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AZube.2
Associate III
April 26, 2022
Solved

Is the reduced power comsumption the only advantage of using the RFO_LP output respect RFO_HP? Can I use the same RF matching network for RFO_LP and RFO_HP outputs? Any disadvantage of using the same RF matching network for both outputs?

  • April 26, 2022
  • 2 replies
  • 1108 views

I am developing a hardware design using the STM32WLE5JCI6. As a reference, I am looking at projects "MB1842.PrjPcb" (reference design) and "MB1389.PrjPcb" (Nucleo-WL55JC1 design files)

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Best answer by Benoit MARCHAND

Hello,

Basically, yes, "only" advantage of using RFO_LP is to reduce current consumption. But this adavantage is huge if you are working on battery.

2nd advantage is to be able to set RF Output Power between -10 and -17dBm.

If you're not on battery and don't care current consumption and need to support different RF Output Powers below and above 15dBm, then you can decide to use only RFO_HP.

If you need to use both RFO_LP and RFO_HP, then you need 2 matching networks (you cannot connect RFO_LP and RFO_HP to a single matching network). As these 2 outputs have different impedances, it is far better for RF output power and current power consumption to use specific matching network BOMs for each of the outputs.

Hope this clarifies.

BR,

Benoit

2 replies

Benoit MARCHAND
Benoit MARCHANDBest answer
ST Employee
April 28, 2022

Hello,

Basically, yes, "only" advantage of using RFO_LP is to reduce current consumption. But this adavantage is huge if you are working on battery.

2nd advantage is to be able to set RF Output Power between -10 and -17dBm.

If you're not on battery and don't care current consumption and need to support different RF Output Powers below and above 15dBm, then you can decide to use only RFO_HP.

If you need to use both RFO_LP and RFO_HP, then you need 2 matching networks (you cannot connect RFO_LP and RFO_HP to a single matching network). As these 2 outputs have different impedances, it is far better for RF output power and current power consumption to use specific matching network BOMs for each of the outputs.

Hope this clarifies.

BR,

Benoit

AZube.2
AZube.2Author
Associate III
April 28, 2022

Hello,

Unsderstood, thank you for the answer!