SparkFun Forums 

Where electronics enthusiasts find answers.

Have questions about a SparkFun product or board? This is the place to be.
By brusch
#192423
Hello,
your MiniGen board has some issues, which could be easily resolved.

(1) The oscillator is an 3,3V version, but if the board is used at 5V, the oscillator gets also 5V and becomes very hot.
(Somewhere I read this schould be fine, yes, it works for some time, but I have already killed a device this way...)
I would suggest: Use osci always at 3,3V, the AD9837 would accept MCLK-Input even if working at 5V.

(2) After some time, the AD8045 stopped working in an built-in device. I don't know why, VCC was stabilized externally at 5V.
Maybe there was an thermal issue from the osci...
(I really don't understand why this OPV is used at all. I understand the functionality, but I don't see the need.)
However, if you love the filter, keep it.
But it would be a really good idea to make the output of the AD9837 directly accessible, connect it to an nearby pin, protected by an resistor.

(3) Because the NCO (AD9837) is the interesting part but the OPV is not, it would be a very good idea to use an OPV which could be easily replaced.
There are not so much distributors (expensive shipment) for this part and soldering of such an little component is also very difficult.

Best regards,
Michael B.