Systematic design of continuous-time ΣΔ modulator with VCO-based quantizer

Wagdy Gaber (1) , Mootaz Allam (1) , Hassan Aboushady (1) , Marie-Minerve Louërat (1) , El-Sayed Eid

1 CIAN - Circuits Intégrés Numériques et Analogiques

A methodology for the design of Continuous-Time (CT) Sigma-Delta (ΣΔ) modulators with VCO-based quantizer is proposed. The coefficients of the CT ΣΔ modulator are accurately calculated such that the noise transfer function of the modulator is exactly the same as a Discrete-Time (DT) ΣΔ modulator of the same order. The proposed design method takes into account loop-delay compensation as well as the shape of the feedback Digital-to-Analog Converter (DAC) signal. VCO non-idealities such as non-linear Kvco and phase noise are studied. Several design examples for different modulator orders and feedback DAC signal shapes are given to validate the proposed methodology.

Domaines: Electronique

Wagdy Gaber, Mootaz Allam, Hassan Aboushady, Marie-Minerve Louërat, El-Sayed Eid. Systematic design of continuous-time ΣΔ modulator with VCO-based quantizer. ISCAS 2010 - IEEE International Symposium on Circuits and Systems, May 2010, Paris, France. pp.29 - 32, ⟨10.1109/ISCAS.2010.5537115⟩. ⟨hal-00626955⟩