of the transistor in the circuit, thereby protecting the transistor. It is recommended to add a TVS tube at the output end of each voltage regulator, which can greatly improve the reliability of the whole machine.

3. Protect the transistor circuit with TVS. Various transient voltages can make the EB junction or CE junction of the transistor break down and damage, especially when the collector of the transistor has an inductive (coil, transformer, motor) load, a high-voltage back EMF is usually generated, which may damage the transistor. In practical applications, it is recommended to use TVS as a protection device.

4. Protection of integrated circuits. As the integration level of modern ICs is getting higher and higher, and its withstand voltage is getting lower and lower, it is easy to be damaged by the impact of transient voltage, so protective measures must be taken. Usually, there are protection networks at the input and output ends of the CMOS circuit. For the sake of reliability, various protection networks are also added to the external interfaces of the whole machine.

5. Protect the integrated op amp with TVS. Integrated op amps are very sensitive to external electrical stress. Therefore, in the process of using the op amp, if the operation error or abnormal working conditions are adopted, there will often be excessive voltage or current, especially surge and electrostatic pulse, which will easily damage the op amp or cause damage to the op amp. invalid.


Therefore, the precision components in the electronic circuit can be effectively protected. Then bidirectional TVS can absorb instantaneous large pulse power in both positive and negative directions, and clamp the voltage to a predetermined level. Bidirectional TVS is suitable for AC circuits, and unidirectional TVS is generally used for DC circuits. It can be used for anti-lightning, anti-overvoltage, anti-interference, absorbing surge power, etc. It is an ideal protection device.

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