Publications

@article{J20c,

title = {Large-amplitude Dithering Mitigates Glitches in Digital-to-analogue Converters},

author = {A. A. Eielsen and J. Leth and A. J. Fleming and A. G. Wills and B. Ninness},

url = {https://www.precisionmechatronicslab.com/wp-content/uploads/2020/06/J20c.pdf},

doi = {10.1109/TSP.2020.2978626},

issn = {19410476},

year  = {2020},

date = {2020-04-01},

journal = {IEEE Transactions on Signal Processing},

volume = {68},

pages = {1950-1963},

abstract = {Glitches introduce impulse-like disturbances which are not be readily attenuated by low-pass filtering. This article presents a model that describes the behaviour of glitches, and a method for mitigation based on a large-amplitude dither signal. Analytical and experimental results demonstrate that a dither signal with sufficient amplitude can mitigate the effect of glitches, when used in conjunction with a low-pass filter. The dither signal in conjunction with low-pass filtering essentially converts a glitch from a high-frequency to low-frequency disturbance.},

keywords = {DACs},

pubstate = {published},

tppubtype = {article}

}

@article{J17i,

title = {Existing Methods for Improving the Accuracy of Digital-to-Analog Converters},

author = {A. A. Eielsen and A. J. Fleming},

url = {https://www.precisionmechatronicslab.com/wp-content/uploads/2017/08/J17i.pdf},

doi = {10.1063/1.5000974},

year  = {2017},

date = {2017-10-01},

journal = {Review of Scientific Instruments},

volume = {88},

pages = {094702},

abstract = {The performance of digital-to-analog converters is principally limited by errors in the output voltage levels. Such errors are known as element mismatch and are quantified by the integral non-linearity. Element mismatch limits the achievable accuracy and resolution in high-precision applications as it causes gain and offset error, as well as harmonic distortion. In this article, five existing methods for mitigating the effects of element mismatch are compared: physical level calibration, dynamic element matching, noise-shaping with digital calibration, large periodic high-frequency dithering, and large stochastic high-pass dithering. These methods are suitable for improving accuracy when using digital-to-analog converters that use multiple discrete output levels to reconstruct time-varying signals. The methods improve linearity and therefore reduce harmonic distortion, and can be retrofitted to existing systems with minor hardware variations. The performance of each method is compared theoretically and confirmed by simulations and experiments. Experimental results demonstrate that three of the five methods provide significant improvements in the resolution and accuracy when applied to a general-purpose digital-to-analog converter. As such, these methods can directly improve performance in a wide range of applications including nanopositioning, metrology, and optics.},

keywords = {DACs},

pubstate = {published},

tppubtype = {article}

}

@article{J17c,

title = {Improving Digital-to-analog Converter Linearity by Large High-frequency Dithering},

author = {A. A. Eielsen and A. J. Fleming},

url = {https://www.precisionmechatronicslab.com/wp-content/uploads/2020/06/J17c.pdf},

doi = {10.1109/TCSI.2016.2561778},

issn = {1549-8328},

year  = {2017},

date = {2017-07-01},

journal = {IEEE Transactions on Circuits and Systems I},

volume = {64},

number = {6},

pages = {1409-1420},

abstract = {A new method for reducing harmonic distortion due to element mismatch in digital-to-analog converters is described. This is achieved by using a large high-frequency periodic dither. The reduction in non-linearity is due to the smoothing effect this dither has on the non-linearity, which is only dependent on the amplitude distribution function of the dither. Since the high-frequency dither is unwanted on the output on the digital-to-analog converter, the dither is removed by an output filter. The fundamental frequency component of the dither is attenuated by a passive notch filter and the remaining fundamental component and harmonic components are attenuated by the low-pass reconstruction filter. Two methods that further improve performance are also presented. By reproducing the dither on a second channel and subtracting it using a differential amplifier, additional dither attenuation is achieved; and by averaging several channels, the noise-floor of the output is improved. Experimental results demonstrate more than 10 dB improvement in the signal-to-noise-and-distortion ratio.},

keywords = {DACs},

pubstate = {published},

tppubtype = {article}

}