Current type signal detection analog front end circuit

Abstract

The invention discloses a current type signal detection analog front end circuit which comprises a band-gap reference source, a current mirror, a buffer, a transimpedance amplifier and a successive approximation analog-to-digital converter, wherein the band-gap reference source is used for generating 10 microamperes current required by the current mirror and providing 300 mV bias voltage, the current mirror loads the mirror image of the 300 mV bias voltage to a magnetic sensitive biosensor array and provides an output path for detection current, the buffer is used for reducing the influence of circuit vibration on the 300 mV bias voltage, the transimpedance amplifier converts the detection current into detection voltage and amplifies the detection voltage, the successive approximation analog-to-digital converter converts the detection voltage into a digital code and outputs the digital code to DSP (Digital Signal Processor), and thus the detection is finished. According to the invention, the mode of single-chip full integration and current detection is adopted, weak variation signals in magnetic sensitive biosensors are extracted effectively, the transimpedance amplifier is used for converting the detection current into the detection voltage and amplifying the detection voltage reasonably, and finally the analog-to-digital converter outputs the digital code.

Description

technical field [0001] The invention relates to the technical field of CMOS analog integrated circuit design, in particular to a current-type signal detection analog front-end circuit. Background technique [0002] With the development of the global economy and the improvement of people's awareness of health care, the global health care industry has developed rapidly. As an important method of in vitro diagnosis, immunoassay technology has high accuracy and specificity, so it has been paid much attention in the field of clinical testing and has become one of the most important technologies in medical testing methods. The U.S. Naval Laboratory took the lead in developing the magnetically sensitive giant magnetoresistive biosensor in 1998. The biosensor was initially used for the detection and analysis of DNA factors, antigen-antibody, donor and receptor, and gradually expanded to tumors, heart disease It has the characteristics of high sensitivity and good biological specifi...

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Problems solved by technology

[0005] In view of this, the main purpose of the present invention is to provide a current-type signal detection analog front-end circuit to solve the problems of poor precision, high cost and large scale of the detection circuit of the magnetic sensitive biosensor, and achieve high precision, single chip, The purpose of total integration

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