Circuit for expanding analog input channel by utilizing code division multiple access method

Abstract

The invention relates to a circuit for expanding an analog input channel by utilizing a code division multiple access method, comprising a single multi-path analog switch chip. Each path of signal input end of the multi-path analog switch chip is connected to the analog signal input by virtue of an emitting-following filter circuit consisting of a capacitance-resistance element and an operational amplifier; an address control bus forms an address coding-gating analog detection input channel; and signals of a grating channel are directly transmitted to the analog signal input pin of a single chip microcomputer for detection by virtue of an output end. The circuit can be used at a single stage, also can be used at a plurality of single stages in series or in parallel. In the circuit, the detection quantity is far more than the analog of the quantity of analog input channels provided by the single chip microcomputer, so that the response speed is greatly improved, the power consumption is lower, and the use cost is lower.

Description

technical field [0001] The invention relates to calculation data detection technology, in particular to a circuit for expanding analog quantity input channels by code division multiple access method. Background technique [0002] The analog quantity detection input channel is a crucial peripheral part in the microcomputer detection system. It generally refers to a relatively weak voltage signal or current signal. After the signal arrangement and conversion of the external circuit, these signals are connected to the analog quantity detection provided by the microcontroller. channel for detection. However, the number of analog detection channels directly provided by the general single-chip microcomputer is often small, which is not enough to meet the needs of actual detection. Therefore, the analog quantity detection channel of the external circuit expansion system is very necessary under general detection conditions. The solution usually adopted now is to increase the syste...

AI Technical Summary

Problems solved by technology

[0003] 1. Adding additional auxiliary detection system greatly increases the volume and structure complexity of the entire detection system

[0004] 2. The communication or coding between the additional auxiliary detection system and the main detection system requires the formulation of many conditions such as protocol, timing, coding, etc. The programming is complicated, and maintenance is difficult, and the flexibility is very low

[0005] 3. The detection speed of the additionally introduced auxiliary detection system is low, coupled with the time occupied by communication and coding, it often takes a long time for the main detection system to obtain the analog detection results, which is far slower than the timing sequence of the single-chip microcomputer of the main detection system. Make the system wait too long and respond slowly

When there are many analog quantities to be detected and several auxiliary detection systems are introduced, the phenomenon of slow response is more obvious, and it will cause serious problems in occasions with high real-time requirements.

[0006] 4. Due to the addition of additional auxiliary detection systems, especially when the amount of analog detection is relatively large and several auxiliary detection systems need to be introduced to meet the detection requirements, the power consumption of the entire detection system will be greatly increased, and the system is difficult to use. Mains or battery power supply, which limits the application and scope of the system

[0007] 5. The introduction of the auxiliary detection system increases the cost of establishing the entire detection system, especially when there are many analog signals to be detected and several auxiliary detection systems need to be introduced, the increase in the establishment cost is even more serious

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