【摘要】 针对硅微谐振式压力传感器开环测试的需求,提出了一种基于稳态扫频的硅微谐振式压力传感器芯片测试方法,实现了高精度扫频激励信号电路与高分辨率检测电路的设计。此设计将单片机技术与直接数字频率合成技术的优点相结合,实现了范围为1 kHz～1 MHz精确扫频,其最小扫频步距为1 Hz。通过算法补偿有效减小了扫频激励信号的频率误差,使其平均绝对误差低于0.08 Hz。在幅值检测电路设计中,采用峰值检测电路与差分PulSAR ADC电路相结合,实现了传感器输出信号电压幅值的高分辨率检测,实测得到传感器幅频曲线,并对谐振器的谐振频率稳定性进行了测试,计算出了谐振器的机械品质因数和谐振频率等参数,为谐振器结构优化设计提供了依据。更多还原

【Abstract】 According to the requirements of the open-loop testing for the MEMS resonant pressure sensor,the chip testing method of the MEMS resonant pressure sensor based on the steady-state frequency sweep was presented,the designs of the high precision sweep excitation signal circuit and high resolution detection circuit were achieved.Through combining the advantages of the single chip microcomputer and direct digital frequency synthesis technology,the precise sweep with the range from 1 kHz to 1 MHz and the minimum sweep step of 1 Hz was realized.The frequency error of the sweep excitation signal was reduced through the corresponding compensation,and its mean absolute error was less than 0.08 Hz.In the design of amplitude detection circuits,through combining the peak detection circuit and differential PulSAR ADC circuit,the high resolution detection for the output signal voltage amplitude of the sensor was realized.The amplitude-frequency curve was obtained with the actual measurement,and the resonance frequency stability of the resonator was tested.The relevant parameters of the resonator were calculated,such as the mechanical quality factor and resonance frequency,providing the references for the resonator structure optimization design.更多还原