A Capacitance to Digital Converter Using Continuous Time ΔΣ Modulator for Microphone-Based Auscultation

Narasimman, Neelakantan; Nag, Dipankar; Chai, Kevin Tshun Chuan; Kim, Tony Tae-Hyoung

doi:10.1109/jsen.2021.3067804

Cited by 9 publications

(9 citation statements)

References 18 publications

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“…Table 1 summarizes the performance of the proposed capacitive sensing system and compares it with other prototypes [15][16][17] and commercial products (Azoteq IQS211A/B and Microchip MTCH101). The proposed system adopts MAF, a digital low-pass filter, to enhance noise immunity without including ADCs that consume a lot of area and power.…”

Section: Measurement Resultsmentioning

confidence: 99%

“…Representing the detected situation with two different signals allows the system to interact with other digital parts without additional decoding steps, which is a great advantage of the proposed system. Table 1 summarizes the performance of the proposed capacitive sensing system and compares it with other prototypes [15][16][17] and commercial products (Azoteq IQS211A/B and Microchip MTCH101). The proposed system adopts MAF, a digital low-pass filter, to enhance noise immunity without including ADCs that consume a lot of area and power.…”

Section: Measurement Resultsmentioning

confidence: 99%

“…Apart from the C-T conversion technique, the C-V technique converts capacitance into analog voltages and then analog-to-digital converters (ADCs) convert the analog voltage into a digital signal [10][11][12][13][14][15]. However, the inclusion of an ADC increases the area and the power consumption of the entire system, which is a disadvantage of this approach despite intuitive operating principles.…”

Section: Introductionmentioning

confidence: 99%

“…However, the inclusion of an ADC increases the area and the power consumption of the entire system, which is a disadvantage of this approach despite intuitive operating principles. Other types of C-V conversion-based CDCs achieve high resolution using a delta-sigma modulator (DSM) [13][14][15]. However, the energy efficiency of DSM-based CDCs is limited due to the power-consuming OTA.…”

Section: Introductionmentioning

confidence: 99%

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Noise Immunity-Enhanced Capacitance Readout Circuit for Human Interaction Detection in Human Body Communication Systems

et al. 2022

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Recent healthcare systems based on human body communication (HBC) require human interaction sensors. Due to the conductive properties of the human body, capacitive sensors are most widely known and are applied to many electronic gadgets for communication. Capacitance fluctuations due to the fact of human interaction are typically converted to voltage levels using some analog circuits, and then analog-to-digital converters (ADCs) are used to convert analog voltages into digital codes for further processing. However, signals detected by human touch naturally contain large noise, and an active analog filter that consumes a lot of power is required. In addition, the inclusion of ADCs causes the system to use a large area and amount of power. The proposed structure adopts a digital-based moving average filter (MAF) that can effectively operate as a low-pass filter (LPF) instead of a large-area and high-power consumption analog filter. In addition, the proposed ∆C detection algorithm can distinguish between human interaction and object interaction. As a result, two individual digital signals of touch/release and movement can be generated, and the type and strength of the touch can be effectively expressed without the help of an ADC. The prototype chip of the proposed capacitive sensing circuit was fabricated with commercial 65 nm CMOS process technology, and its functionality was fully verified through testing and measurement. The prototype core occupies an active area of 0.0067 mm2, consumes 7.5 uW of power, and has a conversion time of 105 ms.

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Section: Measurement Resultsmentioning

confidence: 99%

Section: Measurement Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Noise Immunity-Enhanced Capacitance Readout Circuit for Human Interaction Detection in Human Body Communication Systems

et al. 2022

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“…In this sense, capacitance-to-digital converters (CDCs) represent a class of integrated interfaces capable of delivering a digital output readout of the capacitive sensor. Many architectures of CDCs are demonstrated in the literature, exploiting the principles of phase/pulse modulation (PM) [ 3 , 4 , 5 , 6 , 7 ],

modulation (

M) [ 8 , 9 , 10 ] and capacitive successive approximation register (CSAR) [ 11 , 12 , 13 , 14 , 15 ]. A detailed review of these techniques can be found in [ 16 ].…”

Section: Introductionmentioning

confidence: 99%

Design of a Capacitance-to-Digital Converter Based on Iterative Delay-Chain Discharge in 180 nm CMOS Technology

Cicalini

Piotto

Bruschi

et al. 2021

Sensors

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The design of advanced miniaturized ultra-low power interfaces for sensors is extremely important for energy-constrained monitoring applications, such as wearable, ingestible and implantable devices used in the health and medical field. Capacitive sensors, together with their correspondent digital-output readout interfaces, make no exception. Here, we analyse and design a capacitance-to-digital converter, based on the recently introduced iterative delay-chain discharge architecture, showing the circuit inner operating principles and the correspondent design trade-offs. A complete design case, implemented in a commercial 180 nm CMOS process, operating at 0.9 V supply for a 0–250 pF input capacitance range, is presented. The circuit, tested by means of detailed electrical simulations, shows ultra-low energy consumption (≤1.884 nJ/conversion), excellent linearity (linearity error 15.26 ppm), good robustness against process and temperature corners (conversion gain sensitivity to process corners variation of 114.0 ppm and maximum temperature sensitivity of 81.9 ppm/∘C in the −40 ∘C, +125 ∘C interval) and medium-low resolution of 10.3 effective number of bits, while using only 0.0192 mm2 of silicon area and employing 2.93 ms for a single conversion.

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A hybrid bioinspired model for improving the efficiency of correlative auscultation analysis

Singh,

Behera

2023

Int. j. inf. tecnol.

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A Capacitance to Digital Converter Using Continuous Time ΔΣ Modulator for Microphone-Based Auscultation

Cited by 9 publications

References 18 publications

Noise Immunity-Enhanced Capacitance Readout Circuit for Human Interaction Detection in Human Body Communication Systems

Noise Immunity-Enhanced Capacitance Readout Circuit for Human Interaction Detection in Human Body Communication Systems

Design of a Capacitance-to-Digital Converter Based on Iterative Delay-Chain Discharge in 180 nm CMOS Technology

A hybrid bioinspired model for improving the efficiency of correlative auscultation analysis

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