High-order sigma-delta closed-loop accelerometer interface circuit capable of self-checking harmonic distortion

Abstract

The invention relates to a high-order sigma-delta closed-loop accelerometer interface circuit capable of self-checking harmonic distortion, belongs to the field of MEMS (micro-electro-mechanical systems) inertial devices, and aims to solve the problem that the self-checking function of the existing accelerometer interface circuit mainly allows for self-checking on analog output accelerometer interface circuits and fails in self-checking on harmonic distortion for direct digital output closed-loop high-order sigma-delta accelerometer interface circuits. The high-order sigma-delta closed-loop accelerometer interface circuit capable of self-checking harmonic distortion comprises an accelerometer sensitive structure, a charge voltage converter, a preamplifier, a correlated double sampling and sample holding unit, a phase compensator, a self-checking unit, a primary integrator, a secondary integrator, a summation unit, a tertiary integrator, and a comparator. Operating states are selected through a switch of the self-checking unit. In the self-checking mode, the self-checking unit outputs equivalent acceleration signals to allow for self-checking. When external acceleration signals are checked, a mass block deviates from a balanced position and outputs charge signals to allow for checking on the external acceleration signals.

Description

technical field [0001] The invention is applicable to the field of MEMS inertial devices, and relates to a high-order Σ-Δ closed-loop accelerometer interface circuit with a harmonic distortion self-check function. Background technique [0002] Micromachined inertial sensors are the product of the combination of MEMS technology and inertial technology. Among all micromachined inertial sensors, micromachined accelerometers are one of the most widely used sensors in the market. Compared with traditional inertial devices, capacitive micromachined inertial sensors set The advantages of MEMS technology and IC technology are integrated to realize the high integration of inertial sensors. It has the advantages of small size, light weight, low cost, and mass production. It has broad application prospects in military and civilian fields. The micromachined accelerometer sensor is the core component of the miniature inertial measurement combination, which is widely used in automotive el...

AI Technical Summary

Problems solved by technology

[0005] The purpose of the present invention is to solve the self-testing function of the current accelerometer interface circuit, which mainly solves the self-testing of the accelerometer interface circuit of the analog output, but cannot realize the self-testing of the harmonic distortion of the closed-loop high-order Σ-Δ accelerometer interface circuit of the direct digital output problem, a high-order sigma-delta closed-loop accelerometer interface circuit with harmonic distortion self-test function is provided

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