Re: [time-nuts] AD9913 programmable modulus DDS. was: Re: An (unknown?) nasty feature of the DDS principle for time nuts applications

2011-01-25 Thread Poul-Henning Kamp
In message <4d3f06ca.8020...@karlquist.com>, "Richard (Rick) Karlquist" writes: >What you need is the AD9913. It has a programmable modulus. >Now you're not stuck with 2^32. You can pick any convenient >value. Isn't it more like M/N applied to DDS, than a variable MODULUS ? As far as I know th

Re: [time-nuts] AD9913 programmable modulus DDS. was: Re: An (unknown?) nasty feature of the DDS principle for time nuts applications

2011-01-25 Thread Bruce Griffiths
Since the 9913 lacks a means of low pass filtering the DAC reference it may well suffer from significant AM noise sidebands. With a well designed sine to square converter as required when using it as part of an offset source like that outlined in Rick's paper (probably desirable to reduce the ph

[time-nuts] AD9913 programmable modulus DDS. was: Re: An (unknown?) nasty feature of the DDS principle for time nuts applications

2011-01-25 Thread Richard (Rick) Karlquist
What you need is the AD9913. It has a programmable modulus. Now you're not stuck with 2^32. You can pick any convenient value. Rick Karlquist N6RK On 1/25/2011 5:37 AM, Ulrich Bangert wrote: Gentlemen, the pros and cons of DDS chips and how to improve them have been discussed here from time