1 integrated circuit application circuit features
â‘ most of the application circuit does not draw the internal circuit block diagram, which is detrimental to the digraph, especially for beginners for circuit analysis is more unfavorable.
â‘¡ For beginners, the analysis of integrated circuit application circuit than the analysis of discrete components of the circuit more difficult, which is the original circuit of the integrated circuit is not understand the original edge, in fact, the diagram or repair Ye Hao, integrated circuits Than discrete components circuit more convenient.
â‘¢ IC application circuit, a general understanding of the integrated circuit circuit and a detailed understanding of the role of the pin case, the diagram is more convenient. This is because the same type of integrated circuits with regularity, in possession of their commonalities, you can easily analyze many different functions with different types of integrated circuit application circuit.
2. IC application circuit diagram methods and precautions
(1) Understand the role of each pin is the key to understanding Figure understanding the role of each pin can refer to the IC application note. Knowing the role of the pins, it is convenient to analyze the working principle and components of the external circuits of the pins. For example: Know â‘ pin is the input pin, then the capacitor connected in series with â‘ pin is the input coupling circuit, and the circuit connected with pin 1 is the input circuit.
(2) three ways to understand the role of IC pins of the integrated circuit Understand the role of the pins of the integrated circuit there are three ways: First, access to relevant information; Second, according to the integrated circuit circuit block diagram analysis; Third, according to the integrated circuit application circuit In each pin external circuit characteristics analysis. The third method requires a good foundation for circuit analysis.
(3) circuit analysis steps
IC application circuit analysis steps are as follows:
â‘ DC circuit analysis. This step is mainly for power and ground pin external circuit analysis. Note: When there are multiple power pins, it is necessary to distinguish between these several power sources, for example, whether it is the power pin of the previous stage or the subsequent stage circuit or the power pin of the left and right channels; This pin also h6 distinguish. To distinguish between multiple power pins and ground pins, is useful for repair?
â‘¡ signal transmission analysis. This step mainly analyzes the signal input W pin and the output pin external circuit. When the integrated circuit has multiple input and output pins, it is necessary to find out whether it is the output pin of the previous stage or the later stage circuit. For the two-channel circuit, the left and right channel input and output pins are also distinguished.
â‘¢ other pin circuit analysis. For example, to find the negative feedback pin, pin and so anti-vibration, this step analysis is the most difficult, for beginners to take advantage of the role of pin information or internal circuit block diagram.
â‘£ With some ability to recognize images, we must learn to summarize the rules of the external circuit of the pins of various functional integrated circuits, and to grasp this rule, which is useful for improving the speed of the illustration. For example, the law of the input pin external circuit is: connected to the output terminal of the previous stage through a coupling capacitor or a coupling circuit; and the rule of the output pin external circuit is that it is connected to the input terminal of the subsequent stage through a coupling circuit
⑤ analysis of integrated circuits within the circuit signal amplification, processing, it is best to consult the IC's internal circuit block diagram. Analysis of the internal circuit block diagram, you can signal transmission line through the arrow indicates that the signal through which the circuit amplification or processing, the final signal is output from which pin.
â‘¥ understanding of some of the key test points integrated circuits, pin DC voltage regulation of the circuit is very useful. The DC voltage at the output of the OTL circuit is equal to half the DC operating voltage of the integrated circuit; the DC voltage at the output of the OCL circuit is equal to 0V; the DC voltages at the two output terminals of the BTL circuit are equal, equal to half the DC operating voltage at the single power supply, Equal to 0V. When a resistor is connected between two pins of an integrated circuit, the resistance will affect the DC voltage on the two pins. When there is a coil between the two pins, the DC voltages of the two pins are equal, When the range is inevitable, the coil is open. When there is a capacitor or RC series circuit connected between the two pins, the DC voltage of these two pins must be unequal. If the two capacitors are equal, the capacitor has been breakdown.
⑦ under normal circumstances do not go to analyze the working principle of the integrated circuit circuit, which is quite complex.
Different integrated circuit pins have different identification marks and different identification methods. It is very important for the use, purchase and maintenance test to master these marks and identification methods.
â’ˆ gap at the end of the IC has a semi-circular or square notch.
â’‰ pit, color point or sheet metal in the IC a pit, color point or sheet metal.
â’Š bevel, chamfer angle in the IC or heat sink has a chamfer angle.
â’‹ no identification mark in the entire IC without any identification mark, the general IC model face to face themselves, face up models, from left to right anticlockwise 1,2,3,4 .......
IC ICs with the reverse sign "R" Some ICs have "R" at the end, such as HAXXXXA, HAXXXXAR. The electrical properties of the two ICs are the same. Just pins are the opposite of each other.
â’ metal round-shell IC IC manufacturers of these pins have different order of arrangement, should consult the relevant information before use.
â’Ž three-terminal regulator IC: generally no identification mark, various IC have different pins. Commonly used integrated circuit quality is good or bad, a simple method of distinguishing a look: Elaborate models Marked clear handwriting Trademark and the serial number of origin and the printing quality is good (some for lacquer laser etching, etc.) Such manufacturers in the production and processing quality control More stringent. Second test: smooth pin glossy non-corroded plugging traces of short production dates regular store operations. Three measurements: Commonly used digital integrated circuits for the protection of the input and the production of the factory needs each input to the VDD GND connected to a diode (reverse) with a multimeter measuring diode level can be measured two diode effect VDD GND between the static resistance of more than 20K less than 1K is certainly bad.
Want to know the fast IC is good or bad, the available multimeter car age integrated block feet to the ground Xuan work voltage is normal, you can also remove the integrated block, measuring the integration between the feet and ground is not normal, you need Note that colleagues in the replacement of integrated circuits, we must pay attention to the welding time and the quality of welding.
Gantry Loader,Auto Loading Lathe,Cnc Lathe Gantry Loader,Gantry Loader Dual Spindle
Qingdao Jiujin Machinery Co., Ltd , https://www.jiuinmachinery.com