Rezaa
Junior Member level 2
We know that there are three situation of Sub-Adc for this title
State 1) Vin>+Vref/4
State 2) Vin<-Vref/4
State 3) -Vref/4<Vin<+Vref/4
Also using dynamic comparator is most common, I've design that too
Additionally, we know that if Vin+ - Vin- > Vref+ - Vref- (Vin+>+Vref/4 and Vin-<-Vref/4 subsequently) Vop of comparator is 1 and the other one is 0 and it'll be inverse vice versa.
I have two questions about this part and I'll present my other issues later, I would be appreciate if you answer my clear simple questions please.
First Question:
I think I can't make it work for the state 3 by only comparator because states 2 and 3 have similar results; Vop=0, Von=1. I've realized I may implement the function using two dynamic comparators. let me know if I'm wrong and tell me how to do that in details please.
Second Question:
When Vout+ and Vout- of S/H of first stage have common mode,we can add that common mode to the thresholds of comparators, is this a good way or we should use a common mode cancellation circuit, would you please describe the issue of common mode presence too.
State 1) Vin>+Vref/4
State 2) Vin<-Vref/4
State 3) -Vref/4<Vin<+Vref/4
Also using dynamic comparator is most common, I've design that too
Additionally, we know that if Vin+ - Vin- > Vref+ - Vref- (Vin+>+Vref/4 and Vin-<-Vref/4 subsequently) Vop of comparator is 1 and the other one is 0 and it'll be inverse vice versa.
I have two questions about this part and I'll present my other issues later, I would be appreciate if you answer my clear simple questions please.
First Question:
I think I can't make it work for the state 3 by only comparator because states 2 and 3 have similar results; Vop=0, Von=1. I've realized I may implement the function using two dynamic comparators. let me know if I'm wrong and tell me how to do that in details please.
Second Question:
When Vout+ and Vout- of S/H of first stage have common mode,we can add that common mode to the thresholds of comparators, is this a good way or we should use a common mode cancellation circuit, would you please describe the issue of common mode presence too.
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