SKY65367 + CC112x/CC120x 169MHz Reference Design

CC112x Skyworks 30 dBm EM Ref Design Italy Rev 1_0.zip

Hi Tom,

We have updated this ref design with the option for an inline attenuator. The design files are attached.

Regards, Richard

Hello, we just follow this ref desing, but with 2 layer PCB design.

With TX power @ 0dBm the signal we can see on signal analyzer is down to -43.88dBm (see attached picture) and we use  V2 to GND and V1 to 2.2V.

How can I troubleshoot what was wrong with this design? Is there any tool to show me what was wrong?

We would like to redesign PCB. Perhaps make an extra version with 4 layer PCB as well.

BR.Tom.

- Check that the input of the FEM is as expected.

- Check that all control signal to the FEM is as expected

- Check that all component values are mounted correctly

I would expect poorer performance with 2 layer but as higher harmonics, low output power is probably due to something else.

Hi,

Do you have the C26 component in your schematic ? This should not be assembled if you are using the inline attenuator.

The output power levels you are measuring are not related to the number of layers in the PCB design.

Regards, Richard

The input can be checked by removing the last component connected to the input and place a semi rigid cable on the non input side of the serial dongle removed. Or in other words, checking the output of the CC112x/ CC12xx as close as possible to the FEM without having the FEM in the circuit.