Several commonly used diodes in the field of electronic components

Several commonly used diodes in the field of electronic components

Semiconductor diodes are used in almost all electronic circuits, playing an important role in many circuits and being one of the earliest semiconductor devices.

diodes are a general term for various types of electronic components. Diodes are divided into many categories, each with different functions. The following is a brief introduction to several commonly used diodes:

1、 Zener diode

A voltage regulator diode is a semiconductor device that has a high resistance until the critical reverse breakdown voltage.

The characteristic of a voltage regulator diode is that after breakdown, the voltage at both ends remains basically unchanged. In this way, when the voltage regulator is connected to the circuit, if the voltage at each point in the circuit changes due to fluctuations in power supply voltage or other reasons, the voltage at both ends of the load will remain basically unchanged.

2、 Crystal diode

The semiconductor terminal devices in the Solid-state electronics of the crystal diode. The main characteristic of these devices is their nonlinear current voltage characteristics. Subsequently, with the development of semiconductor materials and process technology, various crystal diodes with diverse structures and functional applications were developed using different semiconductor materials, doping distributions, and geometric structures. Manufacturing materials include germanium, silicon, and compound semiconductors. Crystal diodes can be used to generate, control, receive, transform, amplify signals, and perform energy conversion.

The main characteristic of crystal diodes is unidirectional conductivity, which means that under the action of forward voltage, the conduction resistance is very small; Under the action of reverse voltage, the conduction resistance is extremely large or infinite. Because of the above characteristics of diodes, cordless telephones often use them in rectifier, isolation, voltage stabilization, polarity protection, coding control, frequency modulation and noise suppression circuits.

3、 ESD diode

ESD diode, also known as ESD discharge diode, is an overvoltage and anti-static protection component designed for I/O port protection in high-speed data transmission applications. ESD protective devices are used to prevent sensitive circuits in electronic devices from being affected by ESD (electrostatic discharge). There are two types of components for ESD electrostatic protection, one is made of silicon based materials and the other is made of polymer materials! The working principle is different! Next time, we will explain in detail the differences between these two.

4、 Field-effect transistor

The field effect transistor is called Field-effect transistor for short. Conducted by a majority of charge carriers, also known as a unipolar transistor. It belongs to voltage controlled semiconductor devices. It has the advantages of high input resistance (108~109 Ω), low noise, low power consumption, large dynamic range, easy integration, no secondary breakdown, wide safe working area, etc.

5、 Varactor diode

Varactor diode is a type of diode made by utilizing the dependence and principle of PN junction capacitance (barrier capacitance) and its reverse bias voltage Vr.

A varactor diode is a special type of diode designed specifically based on the principle that the capacitance of the internal "PN junction" of a regular diode changes with the applied reverse voltage. Varactor diodes are mainly used in the high-frequency modulation circuit of mobile phones or landlines in cordless telephones to modulate low-frequency signals to high-frequency signals and transmit them. I