
SigmaDelta |
ptolemy.domains.ct.demo.SigmaDelta.SigmaDelta |
A demo of Sigma Delta quantization. The underlying model is a
micro-accelerometer which uses beam-gap capacitor to measure accelerations.
A second order CT subsystem is used to model the beam.
The voltage on the beam-gap capacitor is sampled every T seconds (much
faster than the required output of the digital signal), then filtered by
a lead compensator (FIR filter), and fed to an one-bit quantizer.
The outputs of the quantizer are converted to force and fed back to the
beams. The outputs are also counted and averaged every N*T seconds to
produce the digital output. In our example, the external acceleration
is a Sin wave.
Reference: Mark A. Lemkin, <I>"Micro Accelerometer Design with Digital
Feedback Control"</I>, doctoral dissertation, University of California,
Berkeley, Fall 1997
Author(s): Jie Liu
Version:$Id: SigmaDelta.doc.html,v 1.1 2006/02/22 18:41:22 mangal Exp $
Pt.Proposed Rating:Red (liuj)
Pt.Accepted Rating:Red (cxh)