search

sinara-hw / Urukul

4 channel 1GS/s DDS (AD9910 or AD9912 variant)
14 stars 8 forks source link

XO load resistance #11

Closed hartytp closed 6 years ago

hartytp commented 6 years ago

Output current must be <=24mA according to the data sheet. Let's go for a total load of 150Ohm. With a 100R-50R divider, the peak-peak signal is still about 1V, which should be more than enough (particularly, since it's a square-wave output).

jordens commented 6 years ago

I think in practice it was actually more than that. When I looked at it on a scope I was actually worried about it being too much.

hartytp commented 6 years ago

Currently, we have a 50R-50R divider, so I'd expect more like 1.65Vp-p. Did you see more than that?

gkasprow commented 6 years ago

Now we have 100:50 divider.