Delta sigma data converters have found to be of greater interest for almost 40
years now. Continuous time implementation of these converters, especially for high
speed and low power applications has been very challenging. Here in this thesis we have
discussed Resistor Capacitor (RC) implementation of Chebyshev Type II high pass Noise
Transfer Function (NTF). RC implementation has its own advantages compared to that of
a Switched Capacitor (SC) circuit.
While SC implementation has the advantages of being discrete-time, no resistors
used, and improved stability control, RC implementation has the advantage of no
switches being used (other than the quantizer) and therefore a simpler circuit
implementation.
In this thesis the details of the design and analysis of a fourth order RC delta
sigma data converter will be given. The NTF is that of a fourth-order Chebyshev Type II
highpass filter, where the noise is high passed and removed using a low pass filter and the
signal remains constant across the low frequency band.
The circuit implementation consists of four RC integrators with gain stages that
are determined from the desired transfer function. The feedback loop includes of a
sample and hold circuit followed by a one-bit quantizer: these are the only nonlinear
elements in the circuit design.
The circuit design procedure will be given, starting with the desired NTF
characteristics, and yielding the required gain parameters for the four integrator circuit
architecture, obtained to implement the requiredH(s). MATLAB is used for easy
computation.
The circuit simulation, yielding the bit stream frequency spectrum and the signal
to noise ratio, will be based on Mentor Graphics Eldo SPICE simulations.
The overall performance achieves the equivalent of 11 bits. This is obtained from
a fourth order circuit, using RC implementation. / Thesis (M.S.)--Wichita State University, College of Engineering, Dept. of Electrical and Computer Engineering. / Includes bibliographical references (leaves 37-38) / "December 2006."
| Identifer | oai:union.ndltd.org:WICHITA/oai:soar.wichita.edu:10057/614 |
| Date | 12 1900 |
| Creators | Baig, Shams Javid |
| Contributors | Paarmann, Larry D. |
| Source Sets | Wichita State University |
| Language | en_US |
| Detected Language | English |
| Type | Thesis |
| Format | 629951 bytes, application/pdf |
| Rights | Copyright Shams Javid Baig, 2006. All rights reserved. |
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