[time-nuts] Aging 5065A ?

[Poul-Henning Kamp]

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Bob wrote:
> You could also say that with a longer accumulator, you get a closer approximation to a desired waveform. 

The width of the accumulator does improve the waveform, but only if you need a frequency between the
ones possible with the more narrow accumulator.

It goes without saying that the extra bits only have an effect if they are non-zero.

Mike write:
> I do not believe that is true. Only a longer D/A would result in a closer approximation to the desired waveform.

Adding non-linear bits to the DAC increases noise significantly, because it introduces a periodic effect.

This stuff is all easy to simulate with a computer.

Try simulating a 12 bit Dac and a 14 bit DAC where the LSB is only half the magnitude it should be.

If I were trying to build a high-res DDS, I would calibrate the sine-table to the specific DACs imperfections.

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