On both reference designs for swrc185 (CC85XX+CC2590) and swrc232 (CC85XX+CC2590+Antenna Diversity) the following cap values are shown:
AVDD_LNA => 18pF + 1nF
AVDD_PA2 => 1nF (other cap is DNM)
AVDD_BIAS => 1nF
The CC2590 datasheet shows in Figure 2 for the CC2590EM the following:
AVDD_LNA => 18pF + 1nF
AVDD_PA2 => 27pF + 1nF
AVDD_BIAS => 1nF
It is mentioned in the datasheet that the caps on AVDD_LNA and AVDD_PA2 can affect resonance (no mention of this for AVDD_BIAS).
I would like to know what the customer should follow (for AVDD_LNA and AVDD_PA2) and is it expected that this might require tuning based on the trace inductance? I would also like to know if it is OK to have a larger value cap on AVDD_BIAS since it appears to only be for bypass (and shouldn't affect LNA/PA resonance)?
Kind Regards,
Marc
