Title :
A wide dynamic range and fast update rate integrated interface for capacitive sensors array
Author :
Zhang, Xu ; Liu, Ming ; Chen, Hong ; Zhang, Chun ; Wang, Zhihua
Author_Institution :
Inst. of Microelectron., Tsinghua Univ., Beijing, China
Abstract :
A low-power CMOS capacitance-to-digital converter for capacitive sensors array is presented. It consists of a 16-channel MUX, a front-end with wide dynamic range for capacitance-voltage conversion and a novel voltage-pulses convertor. This novel circuit charges the measured capacitor indirectly and converts it into a proportional voltage, and then produces a 16-bits pulses-formed single-line output with multi-steps quantization method. The circuit can operate under 1.2V to 3.6V voltage supply for single battery application. The maximum input is 350pF with 0.75ms/ch update rate and 90μA power consumption when the operating clock is 100KHz. The chip has been design and fabricated in 0.18-μm 1P6M CMOS process with active area of 640×630μm2.
Keywords :
CMOS integrated circuits; capacitive sensors; capacitors; clocks; convertors; integrated circuit design; low-power electronics; radiofrequency integrated circuits; sensor arrays; 1P6M CMOS process; capacitance 350 pF; capacitance-voltage conversion; capacitive sensor array; capacitor measurement; channel MUX; clock operation; current 90 muA; frequency 100 kHz; integrated interface; low-power CMOS capacitance-to-digital converter; multistep quantization method; power consumption; pulses-formed single-line output; single battery application; size 0.18 mum; voltage 1.2 V to 3.6 V; voltage supply; voltage-pulses convertor; word length 16 bit; Arrays; Capacitance; Capacitive sensors; Capacitors; Clocks; Voltage measurement;
Conference_Titel :
Circuits and Systems (ISCAS), 2012 IEEE International Symposium on
Conference_Location :
Seoul
Print_ISBN :
978-1-4673-0218-0
DOI :
10.1109/ISCAS.2012.6271938
