A Switched Capacitor-Based SAR ADC Employing a Passive Reference Charge Sharing and Charge Accumulation Technique

Polineni, Sreenivasulu; Bhat, M. S.; Rekha, S.

doi:10.1007/s00034-020-01437-3

Cited by 9 publications

(13 citation statements)

References 25 publications

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“…Where the charge injection is defned as the charge that exists between the source and drain terminals when the sample switch is turned of, and the clock feed through is defned as the charge injected due to the overlapping coupling capacitor between the gate and drain terminals. Consequently, it is preferable to implement the sample switch by using CMOS transmission gates [8,64,103] or the bootstrap switch in Figure 4 [2,5,6,11,17,22,24,31,34,45,53,58,63,65 Te variations in conductivity are reduced by utilizing the CMOS transmission gates, but the problem of input dependence still exists. Additionally, a large parasitic capacitor that limits the resolution of SAR appears.…”

Section: Sar Sample and Hold Circuitmentioning

confidence: 99%

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Successive Approximation Register Analog-to-Digital Converter (SAR ADC) for Biomedical Applications

Arafa

Ellaithy

Zekry

et al. 2023

Active and Passive Electronic Components

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This study presents a survey of the most promising reported SAR ADC designs for biomedical applications, stressing advantages, disadvantages, and limitations, and concludes with a quantitative comparison. Recent progress in the development of a single SAR ADC architecture is reviewed. In wearable and biosensor systems, a very small amount of total power must be devoured by portable batteries or energy-harvesting circuits in order to function correctly. During the past decade, implementation of the high energy efficiency of SAR ADC has become the most necessary. So, several different implementation schemes for the main components of the SAR ADC have been proposed. In this review study, the various circuit architectures have been explained, beginning with the sample and hold (S/H) switching circuits, the dynamic comparator, the internal digital-to-analog converter (DAC), and the SAR control logic. In order to achieve low power consumption, numerous different configurations of dynamic comparator circuits are revealed. At the end of this overview, the evolutions of DAC architecture in distinct biomedical applications today can make a tradeoff between resolution, speed, and linearity, which represent the challenges of a single SAR ADC. For high resolution, the dual split capacitive DAC (CDAC) array technique and hybrid capacitor technique can be used. Also, for ultralow power consumption, various voltage switching schemes are achieved to reduce the number of switches. These schemes can save switching energy and reduce capacitor array area with high linearity. Additionally, to increase the speed of the conversion process, a prediction-based ADC design is employed. Therefore, SAR ADC is considered the ideal solution for biomedical applications.

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Section: Sar Sample and Hold Circuitmentioning

confidence: 99%

“…In the SAR ADC for biomedical applications, the target design is to obtain power consumption of less than microwatts. So, the regular structure of the SAR sample and hold switch is the bootstrap circuit [63]. Te diferent circuit schemes are summarized in Table 1.…”

Section: Sar Sample and Hold Circuitmentioning

confidence: 99%

Successive Approximation Register Analog-to-Digital Converter (SAR ADC) for Biomedical Applications

Arafa

Ellaithy

Zekry

et al. 2023

Active and Passive Electronic Components

View full text Add to dashboard Cite

show abstract

“…The dynamic comparator has high input impedance, negligible static power consumption, rail-to-rail output swing, precise noise, and mismatch robustness, consequently, it's far pretty distinguished for SAR ADC in Ref. [1],Kasi Bandla, et.al, has reviewed that static power consumption is excessive in Dynamic Latch Comparator with Pre-Amplifier topology and consequently no longer most suitable for low power applications. However, the above-mentioned topology is ideal for correct evaluation the Charge Sharing Dynamic Latch Comparator (CSDLC) is used in order to have low energy.…”

Section: Literature Reviewmentioning

confidence: 99%

A Contemporary Survey on Low Power, High Speed Comparators for Bio-Medical Applications

Rajalakshmi

Rani

Anand

2021

Advances in Parallel Computing

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The analysis of biomedical signals performs an important role in figuring out numerous issues in clinical science. Also, the urge to track biomedical signals in fitness and well-being control is progressively growing with the multiplied occurrence of persistent sicknesses over the last decade. By nature, the most of the real-time signals are analog. Hence, an Analog to digital converter (ADC) is required to transform the signal. In ADC architecture, the comparator is the essential block that performs a vital role and consumes greater power in ADC design. Numerous architectures for comparators relate to biomedical programs are mentioned in recent days. In this paper, the exceptional latest techniques of comparator designs are discussed with their key capabilities in conjunction with pros and cons.

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“…Hence, a power-efficient and fully programmable resolution ADC can substantially reduce the size and cost of the WBSN. In [7][8][9][10][11][12][13][14][15][16], adaptive-resolution ADC architectures are presented for implantable sensors. In all these papers, SAR ADC is designed with binary-weighted capacitive DAC using different switching methods.…”

Section: Introductionmentioning

confidence: 99%

“…The switched‐capacitor integrator SAR ADC [7] is implemented using operational transconductance amplifier (OTA) with programmable unity gain bandwidth (UGB) and slew rate, dynamic comparator, capacitors, switches and control logic. The advantages of switched‐capacitor integrator based SAR ADC over conventional SAR ADC are summarized as follows: the number of unit capacitors used in the binary‐weighted DAC is exponentially proportional to the resolution ( N bits).…”

Section: Introductionmentioning

confidence: 99%

A fully differential switched‐capacitor integrator based programmable resolution hybrid ADC architecture for biomedical applications

Polineni

Rekha

Bhat

2021

IET Circuits, Devices & Syst

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A novel switched‐capacitor integrator based programmable resolution analog to digital converter (ADC) architecture is proposed. The proposed hybrid ADC architecture can be switched between successive approximation register (SAR) and delta‐sigma modulator (DSM) mode in 8‐bit to 15‐bit resolution. A mathematical relationship showing the effect of mismatch of capacitors on ADC linearity is derived. A fully differential folded cascode operational transconductance amplifier (OTA) operating in a weak inversion region is designed using gm/ID technique with programmable unity gain bandwidth and slew rate. The designed OTA offers 83 dB DC gain. The proposed ADC, designed and laid out in UMC 180 nm standard CMOS technology, occupies an area of 0.228 mm2. The ADC resolution is programmable from 8‐bit to 15‐bit using a 3‐bit control bus (res[2 : 0]). The hybrid ADC operates in SAR mode from 8‐bit to 11‐bit resolutions and as the first‐order DSM with a multi‐bit quantizer in 12‐bit to 15‐bit resolutions. The dynamic performance of the proposed ADC is verified through post‐layout simulations with a supply voltage of 1.8 V. It exhibits a signal‐to‐noise and distortion ratio of 45–86 dB and consumes a power of 0.86–98 μW across target resolutions (8–15 bits).

show abstract

A Switched Capacitor-Based SAR ADC Employing a Passive Reference Charge Sharing and Charge Accumulation Technique

Cited by 9 publications

References 25 publications

Successive Approximation Register Analog-to-Digital Converter (SAR ADC) for Biomedical Applications

Successive Approximation Register Analog-to-Digital Converter (SAR ADC) for Biomedical Applications

A Contemporary Survey on Low Power, High Speed Comparators for Bio-Medical Applications

A fully differential switched‐capacitor integrator based programmable resolution hybrid ADC architecture for biomedical applications

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