Integrated weak electric signal filtering and amplifying circuit

Abstract

The invention discloses an integrated weak electric signal filtering and amplifying circuit, which comprises a coupling capacitance circuit, a first chopping change-over switch circuit, an operationalamplifier circuit, a second chopping change-over switch circuit, a filtering circuit, a first direct current feedback circuit, a second direct current feedback circuit, a first feedback capacitor array circuit and a second feedback capacitor array circuit. The integrated weak electric signal filtering and amplifying circuit provided by the invention can effectively eliminate DC offset of electrodes without causing distortion of a target signal, can suppress motion artifacts to a certain extent, and has configurable high-pass cut-off frequency, adjustable magnification times and low circuit noise at the same time, thereby improving the integration level and precision of the whole signal acquisition system.

Description

technical field [0001] The invention relates to the fields of sensing technology and integrated circuit technology, in particular to an integrated weak electric signal filtering and amplifying circuit. Background technique [0002] In recent years, the rapid development of sensing technology has created favorable conditions for human beings to pay attention to their own physiological signals. Accurate collection of physiological signals such as ECG, EEG, EMG, and blood pressure provides effective information support for medical research and diagnosis, and promotes the development of modern medicine. In addition, the acquisition and analysis of EEG signals can also realize a series of brain control systems and products, which are widely used in military, aerospace, industrial and entertainment fields. [0003] Physiological signals such as ECG, EEG, and EMG are essentially weak bioelectrical signals. The amplitude of these signals is generally between tens of uV and several ...

AI Technical Summary

Problems solved by technology

However, due to the electrochemical effect of the electrode, the electrode itself will introduce a DC voltage offset of up to several hundred mV, which is sufficient to cover the effective signal collected.

At the same time, because the acquisition object is in the micro-movement process, such as the contraction of breathing or the movement of the body itself, these motion artifacts caused by the human body often cause a large drift in the baseline of the acquisition circuit signal, and serious electrode offset voltage and motion artifacts have It may cause saturation of the signal acquisition channel amplification circuit and cause distortion

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