Finding a complete tutorial for digital and analog circuits? 50

Is our country's education system a waste of money ?

Countries have their own environments and cultural traditions, and they cannot be generalized. The textbooks and courseware of the Massachusetts Institute of Technology in the United States are published on the Internet free of charge, and the Chinese around the world are also obliged to translate, anyone can go to learn, and there are more people who can pass the exam, how many countries can be like him? Academicians, postdoctoral fellows, and doctoral supervisors also come to class, which is known for their faintness.

In the past, I used to go deep into the student dormitory, guide students to learn analog circuits for free, and purchase components, materials, liquid crystal display boards, and computers for them to conduct experiments at their own expense, tutor them to build mathematical models for free, and guide them to write invention patent documents for free.

For general experimental problems, guide them to solve them on the spot. Even for students whose families can afford to do so, cash support that does not have to be repaid has been provided.

If a student is really interested in this profession, has something to know, has any doubts, or encounters any problems that cannot be solved, just come to me and ask me, as long as I know and have personal experience, I know everything and say everything, and I will answer it immediately without reservation.

Because of this, he offended Hu Jun, and he still persevered after being forced to be laid off.

I have but the file is relatively large, it is not easy to transmit, you can check the analog electronics of the University of Petroleum on the Internet, and the digital circuit of the University of Petroleum, if necessary, I have a complete analog circuit courseware, if you need to leave me a message.

Modular electricity is an analog circuit; Digital electricity is a digital circuit.

Digital circuits are based on analog circuits, which are based on current and voltage. The current and voltage of an analog circuit are constant for a cycle, while the current and voltage of a digital circuit are fluctuating.

Analog circuits and digital circuits are also carriers of signal changes, analog circuits in the circuit to the signal slip amplification and reduction through the amplification characteristics of components (such as transistors) to achieve operation, and digital circuits are the transmission of signals through the switch characteristics to achieve operation.

Digital circuits. Circuits that perform arithmetic and logical operations.

A circuit that uses a digital signal to perform arithmetic operations on digital quantities is called a digital circuit, or digital system.

Because it has the functions of logic operation and logic trembling processing, it is also called a digital logic circuit.

Modern digital circuits are constructed from several digitally integrated devices made in semiconductor processes.

A logic gate is the basic unit of a digital logic circuit.

Memory is a digital circuit used to store binary data.

On the whole, digital circuits can be divided into two categories: combinatorial logic circuits and sequential logic circuits.

Analog circuits. It is a circuit used to process analog signals (signals that are continuous in time and amplitude, such as the voice signal you hear from the speaker when you listen to the radio, watch TV, and play **).

The counterpart is digital circuitry.

But analog circuits are the basis of digital circuits, and the devices of digital circuits are composed of analog circuits!

An analog circuit is a circuit that processes analog signals; A digital circuit is a circuit that processes digital signals.

An analog signal is a function of time and is a continuously changing quantity, while a digital signal is a discrete quantity. Because all electronic systems are based on specific electronic devices and electronic circuits, in a signal processing, the acquisition of signals and the recovery of signals are analog signals, and only the processing of the middle part of the signal is digital processing. Specifically, analog circuits mainly deal with analog signals, which do not change with time, and are continuous signals in both time domain and value domain, such as voice signals.

On the contrary, digital signals are changing, and the processing of digital signals includes the sampling of signals, the quantization of signals, and the coding of signals.

However, if digital signal transmission is adopted, a kind of coding should be used, and the sound size of each level corresponds to a code, and at the sound input end, every time a sample is taken, the corresponding code is transmitted. It can be seen that no matter how many levels the sound is divided into, no matter how high the sampling frequency loss rate is, there is still a loss in this way for the original sound. However, this loss can be compensated for by increasing the sampling frequency, and theoretically the sampling frequency of the pure He God is greater than twice the frequency of the original signal.

Generally speaking, the difference between analog and digital is essentially the difference between analog and digital signals

1. The working principle of the signal source is different.

Analog signal is a signal that simulates the change of information (such as sound information, image trace information, etc.); Digital signals, on the other hand, are sampled, quantized, and encoded to form digital signals (also known as pulse signals).

2. Different output methods.

Analog signals are generally transmitted through traditional transmission lines (such as ** network, cable TV network). When a digital signal is represented by intermittent voltage or optical pulses, it is generally necessary to connect the two sides of the communication with twisted pair cables and optical fiber media to pass the signal from one node to another.

3. The signal status and mode are different.

A digital signal is a signal in which the independent variable is discrete and the dependent variable is also discrete, the independent variable of this signal is represented by an integer, and the dependent variable is represented by a number in a finite number. In computers, the magnitude of a digital signal is often expressed as a binary number with limited bits.

An analog signal is a signal in which an information parameter behaves as continuous within a given range. or in a continuous interval of time, the characteristic quantity of the information can be presented as a signal with any numerical value at any instant.

Modular electricity is an analog circuit; Digital electricity is a digital circuit.

Digital circuits are based on analog circuits, which are based on current and voltage. The current and voltage of an analog circuit are constant for a cycle, while the current and voltage of a digital circuit are fluctuating.

Analog circuits and digital circuits are also carriers of signal changes, analog circuits amplify and reduce signals in the circuit through the amplification characteristics of components (such as transistors) to achieve operation, and digital circuits are the transmission of signals through switching characteristics to achieve operation.

The difference between the two:

In analog circuits, voltage. Current. The changes in frequency, period are mutually restrictive, and the voltage in the circuit in a digital circuit. Current. Frequency. The change in the cycle is discrete.

Analog circuits can work at high current and high voltage, while digital circuits only work at low voltage, low current bottom power consumption, complete or produce stable control signals.

The simulated circuit is to supply power to the digital circuit and complete the execution of the actuator. The digital circuit is to complete the operation process of the entire circuit through its unique logic operation, so the boundary between the digital circuit and the analog circuit is clear in the maintenance, which can be handy and convenient.

Difference one

Differences in signal change characteristics. The size of the analog signal in an analog circuit changes continuously over time. The digital signal in a digital circuit is discontinuous with time and is an intermediate break in a discrete-time signal sequence (or pulse train).

For analog circuits, more attention is paid to the specific values of voltage and current, and for digital circuits, more attention is paid to the level.

Difference two

Differences in signal processing methods. The signal processing of analog circuits is mainly realized by the amplification characteristics of MOSFETs, which also include electronic components such as resistors, capacitors, diodes, and bipolar transistors.

In the end, it is realized by a network composed of a certain mathematical model. Such as familiar analog signal processing, such as measurement bridges, signal amplification and filtering, modulation and demodulation, signal conversion and AD transformation.

The signal processing of digital circuits is mainly realized by the switching characteristics of the FET, through which the basic AND NAND gate circuits, flip-flops, and arithmetic logic units are used to complete complex arithmetic operations and logical operations.

Difference three

Differences in anti-interference capabilities. It can be seen from the analog circuit and the digital circuit that the digital circuit quantifying the signal beam is stronger than the analog circuit, has stronger signal anti-interference ability, stronger noise resistance ability, and higher signal accuracy.

The reason is that the signal in the analog circuit is almost in the form of voltage and current in a certain proportion of the real signal, so that the sensitivity of the analog circuit to noise is stronger than that of the digital circuit. The analog signal in the analog circuit will change through several changes and long-distance transmission, and the signal waveform will change, which will cause the signal loss, so the anti-interference ability of the analog circuit is weaker than that of the digital circuit cavity.