適用於CMOS製程之溫度感測器設計與應用

Temperature Sensor Design and Application by Using CMOS Technology

游明義(Ming-Yi Yo)

指導教授 ： 鍾文耀

中原大學/工學院/電子工程研究所/碩士(2003年)

https://doi.org/10.6840/cycu200300753

摘要

自從離子感測場效電晶體(ISFET)發明至今，由於具有與CMOS製程相容之優點，已成功整合感測器及訊號處理電路於單晶片系統上。研究顯示，ISFET對於溫度具有極大之不穩定性，導致不正確之量測值。因此，發展各種使ISFET穩定之補償技術，仍為一熱門之研究課題。
本篇論文的主要目的在於探討溫度感測器之設計與應用，為了使爾後ISFET、溫度感測器及訊號處理電路整合於同一晶片，採取適用於CMOS製程實現之溫度感測器架構。文中所設計的電路方塊包含以臨界電壓截取器為架構之溫度感測器、溫度感測器讀出電路、以軌對軌運算放大器建構之橋式源極浮接輸出酸鹼檢測電路，並探討酸鹼感測計之溫度效應及提出溫度補償之方法。
實驗結果顯示，本論文所設計之溫度感測器讀出電路量測結果，其對溫度的感測度為20mV/℃，為配合ISFET之使用，限制其感測範圍在0℃~50℃，準確度±2.3℃。另外，軌對軌運算放大器於5V操作時，開迴路增益達95dB，偏移電壓約在6.4mV，共模輸入電壓範圍與電壓輸出擺幅可達到正負電源之範圍。利用所設計之運算放大器建構橋式源極浮接組態讀出電路，結合波蘭科學院所提供的Si3N4感測膜ISFET進行pH值量測，在pH2至pH12標準溶液中靈敏度達53mV/pH。
為了探討ISFET之溫度效應，利用ISFET之行為模型及所設計之溫度感測器進行溫度補償模擬，於pH7之酸鹼溶液中，未進行溫度補償及補償後，其溫度係數分別為0.9mV/℃及0.03mV/℃。

關鍵字

溫度補償 ； 離子感測場效電晶體 ； 溫度感測器 ； CMOS

並列摘要

Due to the advantage of compatible with CMOS technology, ISFET sensor integrated with signal processing on a monolith has been proved to work. Investigations have demonstrated that ISFET exist a large thermal instability, which leads to inaccuracy measurement. So to develop different compensation method on ISFETs, is already a hot research topic today.
The major objective of this thesis is to discuss the design and application of temperature sensor. In order to have the capability to integrate with ISFET and signal processing, the adopted scheme of the temperature sensor can be implemented with CMOS technology. The major circuits include threshold voltage extractor as temperature sensor, temperature sensor readout circuit, bridge-type floating source ISFET readout circuit. Further, the thermal effect of ISFET and compensation method is also present.
The measured result shows the sensitivity of the thermal sensor readout circuit is 20mV/℃. To co-operate with ISFET, the limitation temperature range between 0℃~50℃. The accuracy is ±2.3℃. Further, with a 5V power supply, the rail-to-rail operational amplifier presents a DC gain of 95dB, offset voltage of 6.4mV and rail-to-rail common-mode input voltage range and voltage output swing. Between standard buffer solutions of pH2 to pH12, the bridge-type floating source ISFET readout circuit base on rail-to-rail amplifier has a sensitivity of 53mV/pH.
In order to verify the thermal effect of ISFET, the simulation of the behavior model of ISFET and the proposed temperature sensor are presented. In the pH7 solution, the temperature coefficients before and after the compensation are 0.9mV/℃ and 0.03mV/℃ respectively.

並列關鍵字

ISFET ； temperature compensation ； temperature sensor ； CMOS

參考文獻

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