EFR32xG1 based radio boards use 1.0uF capacitor at DC-DC output by default, but the recommended value is 4.7uF for new designs. The EFR32xG1 software defaults to using 1.0 µF, use of 4.7 µF on EFR32xG1 requires modifications in the software. This KBA provides details how to do this modification.
The following methods are valid for Flex SDK 2.4. For other SDK versions, the folder paths or line numbers might be different.
There are 2 options to do this software modification:
1. Look for the following file in your computer: "C:\SiliconLabs\SimplicityStudio\v4\developer\sdks\gecko_sdk_suite\v2.4\platform\emlib\inc\em_emu.h"
Lines 725-752 are responsible for choosing if 1uF or 4.7uF capacitor is present at the DC-DC output. By default, the software uses 1uF for EFR32xG1 series, in order to change that to 4.7uF the following modification should be made:
Swap "emuDcdcLnCompCtrl_1u0F" (line 737) with "emuDcdcLnCompCtrl_4u7F" (line 751). This will make 4.7uF the default value.
2. Place line "#define _SILICON_LABS_GECKO_INTERNAL_SDID_80" in a comment section in the part specific header file (e.g. "efr32mg1p233f256gm48.h"). You can find this file at "C:\SiliconLabs\SimplicityStudio\v4\developer\sdks\gecko_sdk_suite\v2.4\platform\Device\SiliconLabs\EFR32xG1x\Include" folder.