Title :
On the synthesis of cascaded continuous-time ΣΔ modulators
Author :
Ortmanns, Maurits ; Gerfers, Friedel ; Manoli, Yiannos
Author_Institution :
Inst. of Microelectron., Saarlandes Univ., Saarbrucken, Germany
Abstract :
This paper introduces a new method for synthesis of high-order cascaded continuous time ΣΔ-modulators. A simple discrete time to continuous time (DT/CT) equivalence applied previously only to single loop modulators is extended and employed in cascaded CT ΣΔ-modulators. The method converts the DT loop-filter to a CT counterpart working with the same digital cancellation logic. Here the synthesis of a 3rd order continuous time SOFO modulator is presented. Some nonidealities are analyzed, both analytically and by simulation
Keywords :
cascade networks; continuous time systems; integrated circuit design; mixed analogue-digital integrated circuits; modulators; sigma-delta modulation; cascaded continuous-time ΣΔ modulators; digital cancellation logic; discrete time loop filter; discrete time to continuous time equivalence; high-order ΣΔ-modulators; optimal synthesis; sigma-delta modulator synthesis; Analytical models; Circuit noise; Delta modulation; Filters; Frequency; Linearity; Logic design; Noise cancellation; Sampling methods; Topology;
Conference_Titel :
Circuits and Systems, 2001. ISCAS 2001. The 2001 IEEE International Symposium on
Conference_Location :
Sydney, NSW
Print_ISBN :
0-7803-6685-9
DOI :
10.1109/ISCAS.2001.922074