差分电容电压转换电路噪声性能分析及测试  

Performance Analysis and Test of Noise in Differential Capacitance to Voltage Conversion Circuit

作　　者：张霞[1] 胡世昌[2] 朱辉杰[2] 

机构地区：[1]西安邮电学院电子信息工程学院,西安710100 [2]浙江大学信息与电子工程学系,杭州310027

出　　处：《传感技术学报》2011年第9期1301-1304,共4页Chinese Journal of Sensors and Actuators

摘　　要：本文对电容检测式加速度计系统中广泛采用的差分电容电压转换电路建立了电容电压转换电路的等效噪声模型,并对双运放集成电路芯片所构成的差分电容电压转换电路的本底噪声以及仪表放大器输出端的噪声进行了测试,将电容电压转换电路本底噪声中的差模噪声分量和共模噪声分量进行了分离。测试结果表明影响加速度计系统噪声性能的差模噪声分量占电容电压转换电路本底噪声的50%。This paper presents an equivalent noise model of differential capacitance to voltage conversion circuit which is widely used in capacitive sensing accelerometers.The noise floors of the capacitance to voltage conversion circuit realized by dual amplifiers（two in a package）and the instrumentation amplifier are measured.The common-mode noise and the difference-mode noise in the noise floor of the capacitance to voltage conversion circuit can be calculated.The test results show that the difference-mode noise,which would affect the resolution of the capacitive sensing accelerometer system,constitutes nearly half the noise floor of the capacitance to voltage conversion circuit.

关 键 词：差分电容电压转换电路 共模噪声 差模噪声 

分 类 号：TH824[机械工程—仪器科学与技术]