Low-noise weak and small signal acquisition circuit system

Abstract

The invention discloses a low-noise weak signal acquisition circuit system, and the system comprises a low-noise variable gain amplification circuit, a driving module, an adjustable active band-pass filtering network, a startup and shutdown noise reduction circuit, a power amplification module and an anti-distortion detection circuit. Aiming at the defects that weak and small signals are weak in signal driving capability, high in signal processing difficulty, easy to introduce noise in a signal processing process and the like, a variable gain amplification circuit and an anti-distortion detection circuit based on a chopping technology are adopted to adaptively improve the signal amplitude (mV magnitude), and the frequency spectrums of the signals and the noise of the amplifier are separated; a second-order adjustable active band-pass filter network is adopted to separate useful signals from noise, and the bandwidth and gain of the filter network can be flexibly adjusted; in addition, a power-on and power-off noise reduction circuit is adopted to perform power-on and power-off noise reduction on the power amplification module, and finally the whole circuit system outputs analog signals which are low in noise, high in driving capacity, certain in voltage amplitude and free of distortion.

Description

technical field [0001] The invention belongs to the field of integrated circuits, and in particular relates to a low-noise weak signal acquisition circuit system. Background technique [0002] With the rise and development of the Internet of Things, more and more smart devices have been widely used in different fields. Among them, the processing of various signals by smart devices is inseparable from sensors, and the output signals of many sensors are so weak that they cannot It is directly transmitted to the signal analysis circuit for analysis or to drive peripherals. At this time, it is necessary to amplify the weak signal. However, it is easy to introduce environmental noise and system noise in the process of signal acquisition and processing, which requires the introduction of some specific circuit structures for processing. to reduce noise. [0003] With the continuous expansion of the application scenarios of the Internet of Things, the indicators of the products of ...

AI Technical Summary

Problems solved by technology

[0009] Generally speaking, the analog output signal of the sensor is very difficult to analyze and process directly for the traditional signal analysis and processing circuit due to the characteristics of weak signal, difficult to analyze, weak signal driving ability, and easy introduction of noise in the processing process, and the whole circuit The system lacks sufficient flexibility, and may output wrong results or even stop working directly under different application requirements. This is a huge challenge for developing smart devices that can perform well in complex environments or multiple environments

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