2、 Devices: products that change the molecular structure of raw materials during production and processing are called devices.
Devices are divided into:
1. The main characteristics of active devices are: (1) their own consumption of electric energy, (2) the need for external power supply.
2. Discrete devices are divided into (1) bipolar crystal triodes, (2) field effect transistors, (3) thyristors, (4) semiconductor resistors and capacitors.
Folding resistor
The resistance is represented by "R" plus numbers in the circuit. For example, R1 represents the resistance numbered 1. The main functions of resistance in the circuit are: shunt, current limiting, voltage dividing, bias, etc.
Folding capacitor
Capacitance is generally represented by "C" plus numbers in the circuit (for example, C13 represents the capacitance numbered 13). Capacitance is an element composed of two metal films close together and separated by insulating materials. The main characteristic of the capacitor is to isolate direct current AC.
The capacity of capacitance indicates the amount of electric energy that can be stored. The blocking effect of capacitance on AC signal is called capacitive reactance, which is related to the frequency and capacitance of AC signal.
Folded inductor
Although inductors are not widely used in electronic manufacturing, they are equally important in circuits. We believe that an inductor, like a capacitor, is also an energy storage element, which can convert electrical energy into magnetic energy and store energy in the magnetic field. The inductor is represented by the symbol L. its basic unit is Henry (H), and the unit is usually millihang (MH). It often works with capacitors to form LC filters, LC oscillators, etc. In addition, people also make use of the characteristics of inductance to make choke coils, transformers, relays and so on.
Folded crystal diode
Crystal diodes are often represented by "d" plus numbers in circuits. For example, D5 represents diodes numbered 5.
Function: the main characteristic of diode is unidirectional conductivity, that is, under the action of forward voltage, the on resistance is very small; Under the action of reverse voltage, the on resistance is extremely large or infinite.
Because the diode has the above characteristics, it is often used in circuits such as rectification, isolation, voltage stabilization, polarity protection, coding control, frequency modulation and noise suppression in cordless phones.
Folding combinational circuit
Integrated circuit is a kind of device with certain functions, which is formed by integrating transistors, resistors, capacitors and other components on silicon substrate with special technology. It is abbreviated as IC, also known as chip.
Analog integrated circuit refers to an analog integrated circuit that is integrated by resistors, capacitors, transistors and other components to process analog signals. There are many analog integrated circuits, such as integrated operational amplifier, comparator, logarithmic and exponential amplifier, analog multiplier (divider), phase locked loop, power management chip, etc. The main components of analog integrated circuits include amplifiers, filters, feedback circuits, reference circuits, switched capacitor circuits, etc. Analog integrated circuit design is mainly obtained through manual circuit debugging and simulation by experienced designers, and most of the corresponding digital integrated circuit design is generated automatically by using hardware description language under the control of EDA software.
Digital integrated circuit is a digital logic circuit or system made by integrating components and wires on the same semiconductor chip. According to the number of gate circuits or components contained in digital integrated circuits, digital integrated circuits can be divided into small-scale integrated (SSI) circuits, medium scale integrated (MSI) circuits, large-scale integrated (LSI) circuits, very large-scale integrated (VLSI) circuits and very large-scale integrated (ULSI) circuits. Small scale integrated circuits contain less than 10 gates, or the number of components is not more than 100; Medium scale integrated circuits contain 10-100 gates, or 100-1000 components; Large scale integrated circuits contain more than 100 gates or more than 1000 components; VLSI contains more than 10000 gates; VLSI contains more than 100000 gates. It includes: basic logic gate, trigger, register, decoder, driver, counter, shaping circuit, programmable logic device, microprocessor, MCU, DSP, etc.
