The function of buffer in IC
The concept of buffer
The buffer has different meanings in different categories.
In the computer category, the buffer refers to the buffer storage, which is divided into two types: input buffer and output buffer. The function of the former is to temporarily register the data sent by the peripheral so that the processor can take it away; the function of the latter is to temporarily register the data sent by the processor to the peripheral. With the numerical control buffer, the high-speed working CPU and the slow-working peripheral can play the role of harmonizing and relaxing the buffer, and complete the synchronization of data transmission. Since the buffer is connected to the data bus, it must have a tri-state output function.
In other areas, there are elevator buffers, automobile spring buffers, etc., whose purpose is to slow down the speed, improve safety and warmth.
Introduction to Integrated Circuits
Microelectronics is microelectronics. It is an interleaved technical subject born out of electronics and solid-state physics. Its main task is to discuss the formation of micro-miniature electronic circuits and subsystems on solid (mainly semiconductor) materials. And systematic disciplines. Integrated circuit technology developed on the basis of microelectronics includes important components such as semiconductor data and device physics, integrated circuit and system design principles and technology, chip processing technology, function and characteristic testing technology. An integrated circuit is a system in which active components such as transistors and passive components such as resistors and capacitors are "integrated" according to a certain circuit to complete a specific circuit or function. Integrated circuits are simpler and more technological than conventional hand-assembled circuits. Firstly, they are greatly reduced in size, saving a considerable amount of space; secondly, they have inherent inevitable connections in manufacturing technology and can be processed at one time. Complete, higher technological content.
After the creation and mass consumption of transistors, various solid-state semiconductor components, such as diodes and transistors, have been widely used, replacing the functions and roles of vacuum tubes in circuits. In the mid-to-late 20th century, semiconductor manufacturing technology progressed, making integrated circuits possible. Regarding the manual assembly of circuits using individual discrete electronic components, integrated circuits can integrate a large number of microtransistors into a small chip, which is a huge improvement. The range of consumption capabilities and reliability of integrated circuits, and the modular approach of circuit design ensure the rapid adoption of standardized ICs instead of discrete transistors. IC has two main advantages with regard to discrete transistors: cost and performance. The low cost is due to the fact that the chip passes all the components through photolithography technology and prints as a unit instead of manufacturing only one transistor at a time. The high performance is due to the rapid switching of the components, which consumes less energy, because the components are small and close to each other.
Application of integrated circuits
1. Application of integrated circuit technology in the field of information technology
Information is the most important strategic resource of human society. Human beings are inseparable from the development, processing and application of information resources in all meaningful activities of understanding and transforming the world. Information Technology (Information Technology, referred to as IT) is the general term for various technologies mainly used to manage and dispose of information. It mainly uses computer science and communication technology to design, develop, install and implement information systems and application software. In today's rapid development of information technology, information technology, as a variety of technologies for managing and disposing of information, is one of the most important technological skills for human culture to move forward from time to time. Of course, computers supported by information technology hardware are indispensable, but the most important technology in computers is integrated circuit technology. Therefore, integrated circuit technology has become a key technology in the field of information technology. Since it is the most basic technical support in the entire information technology category, it directly determines the development of the information technology category. If the integrated circuit technology can provide a good integrated circuit of the central processor for the computer, then the processing speed of the computer will be considerable, and therefore the information management and processing speed will be greatly improved. When the efficiency of computer management and processing of information is improved, the development of information technology will be less restricted by hardware problems, and it will also develop better and better serve all mankind in the future. It can be seen that the application of integrated circuit technology in the field of information technology is the most critical technology in the field of information technology. Therefore, the further development and research of integrated circuit technology will not only transform the technology, but also enable the development of the field of information technology. It is well promoted.
2. Application in communication
Integrated circuits are widely used in communications, such as communications satellites, mobile phones, radars, etc. The "Beidou" navigation system independently developed by my country is a typical example.
