An Improved Difference Temperature Compensation Method for MEMS Resonant Accelerometers.

Pengcheng Cai,Jiawei Wang,Xudong Zou,Kunfeng Wang,Xingyin Xiong

doi:10.3390/mi12091022

Abstract

Resonant accelerometers are promising because of their wide dynamic range and long-term stability. With quasi-digital frequency output, the outputs of resonant accelerometers are less vulnerable to the noise from circuits and ambience. Differential structure is usually adopted in a resonant accelerometer to achieve higher sensitivity to acceleration and to reduce common noise at the same time. Ideally, a resonant accelerometer is only sensitive to external acceleration. However, temperature has a great impact on resonant accelerometers, causing unexcepted frequency drift. In order to cancel out the frequency drift caused by temperature change, an improved temperature compensation method for differential vibrating accelerometers without additional temperature sensors is presented in this paper. Experiment results demonstrate that the temperature sensitivity of the prototype sensor is reduced from 43.16 ppm/°C to 0.83 ppm/°C within the temperature range of −10 °C to 70 °C using the proposed method.

Highlights

Microelectromechanical systems (MEMS) accelerometers have been widely used in many applications, such as mobile devices, gaming, automobile and healthcare [1,2] for its advantages of small volume, light weight, low power consumption and low cost [3]
Allan deviation during the temperaturecompensation ramp down. approach called proThis article proposed an improved temperature compensation approach called proportional difference for accelerometers based on differential frequency modulation
A paportional difference for accelerometers based on differential frequency modulation

Summary

Introduction

Microelectromechanical systems (MEMS) accelerometers have been widely used in many applications, such as mobile devices, gaming, automobile and healthcare [1,2] for its advantages of small volume, light weight, low power consumption and low cost [3]. Among various kinds of MEMS accelerometers, silicon resonant accelerometers are promising for high sensitivity, large linear range, low bias instability and so on [10,11,12,13]. A silicon resonant accelerometer converts external acceleration input into modulated frequency output as the acceleration will change the stiffness of resonator. The signal is easy to measure and not vulnerable to the circuit noise [14,15]. To reduce common noise and improve the sensitivity to external acceleration, differential structure is often adopted. The frequency of the resonator is only sensitive to the external acceleration. Salvia presented a real time temperature compensation for MEMS oscillators using an integrated oven, achieving a frequency stability of ±1 ppm from −20 ◦ C to

Methods

Discussion

Conclusion