From one problem to the next...

11/20/2017

So the current ADAU1966 boards I am playing with have a new issue I have discovered. The ADAU1966 generates it's own "common mode" voltage reference to bias all the outputs to 2.25V. Two of the DAC boards I have tested at 1.47V on the CM pins.

Something is wrong here, it may be the extra capacitance I have on the pin. The data sheet recommends 10uF and 100nF. I have 100nf, 22uF (ceramic) and 220uF aluminium electrolytic. More is always better!!! Or not, in fact that is complete rubbish. I shall remove the 220uF and see what happens.

Extra PCB footprints are not an issue. It's all there to experiment with. If the changes are needed they are not really unexpected as with any project in development.

In any case, and I think I pointed this out in a previous post, the ADAU1966 seems to be hard to get now. The newer ADAU1966A is twice the price and just as hard to find in stock. Even so it is still a good DAC. I am working on a revised PCB layout, it would be good to make sure all designs (new and old) and up to their best performance and working 100%

2 Comments

Elvis

11/30/2017 06:42:30 am

Hello and congratulations for your blog.
Your project is very interesting I am not an electronics engineer, but I am a developer and I am interested in starting in the world of DSP.
Where can I start? What hardware do I need?

OHDSP

11/30/2017 02:52:18 pm

Thanks for the comment. At the moment I am not selling or making any populated boards. I am also working on some new versions with bug fixes and other changes.

To use any current designs you would need to build up the boards once you have obtained them from any good cheap PCB manufacturer like DirtyPCB or elecrow.

When I am happy with the designs I may look at making boards if I can get enough interest. As this is a hobby project it is a bit slow going at times!

From one problem to the next...

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Paul Janicki

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