access icon free Compensation method of the excess loop delay in continuous-time delta-sigma analog-to-digital converters based on model matching approach

Continuous-time (CT) delta-sigma (Δ∑) analog-to-digital converters (ADCs) have one important constrain, namely the excess loop delay. Most excess loop delay compensation methods need to know the exact value of the excess loop delay in advance. However, the value of the excess loop delay is a uniformly distributed random variable. To improve system performance with the same loop filter, a new compensation algorithm for the excess loop delay of CT Δ∑ ADCs based on the model matching method is presented in this study. Compared with previous compensation methods, the model matching algorithm is more practical because the value of the excess loop delay varies randomly every clock period. It is shown through simulation that a mean value based algorithm can improve the SQNR performance of CT Δ∑ ADCs for the most probable values of the excess loop delay.

Inspec keywords: delta-sigma modulation; compensation

Other keywords: compensation method; uniformly distributed random variable; loop filter; continuous-time delta-sigma analog-digital converters; model matching approach; excess loop delay

Subjects: A/D and D/A convertors; A/D and D/A convertors

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