| Summary: | 碩士 === 國立嘉義大學 === 資訊工程學系研究所 === 102 === A CMOS wind speed to continuous-time sigma-delta modulator (CT-SDM) for wind speed monitoring applications. Being a general-purpose wind transducer, it can be combined with various wind sensors. Till now, wind issues related to fit requirements of real environment, which needs to process higher environmental dynamic range, quickly response to controllers or computers, and insensitivity to noise, have not been investigated yet. Another innovation is that the fan noise at low frequency band can be easily removed into high frequency band by following the characteristics of the proposed chip. Based upon the device parameters of 0.35 µm 2P4M CMOS technology with 3.0 V power supply, all the functions and performance of the proposed chip are successfully tested and proven through SPICE simulations and measurements. The measured wind speed ranges from 2.2 to 4 m/s, and its corresponding voltage range is from 0.5 to 3 V. The measured higher wind speed ranges from 4.1 to 8 m/s, after performing the conversion algorithm, its corresponding voltage range is changed into 0.9 to 3 V. The OSR is 80 and the bandwidth is 15 kHz, the peak SNDR of whole circuits could be achieved 74.6 dB. The chip area is 1.2 x 2.2 mm2. The wind speed is linearly by the corresponding SNDR. In other words, when the wind speed is higher, the corresponding SNDR is higher. Conversely, the wind speed is smaller, the corresponding SNDR is smaller. By observing the changes of SNDR to calculate the wind speed that achieve wind speed real-time monitoring.
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