Bruce, I assume you are talking about Figure 12 of UG-313. If an LCD scope is not in single shot mode it will show a composite of many cycles which will hide the stairsteps (especially if the frequency control word is not a nice round binary number) in the fuzz.
I think the 0.1uF capacitor on IOUT on the evaluation board also helps roll off the stairsteps. Tim N3QE On Thu, Nov 17, 2016 at 11:49 PM, Bruce Griffiths < [email protected]> wrote: > With no internal PLL to generate a higher internal frequency than the > 25MHz MCLK, that 1MHz waveform looks a bit too smooth for an unfiltered > 1MHz output. > Bruce > > On Friday, 18 November 2016 5:12 PM, Richard (Rick) Karlquist < > [email protected]> wrote: > > > Trying to figure out what "Iout Full Scale" means on the AD9832. > Some time nuts may have used this one. > > On page 7 of this doc: > > http://www.analog.com/media/en/technical-documentation/ > user-guides/UG-313.pdf > > It shows the AD9832 output as 572 mV peak to peak > across 300 ohms. This works out to 1.9 mA peak to > peak current through the resistor. But Rset on the > board is 3.9K, which is supposed to give a value > for so-called "Iout Full Scale" of 3.878 mA. > > I would have thought (just guessing) that peak to > peak output current would be equal to Iout Full > Scale, but it appears to be only half of that. > > Can anyone clarify this? > > Rick > _______________________________________________ > time-nuts mailing list -- [email protected] > To unsubscribe, go to https://www.febo.com/cgi-bin/ > mailman/listinfo/time-nuts > and follow the instructions there. > > > > _______________________________________________ > time-nuts mailing list -- [email protected] > To unsubscribe, go to https://www.febo.com/cgi-bin/ > mailman/listinfo/time-nuts > and follow the instructions there. > _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
