A Multibit Dual-Feedback CT \Delta\Sigma Modulator With Lowpass Signal Transfer Function

This paper presents a dual-feedback continuous-time delta-sigma modulator that features a signal transfer function with low sensitivity to coefficient variations. The anti-aliasing of this topology is similar to that of the feedback architecture while using only two feedback paths for modulators of...

Full description

Saved in:
Bibliographic Details
Published inIEEE transactions on circuits and systems. I, Regular papers Vol. 58; no. 9; pp. 2083 - 2095
Main Authors Ranjbar, M., Oliaei, O.
Format Journal Article
LanguageEnglish
Published IEEE 01.09.2011
Subjects
Analog to digital converter
anti-aliasing
continuous-time
delta-sigma modulation
Equations
Feedforward neural networks
Frequency modulation
Gain
low-pass filter
Topology
Transfer functions
Online AccessGet full text

Cover

More Information
Summary:This paper presents a dual-feedback continuous-time delta-sigma modulator that features a signal transfer function with low sensitivity to coefficient variations. The anti-aliasing of this topology is similar to that of the feedback architecture while using only two feedback paths for modulators of any order. The proposed architecture is a good candidate for low-power applications as it shows relaxed amplifier gain-bandwidth requirements for the first integrator. As a proof of concept, a third-order delta-sigma modulator has been implemented and tested which achieves 76 dB dynamic range over 5 MHz signal bandwidth while consuming 6 mW from a 1.2 V supply. The prototype chip, fabricated in a 130 nm CMOS process, provides 70 dB anti-aliasing with no out-of-band peaking in the signal transfer function.
ISSN:1549-8328
1558-0806
DOI:10.1109/TCSI.2011.2162464