ADC delsig functioning

[Anonymous]

Hello,

   

I am trying to use to the ADC Delsig component in PSoC 5. Vdda on the board is 3.3V. With the ADC Delsig I want to read voltage value in the range 0 - 3.3V. Delsig is configured to work 'single ended'.

   

Delsig  settings:

   

Conversion mode: multi sample (I have more than one voltage value to read)

   

Resolution (bits) : 17

   

Input range : 'Vssa to Vdda'

   

Reference (Vref) :'Internal Vdda / 3 (1.1V)' (only option available not considering the external bypass capacitor)

   

Gain : 1

   

Buffer mode : Rail to rail

   

I am testing the circuit imposing voltage value to the ADC (from 0 to 3.3 in steps of 0.1V). I can not see any variation in the ADC delsig output when input voltage value exceed about 2.1V. In addition I can not understand how to calculate LSB amplitude (V) in order to convert the delsig output  (digits) to V.

   

Actually I am using this formula :

   

LSB= (Vdda-Vssa)/2^resolution 

   

output_v = output_digit * LSB

   

There is something wrong because using this formula input step of 0.1 V results on an output step of about 0.15V.

   

Thank you.

[Bob_Marlowe]

It is easier for us to check your project when you post your complete project, so that we all can have a look at all of your settings. To do so, use
Creator->File->Create Workspace Bundle (minimal)
and attach the resulting file.

       

Bob

[Anonymous · Accepted solution]

        Solved. There were a bug in the hardware. Sorry for the disturb.   

[Bob_Marlowe]

Phew! Great, I thought I was at end of my wits!  😉

       

Bob