CC1352P7: RF interface compared with CC1352P

@RGW - curious about the changes in filtering.  Would this affect F3 and F4 harmonics emissions for the 915 MHz ISM band?  Did this affect any output matching, if the recommended Johanson balun is used?

If customer has used Johanson balun for both designs then we expect similar performance for both CC1352P and CC1352P7.

What levels of harmonics is the customer measuring ?

868 MHz or 915 MHz ?

We're in the 915 MHz ISM band.  The 4th harmonic at 3.66 GHz came in at 52 dBuV/m, so only 2 dB under the limit.  We can gain more margin if we adopt the duty cycle ruling, but that will limit our message payload size for all future use.  If the P7 chip is even 4-6 dB lower emissions in the third and fourth harmonics compared to the P1, then that would be a comfortable margin without any duty cycle restrictions.

If you are using the same RF filter, then the performance will be similar. 

With Johanson filter, then it is expected that you will need some duty cycling to pass the FCC regulations. You can always add an LC filter to remove the requirement of relying on duty cycling.

CC1352 IPC app note: https://www.ti.com/lit/swra629

Thanks - I'm using both the Johanson balun and their LPF on the output already, along with some pi matching networks that have mild LPF qualities.  I was just curious if you could elaborate on the comment where the P7 uses an updated design with improved filtering.  What kind of filtering was added inside the P7?  Is it a LPF to help with harmonics?  Or a BPF to help with RX sensitivity?  I'm just trying to understand what we should look for when evaluating this chip vs. the P1 variant.

It is the external passive filtering that has been improved on the P7 reference designs. Not the actual chip design itself.

Please send schematic and we can assist improving the harmonic performance.