5. Conclusions
1. The minimal BOM Tline match has nearly the same fundamental power, harmonic levels, and current consumption as the four-
element lumped element match, but with lower cost.
2. Both the ladder four-element match and the minimal BOM Tline match complies with the U.S. FCC (~ –41 dBm EIRP) and EU
ETSI (~ –30 dBm EIRP) harmonic limits with large (>10 dB) margin up to power levels of ~ 20 dBm.
3. The two-element minimal BOM match is ETSI and FCC-compliant up to a 13 dBm power level, while the ladder two-element match
complies up to 10 dBm.
4. Both the minimal BOM matches and the lumped element matches work well with the different package versions without significant
effects on the output spectrum. The power variation is usually less than 0.5 dB, which is less than the chip-to-chip variation.
5. All matches with all EFR32 package versions have less than ~0.5 dB power variation across the entire 2.4 GHz band.
6. Typical total IC current consumption is ~30 mA at 10 dBm and ~135 mA at 20 dBm power levels. For power levels up to 13 dBm,
Silicon Labs recommends that the PA be supplied from the internal dc-dc converter. The current does not vary excessively with
different packages.
7. The cost of the minimal BOM matches is significantly lower because only one affordable, external multilayer type SMD inductor is
used. The ladder matches are more expensive because film type inductors are used.
8. The sensitivity of the minimal BOM matches is the same or slightly better than that of their ladder counterparts.
AN930: EFR32 2.4 GHz Matching Guide
Conclusions
silabs.com
| Building a more connected world.
Rev. 0.4 | 17
