Приборы и методы измерений запылённости окружающей воздушной среды. Краткий обзор

The main characteristics of airborne micro/nanoparticles, their impact on human health and air quality standards are presented. International standards classify microparticles by size (PM10, PM2.5, PM1, UFP), establish maximum allowable concentrations and control methods. Particular attention is paid to carbonand virus-containing microparticles control. To monitor the air environment in enclosed spaces and in transport, the portable sensors of micro-, nanoparticles are required with the ability to classify them by size and electrophysical characteristics.Detection of microparticles includes the sorting of particles entering the sensor by size and material type, subsequent actual detection of particles of the same kind, with subsequent classification by size, electrical and morphological characteristics. Separation of nanoand microparticles by size before detection improves the sensitivity and selectivity of the detector both in size and material. The virtual impactor and dielectrophoresis method are considered for integration in a Lab-on-Chip type sensor. Detection of microparticles is performed by separating the dispersed phase from the aerosol followed by the analysis, or directly in the air flow. The classification of detection methods according to speed and functionality is given. Among the methods allowing detection of micrometer and submicrometer size particles, the most suitable for miniaturization and serial production of Lab-on-Chip sensors are the multi-wavelength photoelectric, MEMS, and capacitor elements.The microelectromechanics, microfluidics and microoptics technologies make it possible to create portable sensor systems of the Lab-on-Chip type to detect particulates matter of micrometer and submicrometer size. A micro-, nanoparticles detector prototype based on alumina technology using MEMS elements for a compact Lab-on-Chip type sensor is presented. The proposed design for multifunctional portable detector of airborne micro/nanoparticles is prospective for industry, transport, medicine, public and residential buildings applications.Представлены основные характеристики переносимых воздухом микро/наночастиц, их влияние на здоровье человека и нормативы качества воздушной среды. Международные стандарты классифицируют микрочастицы по размеру (PM10, PM2,5, PM1, UFP), определяют предельно допустимые концентрации и методики их контроля. Особое внимание уделяется контролю углероди вируссодержащих микрочастиц. Для мониторинга воздушной среды в закрытых помещениях, в транспорте требуются портативные датчики микро-, наночастиц с возможностями их классификации по размеру и электрофизическим характеристикам.Детектирование микрочастиц включает сортировку попадающих в детектор микро/наночастиц по размеру и типу материала и собственно детектирование однотипных частиц с последующей классификацией по размеру, электрофизическим и морфологическим характеристикам. Разделение нано и микрочастиц по размеру перед детектированием повышает чувствительность и селективность детектора как по размерам, так и по материалу. Для интеграции в сенсоре Lab-on-Chip типа рассмотрены методы виртуального импактора и диэлектрофореза. Детектирование микрочастиц осуществляется с выделением дисперсной фазы из аэрозоля с последующим анализом либо непосредственно в воздушном потоке. Приведена классификация методов детектирования по быстродействию и функциональным возможностям. Среди методов детектирования частиц микронных и субмикронных размеров наиболее пригодны для миниатюризации и серийного изготовления Lab-on-Chip сенсоров мультиволновые фотоэлектрические, МЭМС, конденсаторные элементы.Технологии микроэлектромеханики, микрофлюидики и микрооптики позволяют создавать портативные сенсорные системы типа Lab-on-Chip для детектирования твёрдых частиц микронного и субмикронного размера. Представлен прототип детектора микро-, наночастиц на основе алюмооксидной технологии с использованием МЭМС элементов для компактного сенсора Lab-on-Сhip типа. Предлагаемая конструкция многофункционального портативного детектора микро/наночастиц воздушной (газовой) среды перспективна для применения в промышленности, транспорте, медицине, общественных и жилых помещениях

Sub-Femto-Farad Resolution Electronic Interfaces for Integrated Capacitive Sensors: A Review

