發(fā)布時間：2018-01-10 11:21

  本文關鍵詞：基于無源RFID標簽的低功耗溫度傳感器設計　出處：《西安電子科技大學》2016年碩士論文　論文類型：學位論文

  更多相關文章： 無源RFID 溫度檢測 SAR ADC 低功耗

【摘要】：RFID技術經(jīng)過幾十年的發(fā)展,在各個領域得到越加廣泛的應用,如交通運輸、醫(yī)療、商業(yè)商品自動化等領域。溫度傳感器作為傳感器中非常重要的一類,通過其元件隨溫度變化的特性來對溫度進行檢測,并根據(jù)溫度不同實現(xiàn)對系統(tǒng)的控制,將溫度傳感器集成于RFID標簽芯片有著非常廣泛的應用前景。本文設計了一款應用于無源RFID標簽芯片上、可對環(huán)境溫度精確測量、同時具有低功耗特點的CMOS溫度傳感器。本文所設計的溫度傳感器主要包括溫度檢測模塊和溫度量化模塊。溫度檢測模塊包括感溫電路和帶隙基準,通過感溫元件得到與溫度成比例的電壓/電流和與溫度無關的參考電壓。論文對傳統(tǒng)CMOS工藝下PNP晶體管和工作在亞閾值區(qū)MOS管的溫度特性進行分析、對比,得到工作在亞閾值區(qū)的MOS管具有更低的功耗。利用工作在亞閾值區(qū)MOS管的柵極-源極電壓差?VGS與溫度成正比的特性,實現(xiàn)感溫電路和帶隙基準,具有更低功耗的優(yōu)勢;再針對與后級模數(shù)轉換器ADC的輸入范圍匹配度,本文專門設計了CTAT(與溫度成反比)電路,對感溫電路進行改進,將其感溫電壓的范圍從245.7mV提升到709.7mV。論文針對溫度檢測電路的功耗、精度、以及與后級ADC輸入范圍匹配度等方面,從系統(tǒng)到模塊進行協(xié)同改進與折中,設計得到使用的溫度檢測電路的最終結構。溫度量化模塊采用低功耗ADC,將溫度檢測模塊得到的感溫電壓轉換為數(shù)字信號,對ADC有低功耗、低采樣頻率、高分辨率的要求。本文設計了一個超低功耗10bits SAR ADC,通過對ADC中的電容陣列DAC及其開關時序進行分析和優(yōu)化,得到一種新型的低功耗單端開關電容陣列。本文設計的新型單端電容陣列的參考電壓VREF為0.5V,僅為傳統(tǒng)參考電壓的一半,功耗約為傳統(tǒng)單端開關的1/8。最終得到10bits SAR ADC的參考電壓為0.5V,輸入范圍為0V~1V,采樣頻率為10KS/s,SNR為57.66dB,SFDR為72.48dB,SNDR為57.19dB,有效位數(shù)ENOB為9.2bit,功耗為0.046μW,達到了設計指標。論文將溫度檢測模塊與溫度量化模塊整合,得到CMOS溫度傳感器的總體架構,通過對整體的溫度傳感器在SMIC 0.18μm CMOS工藝下進行仿真驗證,其溫度檢測的精度達到±0.3℃,總功耗為0.394μW,適用于無源RFID溫度檢測標簽芯片。
[Abstract]:After decades of development, RFID technology has been more and more widely used in various fields, such as transportation, medical treatment, commercial commercial automation and other fields. Temperature sensors as a very important category of sensors. According to the characteristic of the component changing with temperature, the temperature is detected, and the control of the system is realized according to the different temperature. The integration of temperature sensor into RFID tag chip has a wide application prospect. In this paper, we design a passive RFID tag chip, which can accurately measure the environment temperature. At the same time, the CMOS temperature sensor with low power consumption. The temperature sensor designed in this paper mainly includes temperature detection module and temperature quantification module. The temperature detection module includes temperature sensing circuit and bandgap reference. The temperature dependent voltage / current and temperature independent reference voltage are obtained by temperature sensing elements. In this paper, the temperature characteristics of PNP transistors and MOS transistors working in sub-threshold region in traditional CMOS process are divided. Analysis. By contrast, it is found that the MOS transistors operating in the sub-threshold region have lower power consumption. The gate-source voltage difference of the MOS transistors working in the sub-threshold region is used. The characteristic of VGS is proportional to temperature, which realizes the temperature sensing circuit and bandgap reference, and has the advantage of lower power consumption. According to the matching degree of the input range of the ADC, this paper specially designed the circuit of CTAT (inversely proportional to temperature) to improve the temperature sensing circuit. The range of temperature sensing voltage is raised from 245.7 MV to 709.7 MV. The paper aims at the power consumption, precision and matching degree with the input range of ADC. From the system to the module for collaborative improvement and compromise, the final structure of the temperature detection circuit is designed. The temperature quantization module uses low-power ADC. The temperature sensing voltage obtained by the temperature detection module is converted into digital signal, which has low power consumption and low sampling frequency for ADC. In this paper, an ultra-low power 10bits SAR ADCs is designed, and the capacitor array DAC and its switching timing in ADC are analyzed and optimized. A new type of low-power single-ended switched capacitor array is obtained. The reference voltage VREF of the new single-ended capacitor array designed in this paper is 0.5V, which is only half of the traditional reference voltage. The power consumption is about 1 / 8 of that of the traditional single-ended switch. Finally, the reference voltage of 10 bits SAR ADC is 0.5 V, the input range is 0 V / 1 V, and the sampling frequency is 10 KS / s. The SNR is 57.66 dBU SFDR, the SNDR is 57.19 dB, the effective ENOB is 9.2 bit, and the power consumption is 0.046 渭 W. The temperature detection module and the temperature quantification module are integrated to get the overall structure of CMOS temperature sensor. Through the simulation of the whole temperature sensor in SMIC 0.18 渭 m CMOS process, the precision of temperature detection is 鹵0.3 鈩，

本文編號：1405079