On-line digital correction of the harmonic distortion in analog-to-digital converters

Abstract

A digital calibration technique for the on-line (real-time) correction of the Integral Nonlinearity (INL) in any Analog-to-Digital Converter (ADC) has been presented in this paper. MATLAB simulations substantiating the technique achieved around 20 dB improvement on a modeled 12-bit ADC with an initial Spurious-Free Dynamic Range of 80 dBFS. As a bonus, this technique can also correct for the offset error. The price paid for these benefits is the inclusion of an identical extra ADC, and some additional DSP circuitry.