Research on Chopper-Stabilized Operational Amplifier Design for Temperature-Sensing System.

• Main Authors: Ying-Neng Huang, 黃英能
• Other Authors: Tai-Ping Sun
• Format: Others
• Language: zh-TW
• Published: 2003
• Online Access: http://ndltd.ncl.edu.tw/handle/47531730271662058332

碩士 === 國立暨南國際大學 === 電機工程學系 === 91 === The aim of this thesis is to design and realize a non-contact temperature-sensing system by combining thermopile sensor, signal processing circuit as well as display module. Through the design, we learned how to deal with signal and noise for system considerations. The emphasis of this thesis is placed on the design of signal processing circuit including chopper-stabilized operational amplifier, rail-to-rail constant transconductance operational amplifier, and bandgap reference circuit. These circuits were implemented through the chip-implementation-center (CIC) using TSMC 0.35 um 1P4M standard CMOS process for full-custom design. An operational amplifier was designed as the pre-amplifier for amplifying the signal from the thermopile by using chopper-stabilized technique which significantly reduced the low-frequency noise, offset and temperature drift. Form our experimental results, the amplifier had a low noise of 0.87uVP-P at 0.1~10Hz, a offset of 16.4uV, and a temperature drift of 0.18uV/°C at chopping frequency of 5kHz with a resolution of 0.011°C. Besides, by using thermistor as a temperature-compensation device and found that the inaccuracy caused by the temperature-compensation circuit is less than ±0.1°C at ambient temperature of 10.5∼37°C. The supply voltage of the temperature-sensing system is 3V with a power consumption of 8.8mW. The temperature sensing range and operation range of the system is -126∼163°C and 10.5∼37°C, respectively. The inaccuracy is less than ±0.1°C when measured range is between 34∼47°C.