Capacitance detection is a universal transduction mechanism used in a wide variety of sensors and applications. It requires an electronic front-end converting the capacitance variation into another more convenient physical variable, ultimately determining the performance of the whole sensor. In this paper we present a comprehensive review of the different signal conditioning front-end topologies targeted in particular at sub-femtofarad resolution. Main design equations and analysis of the limits due to noise are reported in order to provide the designer with guidelines for choosing the most suitable topology according to the main design specifications, namely energy consumption, area occupation, measuring time and resolution. A data-driven comparison of the different solutions in literature is also carried out revealing that resolution, measuring time, area occupation and energy/conversion lower than 100 aF, 1 ms 0.1 mm2, and 100 pJ/conv. can be obtained by capacitance to digital topologies, which therefore allow to get the best compromise among all design specifications

캐패시터 미스매치 분석에 기반한 12-bit 1 MSps SAR ADC 설계

학위논문 (석사)-- 서울대학교 대학원 : 공과대학 전기·정보공학부, 2019. 2. 김수환.본 논문에서는 캐패시터 미스매치가 successive approximation register (SAR) analog-to-digital converter (ADC)에 미치는 영향을 분석하고 이를 기반으로 설계한 캐패시터 digital-to-analog converter (DAC)으로 구현된 SAR ADC를 제안한다. 캐패시터 미스매치는 캐패시터 면적의 제곱근에 반비례한다. 따라서 캐패시터 미스매치를 줄이기 위해서는 캐패시터 면적을 늘려야하고 이는 전력 소모를 증가시킨다. 이 때문에 캐패시터 DAC의 크기를 결정하는 것은 SAR ADC의 설계에 있어 매우 중요하며 분석을 통해 최적화된 값을 찾는 것이 중요하다. 본 논문에서는 캐패시터 DAC의 각 캐패시터들의 미스매치로 인한 differential non-linearity (DNL)이 보다 작아지는 최소 캐패시터의 크기를 계산하였으며 이를 기반으로 스플릿 캐패시터 DAC과 더블 스플릿 캐패시터 DAC의 미스매치를 분석하였다. 본 논문은 미스매치 분석을 기반으로 미스매치 성능이 좋지 않은 캐패시터들의 크기를 키워 최적화한 캐패시터 DAC을 제안한다. 브릿지 캐패시터로 인한 선형성 저하를 막기 위해 브릿지 캐패시터 calibration 회로를 추가하였으며, 제안된 캐패시터 DAC의 성능이 기존의 스플릿 캐패시터 DAC의 성능과 비교하였을 때, 향상되었음을 monte carlo 모의실험 결과를 통해 증명하였다. 제안된 1MHz 12-bit SAR ADC 회로는 0.18 µm CMOS 공정에서 구현되었으며, 기준 전압을 내부에서 직접 생성하였다. Nyquist 입력을 주입하였을 때, 11.31 effective number of bits (ENOB)의 결과를 모의실험을 통해 얻었으며 4.6 V의 아날로그 공급 전압과 1.8 V의 디지털 공급전압에서 1.14 mW의 전력을 소모한다.This paper analyzes the impact of capacitor mismatch on successive approximation register analog-to-digital converter and proposes SAR ADC with capacitor digital-to-analog converter based on analysis of capacitor mismatch. The capacitor mismatch is inversely proportional to the square root of the capacitor area. In order to reduce the capacitor mismatch, the capacitor area must be increased, which increases the power consumption. Therefore, determining the size of the capacitor DAC is very important for the SAR ADC design and it is important to find the optimized value through analysis. This paper calculates the minimum capacitor size that the DNL due to the mismatch of each capacitor in the capacitor DAC is less than . Based on mismatch calculation, this paper analyzes the mismatch of both the split capacitor DAC and the double split capacitor DAC. This paper proposes an optimized capacitor DAC based on mismatch analysis by improving the size of capacitors with poor mismatch performance. A bridge capacitor calibration circuit was added to prevent linearity degradation due to the bridge capacitor. Montecarlo simulation results show that the performance of the proposed capacitor DAC is improved when compared with that of the conventional split capacitor DAC. The proposed 1 MHz 12-bit SAR ADC circuit is implemented in a 0.18 µm CMOS process and the reference voltage is directly generated internally. When the Nyquist input is injected, the result of 11.31 ENOB is obtained through simulation and consumes 1.14 mW of power at an analog supply voltage of 4.6 V and a digital supply voltage of 1.8 V.제 1 장 서 론 1 제 1 절 연구의 배경 1 제 2 절 기본적인 SAR ADC의 동작 원리 4 제 2 장 캐패시터 DAC 8 제 1 절 캐패시터 DAC의 design issues 8 1. kT/C 잡음 8 2. 안정화 시간 10 3. 캐패시터 미스매치 11 제 2 절 스플릿 캐패시터 DAC 13 제 3 절 브릿지 캐패시터 미스매치 calibration 기법 16 1. 브릿지 캐패시터 미스매치 calibration 기법의 원리 16 2. 브릿지 캐패시터 미스매치 calibration 기법의 동작 설명 21 제 3 장 제안하는 캐패시터 DAC을 이용한 SAR ADC의 설계 24 제 1 절 캐패시터 DAC 미스매치 분석 24 1. 캐패시터 미스매치 계산 24 2. 스플릿 캐패시터 DAC의 미스매치 분석 26 3. 더블 스플릿 캐패시터 DAC의 미스매치 분석 27 제 2 절 제안하는 캐패시터 DAC 29 제 3 절 SAR ADC의 구현 31 제 4 장 Layout 및 모의실험 결과 36 제 1 절 Layout 36 제 2 절 모의실험 결과 37 제 5 장 결 론 43 참고문헌 44 Abstract 45Maste

