摘要
数字闭环石英挠性加速度计系统主要由石英挠性加速度计表头和数字检测电路组成,其极限精度取决于差动电容检测电路的灵敏度。针对数字闭环石英挠性加速度计前端差动电容检测的需求,给出了一种基于电容桥的差动电容检测方法。利用数字电路产生高频方波进行单载波调制,同时利用交流电容桥结构对载波信号进行处理,并设计后续的差分放大电路对载波信号进一步处理最终实现对微弱差动电容变化的检测。经过实验验证,检测电路对电容的检测最终实现最小分辨率约为1.8 f F(对应加速度变化1μgn)。
The digital closed-loop quartz flex accelerometer system is mainly composed of a quartz flex accelerometer header and a digital detection circuit.Its limit precision depends on the sensitivity of the differential capacitance detection circuit.In order to meet the demand for differential capacitance detection in front end of digital closed-loop quartz flex accelerometer,a differential capacitance detection method based on capacitance bridge is presented.Using digital circuit to generate high frequency square wave for single carrier modulation.At the same time,the AC capacitor bridge structure is used to process the carrier signal.The following differential amplifier circuit is designed and the carrier signal is further processed.Finally,the change of weak differential capacitance is detected.The experimental verification shows that the minimum resolution of capacitance detection by the detection circuit is about 1.8 f F at last,corresponding to acceleration change of 1μgn.
作者
陈炳贤
宋来亮
张春熹
CHEN Bingxian;SONG Lailiang;ZHANG Chunxi(School of Instrument Science and Opto-electronics Engineering,Beihang University,Beijing 100191,China)
出处
《传感器与微系统》
CSCD
2019年第12期116-119,共4页
Transducer and Microsystem Technologies
关键词
差动电容检测
电容桥
检测电路
数字闭环
石英挠性加速度计
differential capacitance detection
capacitance bridge
detection circuit
digital closed-loop
quartz flex accelerometer
