Three-electrode micromechanical accelerometer digital close-loop control circuit and interface circuit thereof and three-electrode micromechanical accelerometer system

Abstract

The invention provides a three-electrode micromechanical accelerometer digital close-loop control circuit. The control circuit comprises a capacitance reading front-end circuit, a controller, a sigma-delta modulator, and a feedback voltage generator circuit which are connected in sequence, wherein the controller comprises an integrator. The integrator is used for enabling the output of a voltage signal, the low-frequency-range input of which is zero, to be non-zero. In addition, the invention further provides a three-electrode micromechanical accelerometer interface circuit and a three-electrode micromechanical accelerometer system, wherein the three-electrode micromechanical accelerometer interface circuit includes the digital close-loop control circuit.

Description

technical field [0001] The invention belongs to the field of MEMS inertial devices, and in particular relates to a three-electrode micro-mechanical accelerometer digital closed-loop control circuit and its interface circuit, and a three-electrode micro-mechanical accelerometer system. Background technique [0002] Micromachined accelerometers combine the technical advantages of MEMS technology and IC technology. They have the characteristics of small size, low power consumption, and low cost. They have great potential in both civilian and military applications, and have become research hotspots of research institutions or companies in various countries. Among them, the capacitive micro-accelerometer has gradually become the mainstream of micro-accelerometer research because of its low power consumption, high sensitivity, simple structure, and low temperature sensitivity. [0003] Accelerometers can work in open loop or closed loop. In the open-loop working state, the output...

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Problems solved by technology

However, the output of the system is still directly related to the displacement of the moving plate, which has a large nonlinearity and is very sensitive to the process deviation of sensitive structures and circuits.

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