Journal ArticleDOI
Delta-sigma modulators using frequency-modulated intermediate values
TLDR
In this paper, the first integrator is extracted and implemented by a frequency modulator with the modulating signal as the input, and the result is a simple delta-sigma modulator, allowing straightforward multibit quantization.Abstract:
This paper describes a new first- and second-order delta-sigma modulator concept where the first integrator is extracted and implemented by a frequency modulator with the modulating signal as the input. The result is a simple delta-sigma modulator with no need for digital-to-analog converters, allowing straightforward multibit quantization. Without the frequency modulator, the circuit becomes a frequency-to-digital converter with delta-sigma noise shaping. An experimental first- and second-order modulator has been implemented in a 1.2-/spl mu/m standard digital CMOS process and the results confirm the theory. For the first-order modulator an input signal amplitude of 150 mV resulted in a signal-to-quantization noise ratio (SQNR) of /spl ap/115 dB at 2 MHz sampling frequency and signal bandwidth of 500 Hz.read more
Citations
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Journal ArticleDOI
A 0.013 ${\hbox {mm}}^{2}$ , 5 $\mu\hbox{W}$ , DC-Coupled Neural Signal Acquisition IC With 0.5 V Supply
TL;DR: An area-efficient neural signal-acquisition system that uses a digitally intensive architecture to reduce system area and enable operation from a 0.5 V supply, alleviating system-level complexity is presented.
Journal ArticleDOI
A 78 dB SNDR 87 mW 20 MHz Bandwidth Continuous-Time $\Delta\Sigma$ ADC With VCO-Based Integrator and Quantizer Implemented in 0.13 $\mu$ m CMOS
M. Park,M.H. Perrott +1 more
TL;DR: A key innovation is the explicit use of the oscillator's output phase to avoid the signal distortion that had severely limited the performance of earlier VCO-based ADCs, which had made use of its output frequency only.
Journal ArticleDOI
A Mostly-Digital Variable-Rate Continuous-Time Delta-Sigma Modulator ADC
Gerry Taylor,Ian Galton +1 more
TL;DR: This paper presents a reconfigurable continuous-time delta-sigma modulator for analog-to-digital conversion that consists mostly of digital circuitry that is a voltage-controlled ring oscillator based design with new digital background calibration and self-cancelling dither techniques applied to enhance performance.
Journal ArticleDOI
A 16-mW 78-dB SNDR 10-MHz BW CT $\Delta \Sigma$ ADC Using Residue-Cancelling VCO-Based Quantizer
Karthikeyan Reddy,Sachin Rao,Rajesh Inti,Brian Young,Amr Elshazly,Mrunmay Talegaonkar,Pavan Kumar Hanumolu +6 more
TL;DR: A continuous-time (CT) ΔΣ modulator using a VCO-based internal quantizer that incorporates a nonlinear VCO as the second stage in a two-stage residue canceling quantizer (RCQ) and mitigates the impact of its nonlinearity by spanning only a small region of the VCO's V-to-F nonlinear tuning curve.
Journal ArticleDOI
Delta–Sigma A/D Conversion Via Time-Mode Signal Processing
C.S. Taillefer,Gordon W. Roberts +1 more
TL;DR: Experimental results reveal that these devices can achieve 7-9-bit resolutions within 125-400-kHz bandwidths, while occupying areas smaller than 50 mum ×50 mum and consuming less than 800 muW.
References
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High-speed CMOS circuit technique
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Journal ArticleDOI
Delta-sigma modulation in fractional-N frequency synthesis
TL;DR: In this article, a delta-sigma (Delta-Sigma) modulation and fractional-N frequency division technique for indirect digital frequency synthesis using a phase-locked loop (PLL) is described.
Journal ArticleDOI
Oversampling A-to-D and D-to-A converters with multistage noise shaping modulators
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Journal ArticleDOI
An oversampling delta-sigma frequency discriminator
R.D. Beards,M.A. Copeland +1 more
TL;DR: A circuit technique for performing oversampled A/D conversion on the phase/frequency information of an angle modulated signal is presented and it is shown that the technique is equivalent to a classic delta-sigma data conversion with instantaneous frequency as the input variable.
Journal ArticleDOI
Analog-input digital phase-locked loops for precise frequency and phase demodulation
TL;DR: In this article, a new class of analog-input digital phase-locked loops (ADPLLs) is presented that are insensitive to the deleterious effects of quantization, and do not exhibit nonlinear behavior when implemented with practical DCO's.
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