Concurrent estimation of amplifier nonidealities and excess loop delay in continuous-time sigma-delta modulators

In this work, a method for the concurrent estimation of nonidealities in continuous-time sigma-delta modulators is presented. Several nonidealities can degrade the performance of a sigma-delta modulator, even up to instability of the entire circuit. However, if these nonidealities are known, it is possible to correct for most of them - either in the analog or digital domain. In the past, many techniques for corrections of errors in sigma-delta modulators have been presented. Although these works show good results, most are only able to work on a single or few nonidealities simultaneously. In this paper, a feasible approach for estimating several nonidealities in a joint fashion has been applied to estimate some of the most prominent errors in a continuous-time sigma-delta modulator.