Part Number: LP-CC2651P3
I have loaded the rfDiagnostics project on a CC2651 launchpad. When I output a CW signal, the measured frequency is off by -60ppm. I suspect this is due to excessive load capacitance. The datasheet states
"Adjustable load capacitance is integrated into the device. External load capacitors are required for systems targeting compliance with
certain regulations. See the device errata for further details."
The datasheet specifies the load capacitance as 7pF typical, The launchpad contains two 7.5pF capacitors, for a total external capacitance of 3.75pF plus parasitics. So I suspect that the on-chip load capacitance is the reason for the excess.
I looked at the TRM and errata sheet, and I cannot figure out how to disable the on-chip capacitance?
Regards,
Andy
