Design of Continuous-Time Sigma-Delta Modulators with Sine-Shaped Feedback DACs

Anis Latiri , Hassan Aboushady (1) , Nicolas Beilleau (1)

1 CIAN - Circuits Intégrés Numériques et Analogiques

This work presents a general method to design continuous-time /spl Sigma//spl Delta/ modulators with sine-shaped feedback DACs. A discrete time to continuous time transformation technique is used to compute the continuous-time loop filter coefficients, taking into account the sinusoidal feedback. Examples of high order lowpass and bandpass continuous-time /spl Sigma//spl Delta/ modulators are given as an illustration for the proposed design method. A transistor level sine-shaped feedback DAC is also proposed and compared to a recent circuit design. Finally, the sensitivity of these circuits to clock jitter is studied and compared to the traditional rectangular feedback pulse.

Domaines: Informatique [cs]

Anis Latiri, Hassan Aboushady, Nicolas Beilleau. Design of Continuous-Time Sigma-Delta Modulators with Sine-Shaped Feedback DACs. ISCAS 2005 - IEEE International Symposium on Circuits and Systems, May 2005, Kobe, Japan. pp.3672-3675, ⟨10.1109/ISCAS.2005.1465426⟩. ⟨hal-01418352⟩