A MEMS capacitive accelerometer interface circuit

Abstract

The embodiment of the invention relates to an MEMES capacitive acceleration meter interface circuit. The MEMS capacitive acceleration meter interface circuit comprises a sensitive unit and a reading-out device, wherein the reading-out device comprises a switch, a feedback capacitor, a front amplifier and a positive reference voltage and common-mode voltage generation circuit, the positive reference voltage and common-mode voltage generation circuit comprises a boost charge pump, a first low-noise linear voltage stabilizer and a second low-noise linear voltage stabilizer, the first low-noise linear voltage stabilizer and the boost charge pump form a positive reference voltage generation circuit, the second low-noise linear voltage stabilizer and the boost charge pump form a common-mode voltage generation circuit, the positive reference voltage generation circuit is used for generating a high voltage equivalent to two times of an input power voltage or above and converting the high voltage to a positive reference voltage equivalent to two times of the input power voltage, and the common-mode voltage generation circuit is used for generating a high voltage equivalent to two times of the input power voltage or above and converting a common-mode voltage equivalent to half of the input power voltage.

Description

technical field [0001] The invention relates to a capacitive inertial sensor, in particular to a micro-electromechanical system (Micro ElectroMechanical System, MEMS) capacitive accelerometer interface circuit. Background technique [0002] Capacitive inertial sensors generally include inertial sensors such as accelerometers and gyroscopes. These inertial sensors measure parameters such as the acceleration of the carrier relative to the ground in real time to determine the position of the carrier and the parameters of the earth's gravity field, and the measured changes translates into a change in capacitance. [0003] Taking MEMS capacitive accelerometers as an example, with the increasing maturity of MEMS technology, MEMS capacitive accelerometers are widely used due to their small size, high sensitivity, stable DC characteristics, small drift, low power consumption, and small temperature coefficient. However, the capacitance change of the MEMS capacitive accelerometer is ...

AI Technical Summary

Problems solved by technology

The performance of high-voltage devices used in high-voltage circuits is often not as good as that of low-voltage devices, which limits the performance of the entire system

At the same time, high input power means high power consumption. It is not suitable for long-term operation in geophysical exploration, inertial navigation and other applications that require battery power.

And reducing the voltage of the input power supply usually also reduces the positive and negative reference voltage value of the MEMS sensitive unit, which cannot provide enough feedback force in closed-loop applications

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