5-Bit SAR-ADC

Thread Starter

Fredi

Joined Jan 28, 2021
11
hi E,
The control logic should be fine there is a problem with the cout. The signal there is false. It must be a stepped function not a simple rectangle function.

The part with the switches I tried in different executions.

I've chosen a +/-5V supply and Logic because the high and low level of the whole circuit should be the same.
That was an advice from my professor.

I fixed the problem in #18.

Thank you.

F
 

ericgibbs

Joined Jan 29, 2010
18,849
hi F,
I am sure if you were checking a circuit of this type, for someone, you would determine that the count was correct.

I have reduced the circuit to Two bits, note the Ain and Ain for C1 C2, voltage levels, it is obvious that the timing of your switches is incorrect, so use this LTS a s check circuit.

E
 

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Thread Starter

Fredi

Joined Jan 28, 2021
11
hi F,
I am sure if you were checking a circuit of this type, for someone, you would determine that the count was correct.

I have reduced the circuit to Two bits, note the Ain and Ain for C1 C2, voltage levels, it is obvious that the timing of your switches is incorrect, so use this LTS a s check circuit.

E
Forum.JPG
If the timing of the switches is not correct the logik have to be wrong. The logic gives the impules for the switches to open or close.

F
 

ericgibbs

Joined Jan 29, 2010
18,849
hi F,
Look at this plot,
It is the last stage that is causing the problem, it always outputs a 1V signal so the Cout from the Comp sees an FF conversion.
Note the correct increments in Vc for B0,1,2.
then a 1V at B3. [ I have checked and its always the last stage that goes to 1V.
E
 

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