Problem with noise in Sigma delta ADC

[bear7679]

Noise in Sigma delta ADC

I have designed a sigma-delta ADC. I tested the sample and found the snr of the ADC is only 70dB. I could not find where is wrong, who can help me?
Thank you!

 

[goodboy_pl]

Re: Noise in Sigma delta ADC

there could be several problems:
1. clocks are overlapping
2. the switches W/L is low (rds is high)
3. opamps alr slow

check them separately!!!

BEST!

 

[opamp741]

Re: Noise in Sigma delta ADC

I feel that ur integrator is getting saturated..
can u provide some more detail of ur design so that we can help u..
Regards

 

[kermit]

Re: Noise in Sigma delta ADC

Pls tell us more detail,such as your DSM structure !

 

[sanwolf]

Noise in Sigma delta ADC

analog DSM structure is more simple than others, i think your structure is all right. but some details in your design perhans is not good considered.