Analog front end detection circuit used for giant magneto-resistive (GMR) biosensor

Abstract

The invention relates to an analog front end detection circuit used for a giant magneto-resistive (GMR) biosensor. The circuit comprises a bandgap reference voltage source, a sensor voltage generating circuit, a 5bit reference voltage generating circuit, a charge transfer switched capacitor sampling / holding circuit and a pipelined analog-to-digital converter. The analog front end detection circuit has the following beneficial effects: the methods of single chip total integration and voltage detection are adopted, thus effectively extracting the weak voltage signals in the GMR biosensor; the charge transfer switched capacitor sampling / holding circuit is utilized to sample the detection voltage of the resistor array of the GMR biosensor and reasonably amplify the detection voltage to the input voltage range of the analog-to-digital converter; and finally, the analog-to-digital converter is used for outputting the digital detection results.

Description

technical field [0001] The invention relates to the technical field of CMOS analog integrated circuit design, in particular to an analog front-end detection circuit for giant magnetoresistive biosensors. Background technique [0002] The giant magnetoresistance (GMR) biosensor was first developed by the US Naval Laboratory in 1998. It was initially used for the detection and analysis of DNA factors, antigen-antibodies, donors and receptors. At present, it is gradually extended to tumors, cancers and other diseases. Immunodiagnosis, environmental monitoring, and detection and prevention of epidemic viruses are high-tech developed by cross-infiltration of biology, chemistry, physics, medicine, microelectronics and other disciplines. The technology has the characteristics of high sensitivity, good biological specificity, suitable for automatic analysis and real-time detection. [0003] The detection of GMR biosensors is first to convert the changing biological signals in the s...

AI Technical Summary

Problems solved by technology

The traditional GMR biosensor detection system mostly adopts a current-type system detection scheme, which has a large scale and a long detection time, and because the output current of the biosensor is on the order of nA~uA, it is easily interfered by external factors such as the environment and the detection system. Cause detection accuracy to drop

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