Sensor signal amplifying and conditioning circuit

Abstract

The invention relates to a sensor signal amplifying and conditioning circuit which comprises an instrument amplifier, a same-phase scale amplifier and a voltage follower, wherein the input end of the instrument amplifier is connected with a differential input signal; the voltage follower inputs the reference voltage into the reference voltage end of the instrument amplifier; the output signal of the instrument amplifier is accessed to the same-phase input end of the same-phase scale amplifier; the reverse-phase input end of the same-phase scale amplifier is used as a gain adjusting end; and the output end of the same-phase scale amplifier is used as the output end of the whole sensor signal amplifying and conditioning circuit. The invention is used for amplifying the small differential signal sent by the sensor and converting the differential signal into the single-end signal output to the reference end. By arranging the external resistor, the invention can realize zero-point and gain adjustment, extend the application range, and complete the impedance matching through the voltage follower.

Description

technical field [0001] The invention relates to the field of integrated circuits, in particular to an integrated sensor signal amplification and conditioning circuit. Background technique [0002] The output signal of the sensor is generally relatively weak, and it needs to be amplified, filtered, and level adjusted by the front circuit to meet the requirements of the single-chip microcomputer for the input signal. Because instrumentation amplifiers can amplify very weak differential voltage signals and have high input impedance, they are widely used in strain gauge bridge interfaces for measuring pressure and temperature, thermocouple temperature detection, and various low-side and high-side currents checking. However, the gain resistor of the existing instrumentation amplifier is either set internally as a fixed value, and the gain cannot be adjusted flexibly, which has great limitations; difference, its temperature coefficient cannot have good consistency. Moreover, al...

AI Technical Summary

Problems solved by technology

However, the gain resistor of the existing instrumentation amplifier is either set internally as a fixed value, and the gain cannot be adjusted flexibly, which has great limitations; difference, its temperature coefficient cannot have good consistency

Moreover, although the existing instrumentation amplifier has a reference voltage input terminal to realize the zero point adjustment function, it cannot be directly realized by a simple circuit in the form of an external resistor divider.

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