加速度计模拟输出的Σ-Δ压频转换新方法  

A New Method of Σ-Δ Voltage-to-Frequency Conversion for the Analog Outputs of Accelerometers

作　　者：刘晓为[1] 施长治[1] 谭晓昀[1] 

机构地区：[1]哈尔滨工业大学MEMS中心,黑龙江哈尔滨150001

出　　处：《测试技术学报》2008年第2期133-139,共7页Journal of Test and Measurement Technology

摘　　要：设计了一种基于Σ-Δ调制器技术的新型电压-频率转换器,用于将微加速度计的模拟电压信号转换为相应的频率输出信号.该电路采用中国电子科技集团24所的4μm P阱标准CMOS工艺参数进行模拟仿真.在10 V电源电压下,时钟频率为1.04 MHz,其输入电压范围为1.5 V^8.5 V,输出频率范围为40 kHz^533 kHz,转换灵敏度约为134 kHz/V,非线性度不大于0.08%.仿真结果证明,其对于恒定输入电压具有稳定的输出频率以及正负两种转换特性,因此可广泛应用于加速度计等矢量传感器的模数转换接口电路.A new voltage-to-frequency converter based on ∑-△ modulator technology is designed to convert the analog voltage signal to the corresponding frequency output in micro-accelerometer interfaces. The circuit is simulated with the Hspice parameters provided by the 24th Institute of Electronics of China and the layout design adopts its 4 μm P-well standard CMOS process parameters. The frequency of clock is 1.04 MHz, the input voltage range detected is from 1.5 V to 8.5 V and the frequency output range is from 40 kHz to 533 kHz under a 10 V power supply. The conversion sensitivity is about 134 kHz/V, the nonlinearity is less than 0.08%. The simulation results show that the system can provide a stable output frequency for a constant input voltage. Furthermore, it has positive and negative conversion characteristics. So it can be applied to ADC interface circuits of vector sensors.

关 键 词：电压频率转换器 ∑-△调制器 高线性度 加速度计接口电路 

分 类 号：TN431.1[电子电信—微电子学与固体电子学]