WaveDAC8

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PatrickK_71
Employee
Employee
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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?

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Bob_Marlowe
Level 10
Level 10
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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

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ETRO_SSN583
Level 9
Level 9
250 likes received 100 sign-ins 5 likes given

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.

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ETRO_SSN583
Level 9
Level 9
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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.

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ETRO_SSN583
Level 9
Level 9
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One correction, types of waveforms to generate, sin(x)/X should have been typed

   

Sinc(x)/x.

   

 

   

Regards, Dana.

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