Figure 3. Power Supply Scheme For Stm32U575X And Stm32U585X (Without Smps) - ST STM32U575 Series Application Note

• The VBAT pin can be connected to an external battery to preserve the content of the Backup domain:
– When VDD is present, the external battery can be charged on VBAT through a 5 kΩ or 1.5 kΩ internal
resistor. In this case, the user can insert a capacitor according to the expected discharging time (1 µF
is recommended).
– If no external battery is used in the application, it is recommended to connect the VBAT pin to V
a 100 nF external ceramic decoupling capacitor.
• The VDDUSB pin when present in a package can be connected to a ceramic capacitor of 100 nF.
The figures below details the power supply schemes for packages with and without SMPS.
Figure 3.
Caution: If there are two VCAP pins (UFBGA169 package), each pin must be connected to a 2.2 µF (typical) capacitor
(for a total around 4.4 µF).
AN5373 - Rev 1
Power supply scheme for STM32U575x and STM32U585x (without SMPS)
VBAT
1.65 – 3.6 V
3.3 V
VDDUSB
100 nF
VCAP
4.7 µF
V
DD
n x VDD
n x 100 nF
GPIOs
+ 1 x 10 µF
n x VSS
V
DDIO2
m x VDDIO2
m x 100 nF
+ 4.7 µF
GPIOs
m x VSS
V
DDA
VDDA
V
REF
100 nF
+1 µF
100 nF+ 1 µF
VSSA
Power switch
LDO
V
CORE
regulator
V
DDIO1
OUT
I/O
logic
IN
V
DDIO2
OUT
I/O
logic
IN
ADCs/
V DACs/
REF+
OPAMPs/
V
REF-
COMPs/
VREFBUF
AN5373
Power supply schemes
with
DD
Backup circuitry
(LSE, RTC, TAMP
backup registers,
backup SRAM)
V
CORE
Kernel logic
(CPU, digital
and
memories)
page 9/37