3. Application of integrated circuit technology in the medical field
With the continuous development of human society and the continuous progress of science and technology, people’s requests for medical and health are getting higher and higher. Therefore, medical equipment and medical products based on high-tech are gradually developed, relying on high-tech electronic technology. The various treatment and monitoring skills of the company are becoming more and more advanced. Among them, integrated circuit technology is widely used in various medical equipment and medical products. This makes medical products break the constraints and limitations of traditional concepts and make better use of medical equipment. And the role of medical products, people's well-being can be improved.
4. Application of integrated circuit technology in other areas
Integrated circuit technology has universal applications in all other areas of daily life. For example, in automobiles, the application of automotive integrated circuit devices such as microcontrollers, power semiconductor devices, power management devices, LED drivers, and CCFL drivers enables automobiles to work in the best state; for example, in the field of thermal power engineering The simplest application is a temperature control meter. Of course, the information management system in a thermal power plant is inseparable from integrated circuit technology.
Buffer in the interface integrated circuit
In order to overcome the defects of poor anti-interference performance and asymmetry in the gate circuit composed of the most fundamental circuit, an inverter can be added to the output or input end as a buffer stage; an inverter can also be added to the output or input end at the same time as a buffer stage . The gate circuit composed in this way is called the gate circuit with buffer.
The output end of the gate circuit with buffered output is an inverter, and the output drive can only be determined by the tube characteristics of the output stage, and has nothing to do with the logic state of each input end. The output drive of the gate circuit without a buffer is related to the input state. On the other hand, the transfer characteristic of the gate circuit with buffer is at least the result of multiplying the 3-level transfer characteristic, so the conversion area is narrow, the shape is close to the ideal rectangle, and it does not change with the number of input terminals. With the gate circuit with buffer, the anti-interference performance is improved by 10% of the power supply voltage. In addition, the gate circuit with buffer has the advantages of symmetrical output waveform, large AC voltage gain, narrow bandwidth, and relatively small input capacitance. However, due to the additional buffer level, it also brings some defects. For example, the transmission delay time is increased, therefore, the gate circuit with a buffer is suitable for use in a high-speed circuit system.
The role of buffers in integrated circuits
The buffer is an inverter added to the input and output of the cmos gate circuit; it is mainly to make the gate circuit have a stable output resistance, better voltage transmission characteristics and a more steep output curve, imagine if there is no such inversion The simplest NAND gate circuit is that the upper two P-mos are connected in parallel, and the lower two N-mos are connected in series, then input 10 and 00 at the input end, the output should be 1, but at this time Since the upper two P tubes are connected in parallel, the output resistance is R at 10 o’clock and 0.5R at 00. The current and voltage output to the load are both unstable, but when there is an inverter at the output end, when The high-level time division of the output terminal is always R, and the low-level ground resistance is also R. Another benefit of this is that when there are multiple input terminals, such as three ports ABC, then there is no inverter To use it in the NAND gate to complete the NAND of the three, an N tube must be connected in series at the bottom, and an N tube must be connected in parallel at the top, so that when the output is 111, there will be 3 P tubes in parallel. , The low level is raised, but if you have an inverter, then there is no doubt that no matter what general method you use to combine your circuit, you always have to use an inverter to output the ground. The previous problem is not , The stable voltage transmission characteristics can be maintained! The role of the buffer in the integrated circuit The buffer storage is also called the buffer, which is divided into input buffer and output buffer. The function of the former is to temporarily register the data sent by the peripheral so that the processor can take it away; the function of the latter is to temporarily register the data sent by the processor to the peripheral. Since the buffer is connected to the data bus, it must have a tri-state output function.
The gate circuit composed of the most fundamental circuit has defects such as poor anti-interference performance and asymmetry. In order to overcome these defects, an inverter can be added to the output or input end as a buffer stage; it is also possible to add an inverter to both the output or input end as a buffer stage at the same time. on the other hand. In addition, the gate circuit with buffer has the advantages of symmetrical output waveform, large AC voltage gain, narrow bandwidth, and relatively small input capacitance.