The varistor is a widely used voltage-limiting electronic component. Using the nonlinear volt-ampere characteristics of the varistor, when an overvoltage occurs between the two poles of the varistor, the varistor can clamp the voltage to a Relatively fixed voltage value, so as to realize the protection of the subsequent circuit. Since the resistive body material of the varistor is a semiconductor, the varistor is also a semiconductor electronic component.
When purchasing varistors, we need to understand the parameters of varistors so as to choose the appropriate varistor model.
However, there are several terminology about varistors that you may not know.
Leakage current: In addition to the discharge gap, the microampere-level current passed by the SPD after it is connected in parallel to the line, usually 0.75 times the DC reference voltage in the test, is an important parameter index of the deterioration degree of the varistor
Varistor voltage: refers to the breakdown voltage or threshold voltage, which refers to the voltage value of the varistor under the specified current. In most cases, the voltage value measured when 1mA DC current is passed through the varistor, the varistor voltage range of its products can range from 10-9000V, and can be selected correctly according to specific needs.
Junction capacitance: A capacitance present in electronic components caused by an electric field between two conductors. In varistors, junction capacitance refers to the capacitance inside the varistor. When the voltage changes, an electric field will be generated inside the varistor, which will cause the junction capacitance inside the varistor to change, thereby affecting the resistance value of the varistor.
The junction capacitance of the varistor has a great influence on its response time and high-frequency characteristics, because the junction capacitance will limit the response speed and high-frequency characteristics of the varistor. When varistors are used in high-frequency circuits and digital circuits, their response time and high-frequency characteristics may be limited, which will cause signal distortion and errors, so varistors are rarely used in high-frequency circuits and digital circuits middle.
This article is provided by JYH HSU (Dongguan Zhixu) Electronics, which is a manufacturer of electronic components in China. Its capacitors have various certifications and are reliable in quality. Welcome to inquire.
Post time: May-22-2023