Dynamic Error Correction of a Digitizer for Time Domain Metrology

Published

February 1, 2003

Author(s)

David I. Bergman

Abstract

A method for numerical correction of distortion in a digitizer used for metrology applications is described. Investigation of the digitizer's error behavior in the phase plane leads to the development of an analytic error model that describes the digitizer's distortion behavior. Of particular significance is the model's ability to describe nonlinear error in the fundamental spectral component manifest as amplitude and frequency-dependent gain and phase error. When fitted only to the harmonic distortion content of the digitizer's output data, the model generates an amount of fundamental that correctly accounts for the error in the digitizer's gain that is not due to linear system response. The model is therefore able to improve not just the total harmonic distortion (THD) performance of the digitizer but its ac rms measurement accuracy as well. At 1MHz, the model linearizes the digitizer to 70mV/V over a range of 1 V to 8 V and reduces harmonic distortion by >20 dB. It is believed that this is the first time that results of this nature have been reported in the literature.

Citation

None

Pub Type

Journals

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Keywords

analog-to-digital converter, error model, phase plane, sine fit

Citation

Bergman, D. (2003), Dynamic Error Correction of a Digitizer for Time Domain Metrology, None, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=31305 (Accessed July 26, 2024)