3 Replies Latest reply on Feb 21, 2013 9:07 PM by userc_40792

    Problem of the DELSIG OFFSET

              I am making a design for test of DELSIG-ADC, Basically it's working, Then I think how to get more precise resolution. Finally want to compensate the offset. But which radix of the offset? In actual ADC value? Or converted value to u/m/ V? I don't know, One reason is no offset value has not able to get. Even It seems has some offset value, But always these value are ZERO, Is it OK? Configuration: [ resolution: 20bit, rate: 10/sec, continuous conversion, input mode: single-end, buffer mode: rail-to-rail, range: 0-6*vref, Vref: 1.024v ] Regards, Happy ADC   
        • 1. Re: Problem of the DELSIG OFFSET
          DaKn_263916

          "Finally want to compensate the offset. But which radix of the offset? In actual ADC value?

             

          Or converted value to u/m/ V?"

             

           

             

          You can work in either, but working directly with ADC counts would eliminate math error contribution

             

          due to scale factors if you were to work in converted value.

             

           

             

          Not sure why you are getting 0 as ADC count for Vin = 0, you should see some offset.

             

           

             

          Regards, Dana.

          • 2. Re: Problem of the DELSIG OFFSET
                    Hi Dana-san, thank you. The radix is presumed as adc count, because commonly number is count, Each converted value is depend on what unit user is use. Anyway, i have all source code then check up, it described [ Parameters: int32 offset : Offset in counts ] OK, nonetheless offset is always zero, measured value was change when every i did zero-in procedure. (this design can do zero-in when Sw was pushed) Single-end mode and rail-to-rail drive that can't measure offset value when input is zero ? right? A question is still remain but it's not a deal, not to hurry. Thank you, Happy ADC!   
            • 3. Re: Problem of the DELSIG OFFSET
                      This article is useful, Analog Calibration : http://www.cypress.com/?app=forum&id=2232&rID=72258