Detection and processing circuit for biological weak signal

Abstract

The invention discloses a detection and processing circuit for a biological weak signal. The detection and processing circuit comprises a program-controlled filter circuit, a differential amplification circuit and low pass filters (LPF); the program-controlled filter circuit is formed by an operational amplifier AMP_1 and the low pass filters which are respectively formed by connecting a resistor with a capacitor in parallel; the program-controlled filter circuit is used for performing range-by-range detection and filtering on weak current; the differential amplification circuit is connected with the program-controlled filter circuit, and can be used for completing differential amplification of a converted small voltage signal and removing differential common-mode voltage so as to achieve the tail-to-rail function of output voltage; the low pass filters LPF are connected with the differential amplification circuit so as to filter off power line interference and high-frequency noise. According to the detection and processing circuit for the biological weak signal, disclosed by the invention, weak signal current different in magnitude is detected grade by grade by adopting program-controlled filtering so as to increase signal to noise ratio; meanwhile, a common-mode signal is filtered off by adopting differential amplification, and then, filtering is performed so as to increase the amplitude of the weak signal; the detection effect is good.

Description

technical field [0001] The invention relates to a biological weak signal detection which adopts program-controlled filter classification to detect weak signal currents of different magnitudes to improve the signal-to-noise ratio, and uses differential amplification to filter out common-mode signals and then filter to improve the amplitude of weak signals and processing circuitry. Background technique [0002] The detection and processing of weak signals mainly includes two aspects. One is to adopt hardware measures at the front end of the data acquisition system to filter out noise and increase the proportion of weak signals, which is convenient for subsequent signal extraction; on the other hand, software processing is used. After the front end of the acquisition system performs some simple filter processing, the collected signal is sent to the single-chip microcomputer system, and then after some software filter processing, the weak signal is detected. These two detection...

AI Technical Summary

Problems solved by technology

However, because the measured signal is very weak, the background noise of the sensor, the inherent noise of the amplifier circuit and the measuring instrument, and the external interference noise are often much larger than the amplitude of the useful signal.

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