I am trying to use POWER DOWN pin to power up/down the DDS externally. I switch on the DDS to output the sine wave for some times. Then I turn off the output by power down. But I find that the output (DC) is not zero volt after power down. How can I make it totally zero volt output? Also, I find it pretty strange that each time I power it back up, the sine wave started at different phase point instead of zero. Why is it?
One more question about the IO Update, I monitor the output, I find that every time I issue IO Update, there will be a very short pulse output from the channel. Some times this pulse with magnitude ranged from 0.5 to 4V, I am worrying that will affect other electronics connecting to the output channel. Is there any way to get rid of that spike?