Circuit and method for regulating detecting end resonant frequency of capacitor type micro-electromechanical systems (MEMS) gyroscope

Abstract

The invention discloses a circuit for automatically regulating detecting end resonant frequency of a capacitor type micro-electromechanical systems (MEMS) gyroscope. The capacitor type MEMS gyroscope comprises a central mass block, a drive end and a detecting end, wherein the drive end comprises a drive end electrode, the detecting end comprises a detecting end electrode, and the detecting end electrode is provided with an input end for inputting a bias voltage (Vi) to form capacitance between the central mass block and the detecting end electrode. The circuit regulates the bias voltage (Vi) according to difference between output voltage signals of the drive end and the output voltage signals of the detecting end, and thus the detecting end resonant frequency is regulated. The detecting end resonant frequency of the capacitor type MEMS gyroscope van be regulated automatically and is enabled to conform to the frequency of the drive end signals, and mismatch caused by process allowance or changes of working environment is corrected.

Description

Technical field [0001] The invention relates to the field of MEMS and circuits, in particular to a circuit and method for automatically adjusting the resonance frequency of the detection end of a capacitive MEMS gyroscope based on phase detection. Background technique [0002] MEMS devices are based on silicon micromachining technology, and their outstanding features are small size, low power consumption, and easy integration. MEMS gyroscope is an angular velocity sensor based on MEMS technology that has emerged in recent years. Unlike traditional gyroscopes based on the principle of conservation of angular momentum, MEMS gyroscopes cannot make low-damping high-speed rotating parts on the substrate. Therefore, MEMS gyroscopes measure angular velocity mainly based on the Coriolis effect. figure 1 Is the schematic diagram of the MEMS gyroscope, such as figure 1 As shown, in a rotating reference system, the mass 11 moving in the radial direction (y direction in the figure) will be a...

AI Technical Summary

Problems solved by technology

[0009] What the present invention aims to solve is the problem that the resonant frequency of the detection end of the capacitive MEMS gyroscope is inconsistent with the frequency of the drive end due to factors such as changes in the process or working environment, thereby reducing the detection sensitivity. When there is a tolerance in the process or the temperature changes, the detection end The resonant frequency will be automatically adjusted to the frequency of the drive signal, so that the angular velocity detection sensitivity of the device can be kept at a good level

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