Adaptive analog-to-digital conversion using self-dithering in data acquisition systems

Sampling rate and resolution are two main competing interests in digital data acquisition systems design. High sampling rate data acquisition systems, usually based on flash converters, exhibits low-resolution, and high resolution systems, usually based on sigma-delta or dual-slope converters, are generally slow. However, a compromise can be obtained if digital signal processing techniques are used after analog-to-digital conversion. This paper presents a solution that can be used to optimize the performance of data acquisition systems based on analog-to-digital data acquisition boards. A dynamic self-adjusted sampling rate and dithering are proposed in order to improve the signal-to-noise relation and measurement accuracy. Simulation and experimental results are presented to evaluate the digitizing system performance gains when the proposed solution is applied.