A Multichannel Oscillator for a Resonant Chemical Sensor System

作者：Lee Hyunjoo Jenny^*; Park Kwan Kyu; Oralkan Omer; Kupnik Mario; Khuri Yakub Butrus T

来源：IEEE Transactions on Industrial Electronics, 2014, 61(10): 5632-5640.

DOI：10.1109/TIE.2014.2300031

• Capacitive micromachined ultrasonic transducer (CMUT)
• chemical sensor
• humidity detection
• multichannel oscillators

Vapor detection using highly sensitive miniaturized resonant sensors is of great interest for many applications, including consumer, industrial, and environmental applications. An operational-amplifier-based multichannel oscillator that interfaces with a 50-MHz capacitive micromachined ultrasonic transducer array is presented for chemical sensing applications. The circuit was implemented in a 0.18-mu m CMOS technology to reduce power consumption, number of wires, and active area per channel. The presented integrated circuit also addresses the potential-frequency-locking problem between channels by allowing the open-loop gain to be adjustable off-chip. The feasibility of the developed oscillator for the chemical sensing application is demonstrated. Two channels that were operated simultaneously achieved excellent volume sensitivities of 8.5 x 10(-4)%/Hz and 3.9 x 10(-4)%/Hz, respectively, to relative humidity in N-2.

• 出版日期2014-10