Power Supply Management; Power Supplies - ST STM32U5 Getting Started

2

Power supply management

2.1

Power supplies

The STM32U5 devices require a 1.71 to 3.6 V operating voltage supply (V
The independent supplies listed below, can be provided for specific peripherals:
• V = 1.71 V to 3.6 V
DD
V is the external power supply for the I/Os, the internal regulator, and the system analog such as reset,
DD
power management, and internal clocks. V
• V = 1.62 V (ADCs/COMPs/DACs/OPAMPs) / 1.8 V (VREFBUF) to 3.6 V
DDA
V is the external-analog power supply for A/D converters, D/A converters, voltage reference buffer,
DDA
operational amplifiers, and comparators. The V
VDDA pin must preferably be connected to the V
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
V
DDSMPS
the VDDSMPS pin, and must be connected to the same supply as VDD pin when the SMPS is used in the
application. When the SMPS is not used, it is recommended to connect both V
ground.
• V
LXSMPS
The VLXSMPS pin is the switched SMPS step-down converter output.
Note: The SMPS output can not be used to power external components.
• V
DD11
V is a digital core supply provided through the internal SMPS step-down converter VLXSMPS pin.
DD11
VDD11 pins (two or three) are present only on packages with internal SMPS, connected to a total of 4.7 µF
(typical) external capacitors.
• V
CAP
V is the digital core supply, from the internal LDO regulator. VCAP pins (one or two) are present only on
CAP
packages with LDO only (without SMPS), connected to a total of 4.7 µF (typical) external capacitor.
Note: – In case there are two VCAP pins (UFBGA169 package), each pin must be connected to a 2.2 µF
capacitor, for a total around 4.4 µF.
– The SMPS power supply pins (VLXSMPS, VDD11, VDDSMPS, VSSSMPS) are available only on
packages with SMPS. In such packages, the STM32U5 devices embed two regulators, one LDO
and one SMPS in parallel, to provide the V
capacitor and a 2.2 µH coil are required on VDD11 pins.
– The flash memory is supplied by V
• V
DDUSB
V
DDUSB
independent from the V
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
DD11USB
V
DD11USB
packages and must be connected to VDD11.
• V
DDIO2
V
DDIO2
from the V
Note: On small packages, V
dedicated pin, and are internally bonded to a VDD pin. They are neither present when the related features
are not supported on the product.
AN5373 - Rev 6
= 1.71 V to 3.6 V
is the external power supply for the SMPS step-down converter. It is provided externally through
= 3.0 V to 3.6 V
is the external-independent power supply for USB transceivers. The V
voltage. The VDDUSB pin must preferably be connected to the V
DD
= 1.0 V to 1.26 V (only available on STM32U59x/5Ax/5Fx/5Gx devices)
is the external power supply for the USB transceiver. This supply is only available on specific
= 1.08 V to 3.6 V
is the external power supply for 14 I/Os (port G[15:2]). The V
voltage, and must preferably be connected to V
DD
, V , or V
DDA DDIO2
DD
is provided externally through the VDD pins.
DD
voltage level is independent from the V
DDA
voltage supply when these peripherals are not used.
DD
supply to digital peripherals. A 4.7 μF total external
CORE
and V .
CORE DD
when PG[15:2] is not used.
DD
independent power supplies may not be present as a
DDUSB
AN5373
Power supply management
).
voltage. The
DD
and V
DDSMPS LXSMPS
voltage level is
DDUSB
voltage
DD
voltage level is independent
DDIO2
to
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