使用電容比值調變電流技術實現之細胞移動感測器

Design of a Cell Migration Sensor with CRMC Front-End Circuit

彭崑悌(Kun-Ti Peng)

指導教授 ： 許孟烈

國立暨南國際大學/科技學院/電機工程學系/碩士(2012年)

https://doi.org/10.6837/NCNU.2012.00224

摘要

本論文提出了一個細胞移動感測器的晶片設計，感測器的前端電路使用電容比值調變電流(Capacitance-ratio-modulated Current, CRMC)技術實現，將感測到的電容轉換成正比於電容比值的電流，再透過雙斜率積分電路把調變好的電流轉換成脈衝寬度調變(Pulse-width-modulation, PWM)的形式輸出。為了節省功率，CRMC前端電路中的兩顆電晶體操作在次臨限區(Subthreshold Region)，晶片以TSMC 0.18 μm CMOS製程進行設計，感測電容範圍最大約7.5 fF，操作頻率75 KHz，消耗功率1.55μW，感測靈敏度為17.7 ns/fF。感測器將作成8x8的陣列，最後感測到的脈衝寬度調變訊號再透過計數器轉換成數位形式，晶片面積為600μm x 730μm，功率消耗119.9μW。

關鍵字

CRMC前端電路 ； 電容式細胞移動感測器

並列摘要

This thesis presents a cell migration sensor chip with capacitance-ratio-modulated current(CRMC) front-end circuit. The sensed capacitance is first transformed into a current proportional to a capacitance ratio by CRMC front-end circuit. Then this current is further transformed to pulse-width-modulation (PWM) output through a dual-slope integration circuit. To save power consumption, two MOSFETs of the CRMC circuit is bias in subthreshold region. A prototype chip with 8x8 sensor array is designed by using TSMC 0.18 μm CMOS process provided by CIC. Limited by the pixel size and the process, the maximum sensed capacitance is about 7.5 fF, and the sensitivity of the single CRMC circuit is 17.7 ns/fF. The chip also converts the sensed capacitance to 6-bit data through a PWM to digital circuit. The chip works at 75 kHz with a power consumption of about 119.9 μW, where the single CRMC consumes only 1.55μW.

並列關鍵字

CRMC Front-End Circuit ； Capacitive Cell Migration Sensor

參考文獻

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