The basic amplifier circuit is the most basic structure in the amplifier circuit, and it is the basic unit that constitutes the complex amplifier circuit. It utilizes the characteristics of the bipolar semiconductor triode input current to control the output current, or the input voltage of the field effect semiconductor triode to control the output current characteristics to realize signal amplification. The knowledge of basic amplifier circuits in this chapter is an important basis for further study of electronic technology.
The basic amplifier circuit generally refers to an amplifier circuit composed of a triode or a field effect transistor. From a circuit point of view, the basic amplifier circuit can be viewed as a two-port network. The effect of magnification is reflected in the following aspects:
1. The amplifying circuit mainly uses the control function of the triode or the field effect tube to amplify the weak signal, the output signal is amplified in the amplitude of the voltage or current, and the energy of the output signal is strengthened.
2. The energy of the output signal is actually provided by the DC power supply, and it is only controlled by the triode to convert it into signal energy and provide it to the load.