4 Replies Latest reply on Jul 29, 2012 4:49 PM by user_14586677

    WaveDAC8

    pkx

      Where do I find the WaveDAC8 component and how do I install it into the concept librayr?

         

      Why was it not installed with 2.1?

        • 1. Re: WaveDAC8
          user_1377889

          Have a look here http://www.cypress.com/?rID=54769&cache=0 there is a video and an app-note.To install the wavedac follow the procedure in the app-note exactly.

             

           

             

          Bob

          • 2. Re: WaveDAC8
            user_14586677

            WaveDAC8 component not released in 2.1, one can speculate, like a number of

               

            other components, that work on its functionality not complete, so not an "official"

               

            module release yet for primetime.

               

             

               

            If you want to "roll" your own, so's to speak, you simply fill a table with a periods

               

            worth of waveform samples, and DMA it to a VDAC. Thats easy, and you can

               

            fill the table with sine, cosine, ramp, tri, square, sin(x), sin(x)/x.....anything you

               

            wish.

               

             

               

            More sophisticated, is burst N cycles of waveform, with a programmable delay in between. Many

               

            of todays programmable waveforms can be built. Because of VDAC settling time you are limited to ~

               

            1 Mhz sample rate. If you use IDAC, its ~ 100 nS. So if sample table size is 20 samples, max freq for

               

            VDAC is 50 Khz.

               

             

               

            Some DDS reference material that might be of help -

               

             

               

            http://www.analog.com/en/content/glp_dds/fca.html?gclid=CP_4vrnqv7ECFYNx4AodAQ4A3w

               

             

               

            Go to their website, much more ref material.

               

             

               

            Regards, Dana.

            • 3. Re: WaveDAC8
              user_14586677

              One more set of comments on DDS waveform generation.

                 

               

                 

              1) Jitter is related to not only the clock, but other interrupt related processes. So if

                 

              you use a timer, to set sample rate, with an ISR, you need to be concerned with jitter

                 

              of clock, and ISR machine behaviour and priority.

                 

               

                 

              2) Table depth controls waveform "fidelity", reproduction, hence harmonic distortion.

                 

              There is at  least one paper, to the best of my limited knowledge, in IEEE archives, that

                 

              discusses this. Not public domain unless you are a member. I have used 32 entry sine

                 

              tables, and on a spectrum analyzer they are close to 40 db down on harmonics. Larger

                 

              table size diminishing returns/bit. As to be expected. I will go out on  a limb and state you

                 

              are not going to get 60 db perfromance in a PSOC solution. Unless lots of external filtering.

                 

               

                 

              3) PSOC limited to 8 bit DAC, unless you resort to other techniques, like bit dithering, PWM generation,

                 

              etc.. Translate even lower max frequency generation capabilities.

                 

               

                 

              http://www.cypress.com/?rID=51137

                 

               

                 

              Regards, Dana.

              • 4. Re: WaveDAC8
                user_14586677

                One correction, types of waveforms to generate, sin(x)/X should have been typed

                   

                Sinc(x)/x.

                   

                 

                   

                Regards, Dana.