Hi,
We using internal load capacitors the 48 MHz XO operating in 868 MHz band.
But we cannot find the how the internal capacitance change with temperature?
If we tune to 7pF at room temperature, and the internal capacitance array is 7.7 pf (+10%) at 85 degree, this variance will add to crystal temperature characteristics.
Regards
no-more-wires
Hi,
It seems the variation in the Cap array value against the temperature is very minimum when compared with the Drift in the Crystal. So, you can adjust the Cap array value at Room temperature to obtain a better Frequency Accuracy (as close as possible). The Crystal drift is the dominating factor here.
The following is the plot for Freq Drift versus temperature. This plot includes both Crystal + Cap array. The Crystal used for this test is NX2016SA 48.000MHz EXS00A-CS05517, which is on our reference designs.
Thanks,
PM
