High withstand voltage instrumentation amplifier for bioelectrical signals

Abstract

The invention discloses a high-voltage-withstanding instrumentation amplifier for bioelectricity signals. The high-voltage-withstanding instrumentation amplifier comprises a signal amplification module; a modulation circuit module which is used for processing the low-impedance signals through an anti-aliasing circuit so as to prevent the low-impedance signals from being interfered by high-frequency waves; an isolation power supply module which forms a voltage doubling rectifying circuit and is used for supplying power to the signal amplification module and the modulation circuit module; and asignal isolation module which is used for reducing common-mode current in the isolation power supply module, synchronously receiving the high-frequency chopping signal and outputting the high-frequency chopping signal. By adopting high-frequency chopping and increasing the use mode of an amplifier structure, the low-noise coupling chopping amplifier achieves a very low noise level, increases common-mode voltage, eliminates output ripples of the coupling chopping amplifier, enables output of the instrument amplifier not to be interfered by ripple signals, obtains larger signal swing, and has the advantages of reducing the number of original parts, and reducing the size of an application circuit.

Description

technical field [0001] The invention relates to the technical field of biomedical electronics, in particular to a high withstand voltage instrument amplifier for bioelectrical signals. Background technique [0002] At present, ECG monitoring system, EEG monitoring system and nerve signal recording system are a research hotspot in the field of biomedical electronics at home and abroad. The recording and research of ECG signals, EEG signals and neural signals has a wide range of application values. The central electrical signals are of great significance to the detection of cardiac physiological and pathological changes. EEG signals and neural signals are useful for detecting and diagnosing neurological diseases, such as epilepsy, etc. They are of high value, and their research progress is of great significance for future neural prostheses and curing neurological diseases. A high-performance instrumentation amplifier is a critical building block for electronic systems that re...

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Problems solved by technology

[0005] However, the price of the existing low-noise and high-common-mode instruments with common three-op-amp structure is relatively high, which is mainly reflected in the relatively high requirements for the matching resistance of the third pole and difficulty in matching, and the CMRR (common-mode rejection ratio) withstand voltage is generally more than ten volts At the same time, the chopper operational amplifier structure uses more analog switches, the circuit is complex, difficult to integrate, and it is difficult to realize in the application. At the same time, the CMRR (common-mode rejection ratio) withstand voltage is generally more than ten volts to twenty volts

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