We are using AD9783 for our TETRA base station Transmitter.
The baseband I/Q data from FPGA is fed to AD9783 in DCI/DATA parallel LVDS at a clock speed of 5.76MSPS.
When the temperature changes there is a significant degradation in the ACLR performance.
We tested this in the thermal chamber.
When the temperature reaches +50 DegC the ACPR degrades. When we keep the temperature constant at +50DegC, in about 5 minutes the distortion reduces and the ACLR readings comes back to normal performance.
The same behavior is observed when we reduce the temperature also. When the temperature reaches about +30 DegC (while coming down from +50DegC), the ACLR performance degrades.
This seems to be a thermal behavior.
I suspect whether the calibration procedure mentioned in the datasheet need to be done for the digital interface.
But I'm using only 5.76MHz clock. Or will I have an advantage if I use the DCO for latching the data.