Sensor array readout circuit based on chopper technology

Abstract

The invention relates to a sensor array readout circuit based on a chopper technology. The sensor array readout circuit based on the chopper technology comprises a fully differential input stage. An input terminal of the fully differential input stage is connected with a signal modulation switch. An output terminal of the fully differential input stage is connected with a difference to single terminal signal switching stage through a signal demodulation switch. The difference to single terminal signal switching stage is connected with the output terminal of an output buffer stage through a first compensation capacitor. And the output terminal of the difference to single terminal signal switching stage is connected with a same-phase terminal of the output buffer stage. The same-phase terminal of the difference to single terminal signal switching stage is connected with the output terminal of the output buffer stage through a second compensation capacitor. An anti-phase terminal of the difference to single terminal signal switching stage is grounded through a third compensation capacitor and the anti-phase terminal of the output buffer stage is grounded. The circuit of the inventionhas a simple structure. An offset voltage and low frequency noises can be eliminated. An integration level of a system and a signal to noise ratio can be increased. A range of application is wide, safety and reliability can be achieved.

Description

technical field [0001] The invention relates to a readout circuit, in particular to a sensor array readout circuit based on chopper technology, which belongs to the technical field of weak signal detection. Background technique [0002] With the continuous improvement of the level of science and technology, the process technology of integrated circuits has been developed, which provides a guarantee for the microsystem in which the sensor and the readout circuit are integrated. With the continuous deepening of the application of micro-electro-mechanical systems in various fields of the country, people's performance requirements for micro-electro-mechanical systems are also getting higher and higher. It is specifically manifested in higher integration, higher signal-to-noise ratio, etc. [0003] For sensor signal detection, the first performance to consider is the signal-to-noise ratio of the sensor system. In the traditional sensor array detection system, capacitive transim...

AI Technical Summary

Problems solved by technology

The problem with this method is that the offset voltage of the sensor cannot be eliminated, and a correlated double sampling circuit (CDS) needs to be added behind the CTIA circuit.

[0005] However, conventional sensor readout circuits such as figure 1 In that way, the offset voltage cannot be eliminated directly, and a complex correlated double sampling circuit needs to be added

And as figure 2 In that way, although the readout circuit using the traditional chopping technology can eliminate the offset voltage and reduce the low frequency noise, because of the filter circuit, the speed of the circuit is limited and cannot be used in the sensor array readout circuit.

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