TVS Diode Supplier

What are TVS Diodes?
Transient voltage suppression diode (Transient voltage suppression diode), also known as TVS diode, is a high-efficiency electronic protection device in the form of a diode. It can protect electrical equipment from being damaged by voltage spikes introduced by wires.

Basic information of TVS diodes

Pulse peak power Pm: The pulse peak power Pm refers to the product of the pulse peak current IPP of the 10/1000μs wave and the maximum clamping voltage VC, that is, Pm=IPP*VC.

Characteristics of TVS Diodes

TVS is a high-efficiency protection device in the form of a diode. When the two poles of the TVS diode are impacted by reverse transient high energy, it can change the high impedance between its two poles to low impedance at a speed of 10 minus 12 seconds, absorbing up to several thousand watts of surge power . The voltage between the two poles is clamped at a predetermined value, which effectively protects the precision components in the electronic circuit from being damaged by various surge pulses. Because it has the advantages of fast response speed, large transient power, low leakage current, small breakdown voltage deviation, easy control of clamping voltage, no damage limit, and small size. Has been widely used in computer systems, communication equipment, AC/DC power supplies, automobiles, electronic ballasts, household appliances, instruments (watt-hour meters), RS232/422/423/485, I/O, LAN, ISDN, ADSL, USB, MP3, PDAS, GPS, CDMA, GSM, digital camera protection, Common mode/differential mode protection, RF coupling/IC driver receiving protection, Motor electromagnetic wave interference suppression, audio/video input, sensor/transmission, Industrial control circuit, relay, contactor noise suppression and other fields.

The main difference between TVS diodes

Transient interference of voltage and current is the main cause of damage to electronic circuits and equipment, and often brings incalculable losses to people. These disturbances usually come from the start-stop operation of power equipment, the instability of the AC power grid, lightning strike interference and electrostatic discharge, etc. Transient interference is almost everywhere and all the time, making people feel unpredictable. Fortunately, the emergence of a high-efficiency circuit protection device TVS has effectively suppressed transient interference. TVS (Transient Voltage Suppressor), or transient suppression diode, is a new product developed on the basis of Zener technology. Its circuit symbol is the same as that of ordinary Zener diodes, and its shape is no different from that of ordinary diodes. When the two ends of the TVS tube are subjected to an instantaneous high-energy impact, it can suddenly reduce its impedance at a very high speed (up to 1/(10^12) seconds) and absorb a large current at the same time. The voltage between its two ends is clamped at a predetermined value, so as to ensure that the subsequent circuit components are not damaged by the impact of transient high energy. If it is used, TVS has diodes and varistors. I personally think that varistors have more advantages and are widely used in mobile phones, LCD modules, and some more sophisticated handheld devices. In particular, products exported to Europe generally have to be added as one of the main means of electrostatic protection.
Both TVS and Zener voltage regulator can be used as voltage regulators, but the Zener breakdown current is smaller, and the voltage regulator greater than 10V is only 1mA. Relatively speaking, it is much larger than the breakdown current of the Zener diode, but the voltage regulation accuracy of the Zener diode can be made relatively high.
In the circuit, it generally works in the reverse cut-off state, and it does not affect any function of the circuit at this time. Under the specified reverse application conditions, when there is a large transient interference voltage or pulse current in the circuit due to lightning and various electrical interference, it will be in a very short time (up to 1 × 10-12 seconds) ) quickly turn into the reverse conduction state, and clamp the voltage of the circuit at the required safe value, thus effectively protecting the precision components in the electronic circuit from damage. After the interference pulse passes, the TVS turns into the reverse cut-off state again. Since its clamping voltage is lower than the highest withstand voltage of other devices in the circuit during reverse conduction, it protects other components. The instantaneous pulse power that TVS can withstand can reach thousands of watts, and its clamping time is <1ns. TVS can be divided into unidirectional and bidirectional TVS according to polarity. Unidirectional TVS is generally applicable to DC circuits, and bidirectional TVS is generally applicable to AC circuits. Because TVS acts quickly, has a long life and is easy to use when it plays a protective role, it has a very wide range of applications in the field of transient voltage protection.
The parameters are described as follows:
1. Breakdown voltage V(BR)
2. Maximum reverse pulse peak current Ippm
3. The maximum reverse working voltage VRWM
4. The maximum clamping voltage VC(max)
5. Reverse pulse peak power Pppm
6. Capacitor CPP
7. Leakage current IR

Comparison of TVS Diodes and Zinc Oxide Varistors

Electrostatic discharge (IEC61000-4-2), transient voltage, click (IEC61000-4-4) EFT, and surge voltage immunity (IEC61000-4-5) are essential in electronic applications ) for protection. In order to protect the safety and reliability of electronic circuits, in the field of protection, there are two kinds of protection components, one is a TVS semiconductor diode with avalanche characteristics, and the other is a multilayer varistor. In order to use rationally, it is necessary to compare TVS and MOV in order to select correctly and achieve the optimal selection of product design.
PROTEK's TVS semiconductor diode is designed with a highly sensitive N/P junction. Its characteristic is to produce an avalanche effect, which is proportional to the junction area of the semiconductor. By controlling the doping concentration of the junction area and the resistivity of the substrate, it can absorb a large amount of transient current and generate an avalanche characteristic, thereby controlling the ability of the surge current. It is a high-tech product with special manufacturing process.
The multilayer varistor is to press the zinc oxide material into the rectangle to form a multi-grain structure, which is divided into multiple layers to form a more uniform control area. It is a special component to realize the ability to absorb surge current through the change of conduction resistance.
Both avalanche breakdown diode TVS and multilayer zinc oxide varistor rely on changing their own blocking characteristics to control electrostatic discharge, transient voltage and surge voltage, and the main difference is the blocking after conduction. TVS is controlled by a highly sensitive N/P junction, and its conduction resistance is very low. The turn-on resistance of MOV is much higher than that of TVS, which leads to differences in clamping voltage and clamping ratio.

Specifications of TVS Diodes

TVS diodes have the following specifications:
     Leakage current: The current that can be turned on when the voltage is less than the maximum reverse turn-off voltage.
     Maximum reverse turn-off voltage: Below this voltage, the conduction current is not obvious
     Breakdown voltage: The voltage at which significant conduction current occurs.
     Clamping Voltage: The voltage at which the conduction current will reach its rated current (hundreds to thousands of amperes).
     Stray Capacitance: A non-conducting diode behaves like a capacitor and has a destructive effect on high frequency signals. It is generally recommended to use TVS diodes with lower stray voltage.
     Stray inductance: Since the switching of the actual overvoltage is fast, the inductance of the package is one of the limiting factors for the reaction speed.
     Absorbable energy: Because the transient is very short, all the energy becomes heat in the TVS diode itself. The heat sink will only affect the time required for subsequent heat dissipation, and cannot increase the energy that the TVS diode can absorb. Therefore, a high-energy TVS diode will also have a larger volume. If the volume is not large enough, the overvoltage may destroy the TVS diode, and it will not be able to protect other circuits.