Sigma delta modulator - need explanation

[santi001]

sigma delta modulator

Hi,

I have a doubt about the modeling of sigma delta modulator.

I am very new to this field.

I got the delta sigma tool box from
https://www.mathworks.com/matlabcentral/fileexchange

For a second order modulator the ABCD state space model is given as
A=[1 0; 1 1];
B=[1 -1; 1 -2];
C=[0 1];
D=[0 0];
ABCD=[A B; C D];

Can anyone help me understand how these numbers came up.

 

[santi001]

Re: sigma delta modulator

Please someone clarify how the following equations are written.