[time-nuts] HP 5065A A1 replacement with DDS

Attila Kinali attila at kinali.ch
Sun Jun 24 17:34:35 EDT 2018

On Sun, 24 Jun 2018 14:05:52 -0700
Hal Murray <hmurray at megapathdsl.net> wrote:

> Does anybody have a handy formula for the spurs given the parameters for a DDS?

I think, you are looking for [1] and [2].

But please note, that both phase truncation and DAC non-linearity
spurs can be reduced by the right use of delta-sigma modulators,
which neither of the papers take into account (for obvious reasons).
For that, I suggest having a look at [3].

			Attila Kinali

[1] "How to Predict the Frequency and Magnitude of the Primary Phase
Truncation Spur in the Output Spectrum of a Direct Digital Synthesizer (DDS)",
AN-1396, 2016, by Ken Gentile, Analog Devices

[2] "Exact Analysis of DDS Spurs and SNR due to Phase Truncation and
Arbitrary Phase-to-Amplitude Errors", 2005, by Torosyan, Wilson,

[3] "Understanding Delta-Sigma Data Converters", 2017, by Pavan, Schreier, Temes

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