Systematic design method for LC bandpass /spl Sigma//spl Delta/ modulators with feedback FIRDACs

Author

Beilleau, Nicolas ; Kammoun, Abla ; Aboushady, Hassan

Author_Institution

Paris Univ.

fYear

2006

fDate

21-24 May 2006

Lastpage

1899

Abstract

In this paper, a generalized technique for the design automation of fs/4 bandpass SigmaDelta modulators using feedback FIRDACs is proposed. The FIRDACs are used to increase the degrees of freedom in order to perform an exact equivalence with high order discrete-time SigmaDelta modulators and also to allow a more efficient circuit implementation of the LC filter. The design technique is based on discrete time-continuous time equivalence simplified by using the method of partial fractions expansion. The excess loop delay is taken into account without making more difficult the calculations since we define how to get the orders of the FIRDACs. Several examples of design are simulated with different values of excess loop delay

Keywords

FIR filters; band-pass filters; digital-analogue conversion; discrete time filters; sigma-delta modulation; LC bandpass SigmaDelta modulators; discrete time-continuous time equivalence; excess loop delay; feedback FIRDAC; partial fractions expansion; Circuits; Delay effects; Design methodology; Digital modulation; Feedback; Finite impulse response filter; Frequency; Laboratories; Performance gain; Transfer functions;

fLanguage

English

Publisher

ieee

Conference_Titel

Circuits and Systems, 2006. ISCAS 2006. Proceedings. 2006 IEEE International Symposium on

Conference_Location

Island of Kos

Print_ISBN

0-7803-9389-9

Type

conf

DOI

10.1109/ISCAS.2006.1692980

Filename

1692980