LR1110
User Manual
Rev.1.0
UM.LR1110.W.APP
March 2020
76 of 130
Semtech
Figure 9-6: HP PA Output Power vs.
TxPower
9.3 PA Current Consumption
9.3.1 Low Power PA
Figure 9-7: IDDTX vs TxPower, Low Power PA, DC-DC Configuration
shows the impact of the supply voltage for three
PaDutyCycle
settings (0, 4 and 7) in DC-DC configuration.
At a given supply voltage, a higher
PaDutyCycle
setting increases the device current consumption. At a given
PaDutyCycle
setting, the current consumption is optimum for a supply voltage equal or greater to 3.3V, therefore the plots for 3.3 V and
3.7 V are superimposed. A power supply of 1.8V will be not be as power efficient than 3.3V or above, resulting in a higher
current consumption.
For example:
•
For 3.7 V,
PaDutyCycle
=0 the current consumption is approx. 28 mA, for
PaDutyCycle
=4 approx. 47 mA and for
PaDutyCycle
=0 approx. 62mA.
•
For
PaDutyCycle
=4, the current consumption is approx. 47 mA for 3.3 V and 3.7 V, and approx. 49 mA for 1.8 V.
