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Products => Test Equipment => Topic started by: splin on May 18, 2016, 03:15:49 pm

Title: AD9910 DDS module 420M 1MSPS highest output sampling frequency signal generator
Post by: splin on May 18, 2016, 03:15:49 pm
Anybody tried one of these or have any thoughts?

http://www.ebay.co.uk/itm/AD9910-DDS-module-420M-1MSPS-highest-output-sampling-frequency-signal-generator-/331826021269?hash=item4d425f4395:g:ft4AAOSwJQdXB5XF (http://www.ebay.co.uk/itm/AD9910-DDS-module-420M-1MSPS-highest-output-sampling-frequency-signal-generator-/331826021269?hash=item4d425f4395:g:ft4AAOSwJQdXB5XF)

At £46 its not expensive but there's b*gger all information in the listing about it.

Or what about these 2 channel AD9958 based generators at £54?

http://www.ebay.co.uk/itm/AD9958-200MHz-2-Channel-DDS-Signal-Generator-500MSPS-Update-AD9854-ADI-Software-/272234422837?hash=item3f626fa235:g:iZQAAOSw3mpXLAKL (http://www.ebay.co.uk/itm/AD9958-200MHz-2-Channel-DDS-Signal-Generator-500MSPS-Update-AD9854-ADI-Software-/272234422837?hash=item3f626fa235:g:iZQAAOSw3mpXLAKL)

Or perhaps the 4 channel AD9959 version for £59?

http://www.ebay.co.uk/itm/4-Channel-AD9959-200MHz-DDS-Signal-Generator-500MSPS-Update-AD9854-ADI-Software-/271718275185?hash=item3f43abd871:g:-MYAAOSwqu9VE6nQ (http://www.ebay.co.uk/itm/4-Channel-AD9959-200MHz-DDS-Signal-Generator-500MSPS-Update-AD9854-ADI-Software-/271718275185?hash=item3f43abd871:g:-MYAAOSwqu9VE6nQ)

None of them are expensive but cheap Chinese test gear (or pretty much anything else) often seem to have some surprising failings/shortcomings/"I just don't believe it" moments.

Does anyone know of any (relatively) low cost AD9914 based signal generators?
Title: Re: AD9910 DDS module 420M 1MSPS highest output sampling frequency signal generator
Post by: radar_macgyver on May 20, 2016, 05:57:42 am
This barely qualifies as test gear - more of a breakout board. Having said that, the AD9910 is a decent performer, except for near-carrier noise. There was a web page titled "AD9910 sideband noise" but it goes to a 404 now. Martein did some sleuthing and found that the reference voltage for the AD9910's DAC did not have a bypass pin that filtered the noise it produced. This translated, through the DAC, to an increased noise floor. Note that this is not phase noise, it is amplitude modulation of the DAC output by a noisy reference. It's a pity, because the AD9910 is otherwise a great chip. I used its cousin, the AD9957 to build an ARB.