Re: AD9850/51 module pc boards

Henning Weddig
 

Terry,

I am missing a lof of decoupling caps close to the Vcc pins of the AD9850. Plöease have a look on the AD9850 data sheet, a lot of .1 µF caps are used there, althoug not easily seen where they belong to. My guess as they are on the bottom side they are close to the AD9850 pins too.

Another hint: the Analog Devicers app note "A Technical Tutorial
on Digital Signal Synthesis" from page 45 on gives good reasons to use a transformer on the DAC outputs!

Henning Weddig

DK5LV


Am 30.09.2018 um 05:34 schrieb Terry VK5TM:

Updated pics with the 3.3v reg underneath the Xtal osc.

I have moved some things around to shorten the length of tracks between IC output, transformer and pin at the edge of the pcb.

Will leave this alone for a day or two, firstly so any comments can be added/updated and secondly, I find getting away from a design sometimes suggests improvements that can be made or something shows that has been missed (like a power track missing in the first set of pics).

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