A 106 dB A-Weighted DR Low-Power Continuous-Time &lt;inline-formula&gt; &lt;tex-math notation="LaTeX"&gt;$\Sigma \Delta $&lt;/tex-math&gt; &lt;/inline-formula&gt; Modulator for MEMS Microphones

Berti, Claudio; Malcovati, P.; Crespi, L.; Basçhirotto, A.

doi:10.1109/jssc.2016.2540811

Cited by 49 publications

(7 citation statements)

References 12 publications

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“…The requirement of always-on operation for keyword recognition demands new microphones with a reduced power consumption. As a consequence, switched-capacitor Sigma-Delta modulators have been improved using inverter-based opamp integrators [66], [67] or replaced by continuous time sigma-delta modulators [68]. However, both switched-capacitor and continuous time Sigma-Delta modulators still require an input buffer [69], [70] to couple the MEMS to the ADC.…”

Section: Linearization Of Open-loop Vco-adcs For Mems Microphones By ...mentioning

confidence: 99%

“…Given the oversampled nature of the Sigma-Delta modulator and the low signal level at the MEMS, this buffer is a critical block requiring high slew rate and very low noise, which results in a significant power consumption. On the other hand, continuous-time Sigma-Delta modulators [68] have a resistive input which also requires a voltage buffer to couple the MEMS high output impedance. Moreover, continuous-time Sigma-Delta modulators are sensitive to clock jitter, which demands special design techniques as for example, using a FIR DAC in the feedback [71].…”

Section: Linearization Of Open-loop Vco-adcs For Mems Microphones By ...mentioning

confidence: 99%

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A Novel Multi-Bit Sigma-Delta Modulator using an Integrating SAR Noise-Shaped Quantizer

Garvi

Prefasi

2018

2018 25th IEEE International Conference on Electronics, Circuits and Systems (ICECS)

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Section: Linearization Of Open-loop Vco-adcs For Mems Microphones By ...mentioning

confidence: 99%

Section: Linearization Of Open-loop Vco-adcs For Mems Microphones By ...mentioning

confidence: 99%

A Novel Multi-Bit Sigma-Delta Modulator using an Integrating SAR Noise-Shaped Quantizer

Garvi

Prefasi

2018

2018 25th IEEE International Conference on Electronics, Circuits and Systems (ICECS)

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“…The low bandwidth of the audio signals enables the design of interfaces for MEMS acoustic sensors, usually employing oversampled Sigma Delta (sans-serifΣΔ) data converters [10,11]. sans-serifΣΔ modulators based on a switched-capacitor (SC) technology have a larger power consumption in comparison with continuous-time (CT) sans-serifΣΔs, but with a more robust behavior against circuit impairments like modulator clock jitter [12].…”

Section: Introductionmentioning

confidence: 99%

“…Since the proposed VCO-ADC is mainly implemented with digital circuitry, it is a scalable solution in terms of area and power consumption, in contrast to SC-sans-serifΣΔ-based readout circuits for MEMS microphones. Furthermore, the SNR performance of this VCO-ADC implemented in a 130 nm CMOS process can compete with the SC-sans-serifΣΔ or the CT-sans-serifΣΔ performance [11,23].…”

Section: Introductionmentioning

confidence: 99%

A VCO-Based CMOS Readout Circuit for Capacitive MEMS Microphones

Quintero

Cardes

Pérez

et al. 2019

Sensors

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Microelectromechanical systems (MEMS) microphone sensors have significantly improved in the past years, while the readout electronic is mainly implemented using switched-capacitor technology. The development of new battery powered “always-on” applications increasingly requires a low power consumption. In this paper, we show a new readout circuit approach which is based on a mostly digital Sigma Delta (sans-serifΣΔ) analog-to-digital converter (ADC). The operating principle of the readout circuit consists of coupling the MEMS sensor to an impedance converter that modulates the frequency of a stacked-ring oscillator—a new voltage-controlled oscillator (VCO) circuit featuring a good trade-off between phase noise and power consumption. The frequency coded signal is then sampled and converted into a noise-shaped digital sequence by a time-to-digital converter (TDC). A time-efficient design methodology has been used to optimize the sensitivity of the oscillator combined with the phase noise induced by 1/f and thermal noise. The circuit has been prototyped in a 130 nm CMOS process and directly bonded to a standard MEMS microphone. The proposed VCO-based analog-to-digital converter (VCO-ADC) has been characterized electrically and acoustically. The peak signal-to-noise and distortion ratio (SNDR) obtained from measurements is 77.9 dB-A and the dynamic range (DR) is 100 dB-A. The current consumption is 750 μA at 1.8 V and the effective area is 0.12 mm2. This new readout circuit may represent an enabling advance for low-cost digital MEMS microphones.

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“…The amplitude of the testing signal. AES, IEC and EIAJ standards all use a −60 dBFS signal [3,4,15,16], and they are commonly used in [17,18]. But the amplitude is replaced by −40 dBFS in [19].…”

mentioning

confidence: 99%

An Audio Distortion Dynamic Range Index for Evaluating the Performance of Audio Systems

et al. 2020

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The dynamic range (DR) index lacking of an official definition leads to ambiguities in performance evaluation. The existing measurement methods of DR do not always match with the various actual application conditions, and some detailed distortion behavior of the device under test (DUT) is not extracted. In this paper, a new index for evaluating the DR performance of audio systems is proposed and validated, herein referred to as the audio distortion dynamic range (ADDR). It reduces the uncertainty of measurement conditions by an explicit definition and unifies the signal-to-noise ratio (SNR) and the signal-to-noise-and-distortion ratio (SINAD) indexes if under the same measurement condition. Moreover, to comprehensively reflect the impact of harmonic, spurious, and noise components on the DUT, the definitions of the traditional indexes based on classification of distorted components are replaced by the variable thresholds in the ADDR definition. Subsequently, the detailed steps of ADDR and the critical factors influencing its accuracy, are analyzed and then the optimized measurement conditions are given. Experiments based on simulated DUTs show the ADDR index can distinguish performance difference that the traditional indexes cannot distinguish, which proves it is an effective supplementary to the existing indexes in some real applications.

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A 106 dB A-Weighted DR Low-Power Continuous-Time <inline-formula> <tex-math notation="LaTeX">$\Sigma \Delta $</tex-math> </inline-formula> Modulator for MEMS Microphones

Cited by 49 publications

References 12 publications

A Novel Multi-Bit Sigma-Delta Modulator using an Integrating SAR Noise-Shaped Quantizer

A Novel Multi-Bit Sigma-Delta Modulator using an Integrating SAR Noise-Shaped Quantizer

A VCO-Based CMOS Readout Circuit for Capacitive MEMS Microphones

An Audio Distortion Dynamic Range Index for Evaluating the Performance of Audio Systems

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