Pipelined oversampling analog-to-digital converters

Oversampling and noise-shaping techniques, such as [delta sigma] modulation, are widely used in analog-to-digital conversion to achieve accuracy that exceeds that of integrated-circuit components. Such converters have an inherent tradeoff between accuracy and speed, whereby resolution in amplitude is achieved at the expense of resolution in time. Although much attention has been focused on improving the speed and power of [delta sigma] analog-to-digital converters, data rates remain limited to less than a few MHz and are not easily extended. A pipelined oversampling architecture is described that circumvents the speed-resolution tradeoff of conventional oversampling converters by performing spatial, rather than temporal, oversampling. It combines high-resolution capabilities of [delta sigma] techniques with the high speed of pipelined architectures so that both of these attributes are achievable. The architecture also differs from conventional oversampling in that it performs Nyquist-rate sampling. Power is improved as a result of a charge-domain implementation, reduced sensitivity to thermal noise, simplified decimation, and reduced circuit speed, which permits voltage scaling and use of low-power technologies. Circuit techniques for implementation of a pipelined oversampling converter are also presented. Although CCDs are not essential to the concept, such converters are most practically built using a combination of CCD and CMOS circuits. CCDs make analog pipelines with hundreds of stages feasible by providing fully-depleted operations which are highly accurate, low power, simple, and compact. Other operations are performed using nondepleted circuits.

Department dc:contributor.department

Massachusetts Institute of Technology. Dept. of Electrical Engineering and Computer Science.

Grantor dc:publisher

Massachusetts Institute of Technology

Year dc:date.issued

2003

Author dc:creator

• Paul, Susanne A. (Susanne Anita)

Advisor dc:contributor.advisor

• Hae-Seung Lee.

• Electrical Engineering and Computer Science.

Statement dc:rights

• M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission.

Licence dc:rights.uri

• http://dspace.mit.edu/handle/1721.1/7582

Language dc:language.iso

eng

Handle dc:identifier.uri

http://hdl.handle.net/1721.1/7981

OAI identifier oai:identifier

oai:dspace.mit.edu:1721.1/7981