The Designer's Guide Community Forum

The Designer's Guide Community Forum
https://designers-guide.org/forum/YaBB.pl
Modeling >> Behavioral Models >> Sigma Delta Modulator VHDL-AMS Behavioral Model
https://designers-guide.org/forum/YaBB.pl?num=1111806948

Message started by gsuarez on Mar 25^th, 2005, 7:15pm

Title: Sigma Delta Modulator VHDL-AMS Behavioral Model
Post by gsuarez on Mar 25^th, 2005, 7:15pm

Hi,

I already post a topic on the VHDL-AMS section, but I decide to post one here. I think there are great people in these forums so I'll try to take the most of it :). As I post before, I'm working with a behavioral model of a 2nd order sigma delta modulator in VHDL-AMS. I already simulated the ideal model and works ok. I start the non-ideal model and was able to simulate the first order sigma delta. The problem is when I try to simulate the 2nd order model. Basically is the same 1st order model but with an extra SC integrator with different integrating weights, but this becomes unstable. Any help or comments will be appreciated.

George

Title: Re: Sigma Delta Modulator VHDL-AMS Behavioral Mode
Post by shpongle on Jun 1^st, 2006, 2:55am

You have to adapt the loop coefficients and size for stability.
Matlab toolbox:
search for Schreier's sigma-delta toolbox
Search for presentations of F. Medeiro at www.imse.cnm.es and then ESD-MSD cluster

http://www.dice.ucl.ac.be/dice/Thesis/fulltext/Vancaillie.pdf for models