Figure 2.
STM32U575xQ and STM32U585xQ power supply overview (with SMPS)
USB transceiver
Core
SRAM1
SRAM2
SRAM3
SRAM4
Digital
peripherals
LSE crystal 32kHz oscillator
Backup registers
RCC_BDCR register
RTC
TAMP
BKPSRAM
V
DDA
domain
Backup domain
Standby circuitry
(Wakeup logic, IWDG)
LDO regulator
Low-voltage detector
I/O ring
V
CORE
domain
Temperature sensor
Reset block
3 x PLL
Internal RC oscillators
Flash memory
VDDUSB
VDDIO2
V
DDIO1
I/O ring
PG[15:2]
V
DDIO2
VDDA
VSSA
VSS
VSS
V
DDIO2
domain
V
DD
domain
V
CORE
VSS
VDD
VBAT
2x VDD11
SMPS regulator
Voltage regulator
VLXSMPS
VDDSMPS
VSSSMPS
2 x A/D converters
2 x comparators
2 x D/A converters
2 x operational amplifiers
Voltage reference buffer
In devices without SMPS, the I/Os and system analog peripherals (such as PLLs and reset block) are fed by V
DD
supply source. The V
CORE
power supply for digital peripherals and memories is generated from the LDO.
Note:
If the selected package has the SMPS step-down converter option but the SMPS is not used by the application
(and the embedded LDO is used instead), it is recommended to set the SMPS power supply pins as follows:
•
VDDSMPS and VLXSMPS connected to VSS
•
VDD11 pins connected to VSS through two 2.2 µF capacitors as in normal mode
2.1.1
Independent analog peripherals supply
To improve ADC and DAC conversion accuracy and to extend the supply flexibility, the analog peripherals have
an independent power supply that can be separately filtered and shielded from noise on the PCB.
The voltage supply input of the analog peripherals is available on a separate VDDA pin. An isolated supply
ground connection is provided on VSSA pin.
The V
DDA
supply voltage can be different from V
DD
. After reset, the analog peripherals supplied by V
DDA
are
logically and electrically isolated and therefore are not available. The isolation must be removed before using
these peripherals, by setting the ASV bit in the PWR_SVMCR register, once the V
DDA
supply is present.
The V
DDA
supply can be monitored by analog voltage monitors (AVM), and compared with two thresholds
(1.6 V for AVM1 or 1.8 V for AVM2). For more details, refer to the device datasheet and section 'Peripheral
voltage monitoring (PVM)' of the reference manual.
When a single supply is used, the VDDA pin can be externally connected to the same V
DD
supply, through an
external filtering circuit, in order to ensure a noise-free V
DD
reference voltage.
AN5373
Power supplies
AN5373
-
Rev 1
page 5/37
