MIT Libraries logoDSpace@MIT

MIT
View Item 
  • DSpace@MIT Home
  • MIT Libraries
  • MIT Theses
  • Doctoral Theses
  • View Item
  • DSpace@MIT Home
  • MIT Libraries
  • MIT Theses
  • Doctoral Theses
  • View Item
JavaScript is disabled for your browser. Some features of this site may not work without it.

Noise shaping techniques for analog and time to digital converters using voltage controlled oscillators

Author(s)
Straayer, Matthew A. Z. (Matthew Allen Zornig)
Thumbnail
DownloadFull printable version (32.43Mb)
Other Contributors
Massachusetts Institute of Technology. Dept. of Electrical Engineering and Computer Science.
Advisor
Michael H. Perrott.
Terms of use
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. http://dspace.mit.edu/handle/1721.1/7582
Metadata
Show full item record
Abstract
Advanced CMOS processes offer very fast switching speed and high transistor density that can be utilized to implement analog signal processing functions in interesting and unconventional ways, for example by leveraging time as a signal domain. In this context, voltage controlled ring oscillators are circuit elements that are not only very attractive due to their highly digital implementation which takes advantage of scaling, but also due to their ability to amplify or integrate conventional voltage signals into the time domain. In this work, we take advantage of voltage controlled oscillators to implement analog- and time-to-digital converters with first-order quantization and mismatch noise-shaping. To implement a time-to-digital converter (TDC) with noise-shaping, we present a oscillator that is enabled during the measurement of an input, and then disabled in between measurements. By holding the state of the oscillator in between samples, the quantization error is saved and transferred to the following sample, which can be seen as first-order noise-shaping in the frequency domain. In order to achieve good noise shaping performance, we also present key details of a multi-path oscillator topology that is able to reduce the effective delay per stage by a factor of 5 and accurately preserve the quantization error from measurement to measurement. An 11-bit, 50Msps prototype time-to-digital converter (TDC) using a multi-path gated ring oscillator with 6ps of delay per stage demonstrates over 20dB of ist-order noise shaping. At frequencies below 1MHz, the TDC error integrates to 80fsrms for a dynamic range of 95dB with no calibration of differential non-linearity required. The 157x258pm TDC is realized in 0.13ipm CMOS and operates from a 1.5V supply.
 
(cont.) The use of VCO-based quantization within continuous-time (CT) [Epsilon] [Delta] ADC structures is also explored, with a custom prototype in 0.13pm CMOS showing measured performance of 86/72dB SNR/SNDR with 10MHz bandwidth while consuming 40mW from a 1.2V supply and occupying an active area of 640pm X 660pm. A key element of the ADC structure is a 5-bit VCO-based quantizer clocked at 950 MHz which we show achieves first-order noise-shaping of its quantization noise. The quantizer structure allows the second order CT Epsilon] [Delta] ADC topology to achieve third order noise shaping, and direct connection of the VCO-based quantizer to the internal DACs of the ADC provides intrinsic dynamic element matching (DEM) of the DAC elements.
 
Description
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2008.
 
Includes bibliographical references (p. 175-181).
 
Date issued
2008
URI
http://hdl.handle.net/1721.1/44724
Department
Massachusetts Institute of Technology. Department of Electrical Engineering and Computer Science
Publisher
Massachusetts Institute of Technology
Keywords
Electrical Engineering and Computer Science.

Collections
  • Doctoral Theses

Browse

All of DSpaceCommunities & CollectionsBy Issue DateAuthorsTitlesSubjectsThis CollectionBy Issue DateAuthorsTitlesSubjects

My Account

Login

Statistics

OA StatisticsStatistics by CountryStatistics by Department
MIT Libraries
PrivacyPermissionsAccessibilityContact us
MIT
Content created by the MIT Libraries, CC BY-NC unless otherwise noted. Notify us about copyright concerns.