A Novel Closed-Loop Controlled Interface IC for Differential-Capacitive Sensor Systems
A closed-loop controlled interface IC on the principle of force-balance for differentialcapacitive sensor system is presented in this work. Signal buffer immune for the parasitic capacitors is introduced to reduce the signal attenuation. A novel PID compensation block is designed to enhance the stability of the system with extremely high gain for accuracy, which is realized with active feedback Op Amp different from that of the traditional fashions. The circuit is fabricated in the 4μm BiCMOS process with the active area of 2.06mm2 (excluding the pads) which is costefficient for industrial and commercial applications. The interface circuit operates at ±5V power supply and consumes 23mW of power. It provides typical analog output scale of 100mV/g with full scale of ±30g typically, and total noise of 2.5mgrms through the frequency range of DC-160Hz.
Differential-capacitive sensor Force-balance PID compensation Op amp with active feedback
Xiaozong Huang Wengang Huang Yingjun Zhong Zhengrong He
Analog IC Design Center, SISC, Chongqing, 400060, China
国际会议
上海
英文
1447-1449
2010-11-01（万方平台首次上网日期，不代表论文的发表时间）