Hello,
I obtained a CC1125 ETSI EN 300 220 Cat 1 868 MHz Development kit and modified it to 434 MHz. I am obtaining some very impressive results which are quite similar to those announced in the datasheet.
Conditions: fxosc TCXO 40 Mhz, 1.2 kbps 2-FSK, 4-kHz Dev and 10 kHz Channel filter.
Sensitivity= -122 dBm Cat 1
Adjacent channel selectivity 12.5 kHz= 60 dB Cat 1
Saturation adjacent channel 12.5 kHz= 93 dB Cat 1
Blocking 2 MHz= 83 dB -3 dB from Cat1, -2 dB from datasheet
Blocking 10 MHz= 88 dB Cat 1
Spurious response -124 kHz= 60 dB Cat 1
As you can see every requirement for ETSI EN 300 220 Cat 1 is met except for the Blocking at 2 MHz. I will use a narrow SAW filter as advised to pass the Cat 1 Blocking requirement but my question is:
Do you have some register tweak or any other tip to improve the Blocking without the use of a narrow-band SAW filter? My final application is for 459 MHz and it is quite complicated to find an adequate standard SAW filter at those frequencies for the Cat 1 purpose.
I checked the Application Note AN122 and I used the FS_CHP to 3F without much succes. How can I manage with the Dev kit to configure FS_CHP to 3F after calibrating the PLL?
Thanks a lot.
