An ultra low power ADC for wireless micro-sensor applications

Autonomous micro-sensor nodes rely on low-power circuits to enable energy harvesting as a means of sustaining long-term, maintenance free operation. This work pursues the design of an ultra low-power analog-to-digital converter (ADC) whose sampling rate and resolution can be scaled to dynamically recover power savings. The proposed ADC has a sampling rate of 0-100 kS/s and a resolution of either 12 or 8 bits. The design is based on the successive approximation register architecture (SAR), which is suitable for scaleable, micro-power operation. Specifically, the number of active blocks has been minimized to allow efficient power-gating, which, in-turn, has been leveraged to implement scalability features. Several new techniques to improve the efficiency of the ADC have been developed and employed. Analog offset calibration in the regenerative latch is used, to improve the power-delay product of the comparator; pre-amplifier cascade optimization is performed with consideration to thermal noise limitations; weak-inversion biasing is employed in the active amplifiers; passive switch-capacitors are used to generate the auto-zero reference voltage such the CMRR of the ADC is maximized;

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

2005

Author dc:creator

• Verma, Naveen

Advisor dc:contributor.advisor

• Anantha P. Chandrakasan.

• 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/1721.1/34462

OAI identifier oai:identifier

oai:dspace.mit.edu:1721.1/34462