Hello Gui, thanks for investigating time for me.
I have the following setup:
4 0000 //Set AFE to normal mode
6 6000 //Set AFE to 12X data rate
8 0012 //Settings AFE:MSB-first, ADC_Output_format:2's complement, ADC resolution:12bit
34 4000 //LNA_GAIN[14:13] 10 - 12dB;
54 0840 //4x mode, TGC mode and differential mode
Other settings --> default values. -->(no termination is activated)
What i have done in the meantime:
I played a little bit with the filter LNA_INTEGRATOR_DISABLE(LNA_HPF_DISABLE) and PGA_INTEGRATOR_DISABLE(PGA_HPF_DISABLE) which are normally enabled.
disable(reg 34 to 5000) LNA_INTEGRATOR_DISABLE(LNA_HPF_DISABLE)--> no significant change in amplitude
disable(reg 33 to 0010) PGA_INTEGRATOR_DISABLE(PGA_HPF_DISABLE)--> amplitude increase and the ADC comes into saturation. I change the value Vcntlp-Vcntlm to 300mV. Now i recevie an amplitude of 580mV.
The expected value like in the table on page 52 is now 27,39dB. The value i get is 25,8dB. The result is better, but i miss ~2,5dB.
Maybe it is because of a not perfect signal level measurement on the input of the AFE. (imeasrue on a 820ohm resistor on the inxP pin before the 100n coupling capacity against GND)
Hopefully it is now more clear.
Regards,
Stefan