ON-LINE CALIBRATION AND DIGITAL CORRECTION OF MULTI-BIT SIGMA-DELTA MODULATORS
A. Fornasari, P. Malcovati, F. Maloberti
Abstract:
In this paper a novel method for the on-line calibration of the DAC used in multi-bit sigma-delta modulators is described. The proposed solution uses an additional trans- mission zero in the noise transfer function located at half of the sampling frequency. The mismatch between each unity element and a reference is properly modulated and located at the notch position. Since the notch frequency is noise free a simple digital processing allows us to measure mismatches and to store them in a digital memory for digital calibration purposes. The paper shows how to practically implement the above-described approach and discusses a convenient method to attain digital correction. Simulation results verify the proposed technique.
Keywords:
On-line Calibration, Sigma-delta
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IMEKO-IWADC-2003-13.pdf
DOI:
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