I designed a 2nd order sigma-delda ADC in matlab.but I don't know why the power spectrum of noise is so bad.could someone point out the problems? I would appriciate any help.here is my code:
k=100; %oversampling rate
fs=200; %the nyquist frequence
t=0:1/(k*fs):1;
x=sin(2*pi*100*t);
v1(1)=0; %2nd order ADC
v2(1)=0;
u2(1)=-1;
y(1)=1;
for n=2:length(x)
v2=v2(n-1)+u2(n-1);
if v2>=0
y=1;
else y=-1;
end
e=y-v2(n-1);
u1=x-y;
v1=v1(n-1)+u1;
u2=v1-y;
end
thanks for your attention!
I have sovled the problem.
the amplitude of the source signal can't be 1, which equals to the Vref. that will lead to the unstable state.
but is that the rule of ADC?
thanks for your attention!
I have sovled the problem.
the amplitude of the source signal can't be 1, which equals to the Vref. that will lead to the unstable state.
but is that the rule of ADC?