LR1121
User Manual Rev 1.1
UM.LR1121.W.APP Mar 2023
94 of 130
Semtech
Proprietary & Confidential
www.semtech.com
9.3.3 High Frequency PA
Figure 9-12 shows the impact of the TxPower setting for three supply voltages in a DC-DC configuration.
The current consumption is optimum for a supply voltage equal or greater to 3.3V, therefore the plots for 3.3V and 3.7V are
superimposed. A power supply of 1.8V is not as power efficient as 3.3V or more, resulting in a higher current consumption.
Figure 9-12: IDDTX vs TxPower, High Frequency PA, DC-DC Configuration
Figure 9-13: shows the impact of the TxPower setting for three supply voltages in LDO configuration.
The supply voltage has no influence on the current consumption, which means that the plots for 1.8V, 3.3V, and 3.7V are
superimposed.
Figure 9-13: IDDTX vs TxPower, High Frequency PA, LDO Configuration
Figure 9-12 and Figure 9-13 show that the power efficiency of the High Frequency PA is maximized when the internal
DC-DC regulator is used at, or above, 3.3V.
To Next Page
Loading...
