2 Power supply management
2.1 Power supplies
The STM32U575/585 devices require a 1.71 to 3.6 V operating voltage supply (V
DD
).
The independent supplies listed below, can be provided for specific peripherals:
• V
DD
= 1.71 V to 3.6 V
V
DD
is the external power supply for the I/Os, the internal regulator and the system analog such as reset,
power management and internal clocks. V
DD
is provided externally through the VDD pins.
• V
DDA
= 1.58 V (COMPs) / 1.6 V (DACs/OPAMPs) / 1.62 V (ADCs) / 1.8 V (VREFBUF) to 3.6 V
V
DDA
is the external-analog power supply for A/D converters, D/A converters, voltage reference buffer,
operational amplifiers and comparators. The V
DDA
voltage level is independent from the V
DD
voltage. The
VDDA pin must preferably be connected to V
DD
voltage supply when these peripherals are not used.
Note: In case the VDDA pin is left at high impedance or is tied to VSS, the maximum input voltage that can be applied
on the I/Os with "_a" I/O structure, is reduced (refer to device datasheet for more details).
• V
DDSMPS
= 1.71 V to 3.6 V
V
DDSMPS
is the external power supply for the SMPS step-down converter. It is provided externally through
the VDDSMPS pin, and must be connected to the same supply as VDD pin.
• V
LXSMPS
The VLXSMPS pin is the switched SMPS step-down converter output.
• V
DD11
V
DD11
is a digital core supply provided through the internal SMPS step-down converter VLXSMPS pin. Two
VDD11 pins are present only on packages with internal SMPS, connected to a total of 4.7 µF (typical)
external capacitors.
• V
CAP
V
CAP
is the digital core supply, from the internal LDO regulator. VCAP pins (one or two) are present only on
packages with LDO only (no SMPS), connected to a total of 4.7 µF (typical) external capacitor.
Note: – In case there is two VCAP pins (UFBGA169 package), each pin must be connected to a 2.2 µF capacitor,
for a total around 4.4 µF (maximum 4.7 µF).
– The SMPS power supply pins (VLXSMPS, VDD11, VDDSMPS, VSSSMPS) are available only on packages
with SMPS. In such packages, the STM32U575/585 devices embed two regulators, one LDO and one
SMPS in parallel, to provide the V
CORE
supply to digital peripherals. A 4.7 μF total external capacitor and a
2.2 µH coil are required on VDD11 pins.
– The Flash memory is supplied by V
CORE
and V
DD
.
• V
DDUSB
= 3.0 V to 3.6 V
V
DDUSB
is the external-independent power supply for USB transceivers. The V
DDUSB
voltage level is
independent from the V
DD
voltage. The VDDUSB pin must preferably be connected to V
DD
voltage supply
when the USB is not used.
Note: In case the VDDUSB pin is left at high impedance or is tied to VSS, the maximum input voltage that can be
applied on the I/Os with "_u" I/O structure, is reduced (refer to device datasheet for more details).
• V
DDIO2
= 1.08 V to 3.6 V
V
DDIO2
is the external power supply for 14 I/Os (port G[15:2]). The V
DDIO2
voltage level is independent from
the V
DD
voltage, and must preferably be connected to V
DD
when PG[15:2] are not used.
Note: On small packages, V
DDA
, V
DDIO2
or V
DDUSB
independent power supplies may not be present as a dedicated
pin, and are internally bonded to a VDD pin. They are neither not present when the related features are not
supported on the product.
• V
BAT
= 1.65 V to 3.6 V (functionality guaranteed down to V
BOR_VBAT
minimum value, refer to the product
datasheet)
V
BAT
is the power supply when V
DD
is not present (through power switch) for RTC, TAMP, external clock
32 kHz oscillator, backup registers and optionally backup SRAM.
AN5373
Power supply management
AN5373 - Rev 1
page 3/37