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AD9838/9833 phase accumulator to waveform conversion

Question asked by ttse007 on Oct 5, 2017
Latest reply on Oct 6, 2017 by musach

I am having some small issues understanding the waveform conversions. How is the phase accumulator value used to generate the respective waveforms? I am working with both the AD9833 and AD9838.

 

For triangle waveform, how does the phase accumulator value leads both ramp up and down at the DAC and is the period 2*pi?

 

The datasheet for the AD9838 (p. 21, fig. 23) and 9833 (p. 16, fig. 25) are different.

http://www.analog.com/media/en/technical-documentation/data-sheets/AD9838.pdf 

http://www.analog.com/media/en/technical-documentation/data-sheets/AD9833.pdf 

 

For the sin waveform, I understand there is a 12-bit sin LUT, is only a quarter of the waveform stored? Is the first and last value 2^12/2 or 2^12/2 - 1? This influences the square waveform also, since the MSB is used at the SBO?

 

Thanks.

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