미세 입자 검출을 위한 저잡음 광학 센서 인터페이스

학위논문 (박사)-- 서울대학교 대학원 : 공과대학 전기·정보공학부, 2018. 8. 김수환.In this study, I propose a low-noise sensor interface for optical particulate matter (PM) detectors. The particles are classified as particulate matter 10 (PM10) ( CONTENTS 4 LIST OF FIGURES 6 LIST OF TABLES 9 CHAPTER 1 INTRODUCTION 1 1.1 PARTICULATE MATTER 1 1.2 PARTICULATE MATTER DETECTOR 3 1.2.1 CAPACITIVE SENSORS 3 1.2.2 OPTICAL SENSORS 6 1.3 THESIS ORGANIZATION 11 CHAPTER 2 ARCHITECTURE AND DESIGN CONSIDERATIONS OF THE OPTICAL PARTICULATE MATTER DETECTOR 12 2.1 INTRODUCTION 12 2.2 ANALOG FRONT-END CIRCUIT 15 2.2.1 TRANSIMPEDANCE AMPLIFIER 15 2.2.2 DC OFFSET CALIBRATION 19 2.2.3 GAIN AND FILTER STAGES 23 2.2.4 ANALOG-TO-DIGITAL CONVERTER 25 2.2.5 AVERAGE POWER CONTROL 29 2.3 DIGITAL BACK-END LOGIC 31 CHAPTER 3 CIRCUIT IMPLEMENTATION OF THE PROPOSED OPTICAL PARTICULATE MATTER DETECTOR 34 3.1 SENSOR BLOCK DIAGRAM 34 3.2 ANALOG FRONT-END CIRCUIT 41 3.2.1 DC OFFSET CALIBRATION CIRCUIT 44 3.2.2 ON-CHIP TEMPERATURE SENSOR CIRCUIT 49 3.3 DIGITAL BACK-END LOGIC 52 3.4 POWER MANAGEMENT CIRCUIT 58 3.4.1 UNDERVOLTAGE-LOCKOUT CIRCUIT 58 3.4.2 BANDGAP REFERENCE 61 3.4.3 OSCILLATOR 62 CHAPTER 4 EXPERIMENTAL RESULTS 64 4.1 DIE MICROGRAPH AND MODULE 64 4.2 MEASUREMENT SETUP 67 4.3 MEASUREMENT RESULTS 69 CHAPTER 5 CONCLUSION 77 BIBLIOGRAPHY 79 한글 초록 82Docto

28.7 CMOS monolithic airborne-particulate-matter detector based on 32 capacitive sensors with a resolution of 65zF rms

The adverse impact on human health of the exposure to airborne particulate matter (PM) is well known [1]. Although optical and gravimetric instruments are available to detect PM, they lack portability, have poor potential for miniaturization, and are not low cost. Instead, a better spatio-temporal resolution in PM monitoring by means of portable networked sensors would allow significant enhancements in terms of modeling and prediction capabilities and elucidation of subtle toxicological pathways [2]