Chapter 1 Basic concepts and laws of circuits
A circuit through which current flows is called a circuit, also known as a conductive circuit. The simplest circuit consists of power supply, load, wires, switches and other elements. Circuit conduction is called a path. Only the path has current in the circuit. A break somewhere is called an open circuit or an open circuit. If there is no load between the positive and negative poles of the power supply in the circuit, it is called short circuit, which is absolutely not allowed. Another short circuit refers to the direct connection between the two ends of the element, when the current flows out from the direct connection without passing through the element. This condition is called component short circuit. Open circuit (or open circuit) is allowed, but the first short circuit is absolutely not allowed, because the short circuit of power supply will cause the power supply, electrical appliances and ammeter to burn out.
Electrical circuit or electronic circuit is the general name of electrical equipment and components connected in a certain way, which provides a path for the circulation of charges. Also called electronic circuit or electrical circuit, or network or loop for short. Such as power supply, resistor, capacitor, inductor, diode, triode, transistor, IC, key, etc. Negative charge can flow in it.
Kirchhoff's law Kirchhoff's law is the basic law of voltage and current in the circuit, and it is the basis of analyzing and calculating more complex circuits. It was put forward by German physicist G.R. Kirchhoff (1824 ~ 1887) in 1845. It can be used to analyze DC circuits, AC circuits and nonlinear circuits with electronic components. When analyzing a circuit with Kirchhoff's law, it is only related to the connection mode of the circuit, and has nothing to do with the properties of the components that make up the circuit. Kirchhoff's law includes current law (KCL) and voltage law (KVL). The former is applied to nodes in the circuit, while the latter is applied to loops in the circuit.
Chapter II Analysis Methods of Resistance Circuits
Chapter 3 Dynamic Circuit
Chapter 4 Sinusoidal Steady-State Circuits
Linear time-invariant dynamic circuit is excited by sinusoidal voltage source and sinusoidal current source with angular frequency ω. With the increase of time, when the transient response disappears, only the sinusoidal steady-state response remains, and all the voltages and currents in the circuit are sine waves with angular frequency ω, it is said that the circuit is in sinusoidal steady-state. Dynamic circuits that meet these conditions are usually called sinusoidal current circuits or sinusoidal steady-state circuits.
Chapter 2 Fundamentals of Analog Electronics Technology
Chapter 5 Semiconductors and Semiconductor Devices
Semiconductors are materials whose conductivity is between conductor and insulator at room temperature. Semiconductors are widely used in radio, television and temperature measurement.
Semiconductor: A substance whose resistivity is between metal and insulator and whose temperature coefficient of resistance is negative is called a semiconductor;
The resistivity at room temperature is about1mω cm ~1gω cm (according to Xie's electronic circuit, the upper limit is110 or10 times; Because the upper corner sign is temporarily unavailable, it is temporarily described by current method), the resistivity decreases with the increase of temperature. There are many kinds of semiconductor materials, which can be divided into elemental semiconductors and compound semiconductors according to their chemical composition. Germanium and silicon are the most commonly used elemental semiconductors; Compound semiconductors include III and V compounds (gallium arsenide, gallium phosphide, etc. ), II and VI compounds (cadmium sulfide, zinc sulfide, etc. ), oxides (oxides of manganese, chromium, iron and copper), solid solutions (gallium aluminum arsenic, gallium arsenic phosphorus, etc.). ) is composed of III-V compounds and II-VI compounds. In addition to the above crystalline semiconductors, there are also amorphous glass semiconductors and organic semiconductors.
Intrinsic semiconductor: A semiconductor without impurities and lattice defects is called an intrinsic semiconductor. At very low temperatures, the valence band of semiconductors is full (see energy band theory). After thermal excitation, some electrons in the valence band will cross the forbidden band and enter the empty band with higher energy. When there are electrons in the empty band, it will become a conduction band, and if there is one electron missing, it will form a valence band.
Positively charged vacancies are called holes. Electrons in conduction band and holes in valence band are collectively called electron-hole pairs, which can move freely, that is, carriers. They generate directional motion under the action of external electric field to form macroscopic current, which is called electron conduction and hole conduction respectively. This mixed conduction due to the generation of electron-hole pairs is called intrinsic conduction. Electrons in the conduction band will fall into holes, and electron-hole pairs will disappear. This is called recombination. The energy released during recombination becomes electromagnetic radiation (luminescence) or thermal vibration energy of crystal lattice (heating). At a certain temperature, the generation and recombination of electron-hole pairs coexist and reach a dynamic equilibrium. At this time, the semiconductor has a certain carrier density, so it has a certain resistivity. When the temperature rises, more electron-hole pairs will be produced, the carrier density will increase and the resistivity will decrease. Pure semiconductors without lattice defects have high resistivity and are not widely used in practice. The classification of semiconductors can be divided into integrated circuit devices, discrete devices, photoelectric semiconductors, logic ic, analog ic, memory and other categories according to their manufacturing processes. Generally speaking, these will be divided into small categories. In addition, there are ways to classify according to application fields and design methods. Although it is not commonly used, it is still classified by IC, LSI, VLSI and their scale. In addition, there are methods to classify signals according to their processing methods, which can be divided into analog, digital, analog-digital mixed and function.
Chapter 6: T amplifier and FET amplifier
Chapter 7 Low Frequency Power Amplifier
Chapter 8 Differential Amplifier
Chapter 9 Application of Integrated Operational Amplifier
Chapter 10 sine wave oscillator
refer to