We are using DDS AD9851 in our systems..
We have 2 DDS which are driven from one clock frequency (20MHz) with the stability +-20ppm.
PLL * 6.
We are using DDS for phase-shifting device.
The first dds (sin) has output frequency 2000 000 Hz
Another DDS has a frequency 2000 015 Hz
If one of the DDS (or both) termally shocked - we have troubles with signals transformed..
For example, if we change the temperature of our DDS slowly from 25 to 60 grad, we have slow temperature drift..
If we termally shock only one DDS (e.g. with the help of hot air from soldering station) we have very big visible changes of the output signals..
So, the question is: is there a temperature drift of the sin wave generated by DDS? sin form? frequency?
How to reduce the influence of the temperature on the output of DDS?