Table 8. Rf Transceiver Configuration; Figure 20. Hp Configuration With Dc Switches; Figure 21. Lp Configuration With Dc Switches - ST STM32WL Series User Manual

3. HP/LP: Combined High and Low power modes.
In this case, R13, R14, R12, and R15 are OFF, and U1 and U5 are ON.
The choice between both Tx paths can be done dynamically thanks to the two XS3A1T3157 DC switches (U1 and
U5) controlled by SW_CTRL (GPIO from the STM32WL series MCU):
• The transmit high output power amplifier (PA HP) is supplied from the PA regulator (REG PA) up to 3.1 V.
For this, the REG PA must be supplied directly from VDDSMPS.
• The transmit default output power amplifier (PA LP) can be supplied from the PA regulator (REG PA) up to
1.35 V. For this, the REG PA must be supplied from the regulated VFBSMPS supply at 1.55 V
In addition, PC5 and PC3 are I/Os inside the STM32WL5MOC module and are dedicated to the RF front-end
switch control.
associated DC switches.
Transmit high output power
Transmit low output power
Receive
UM3127 - Rev 1
Figure 20.
VDDRF
n GPIOs
Figure 21.
VDDRF
n GPIOs
Table 8 describes the truth table of the RF modes based on the STM32WL5MOC module and
Table 8.
RF transceiver configuration
HP configuration with DC switches
DC switch DC switch
VDDPA VDDRF1V55 RFO_HP VR_PA RFO_LP
SRM32WL5MOC module
VDD
GND
LP configuration with DC switches
DC switch DC switch
VDDPA VDDRF1V55 RFO_HP VR_PA RFO_LP
SRM32WL5MOC module
VDD
GND
RF transceiver configuration
SW_RF
LOW
HIGH
HIGH
UM3127
Hardware layout and configuration
Antenna
Antenna
PC5 PC3
HIGH HIGH
LOW HIGH
HIGH HIGH
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