Amplifier for detecting physiological potential signal

Abstract

The invention relates to an amplifier for detecting a physiological potential signal. The amplifier comprises a transconductance amplifier 100, an input capacitor Cin1, an input capacitor Cin2, a common mode path 1001a, a common mode path 1001b, an input path 1002a, an input path 1002b, an output path 1003a, an output path 1003b, a feedback path 1004a and a feedback path 1004b. In the technical scheme of the invention, the transconductance amplifier does not need an off-chip direct current (DC) blocking capacitor; a feedback field effect transistor and a capacitor constitute a high-pass path; a DC voltage component in the physiological potential signal is filtered out; the weak physiological potential signal is amplified by a capacitance ratio; the transconductance amplifier with a full differential structure increases swing of the output signal and increases the dynamic range of the output signal; a transconductance amplifier input transistor operates in a subthreshold region and obtains the optimal power consumption and noise performance.

Description

technical field [0001] The invention relates to the field of CMOS analog integrated circuit design, in particular to an amplifier for physiological potential signal detection. Background technique [0002] In wearable physiological potential signal detection equipment, in order to extract weak physiological potential signals, the design of the amplifier located at the front end of the detection chip needs to focus on the requirements of noise and power consumption. First of all, since the amplifier is located in the first stage of signal extraction, its equivalent input noise must be 5-10μVrms lower than the background noise in order to complete the high dynamic range signal output; secondly, when the heat emitted by the circuit is greater than 80mW / cm 2 At the same time, the chip may burn the surrounding tissue cells, so the amplifier must also be designed with low power consumption to meet the application requirements of thousands of detection arrays. In the theory of ana...

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Problems solved by technology

[0003] In view of this, the purpose of the present invention is to overcome the deficiencies in the prior art, to provide a kind of amplifier for physiological potential signal detection, to solve the prior art: 1) due to the use of DC-blocking capacitors can not realize the individual capacitance and chip 2) The single-ended output structure of the amplifier limits the dynamic range of the output signal; 3) The circuit robustness is not strong due to the contradiction between noise and power consumption

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