Power Control (Pwr); Power Supplies - ST STM32L4 5 Series Reference Manual

Power control (PWR)

5 Power control (PWR)
5.1

Power supplies

The STM32L4x5/STM32L4x6 devices require a 1.71 V to 3.6 V operating supply voltage
(V ). Several peripherals are supplied through independent power domains: V
DD
V , V
DDIO2
supply on the V
• V
DD
V
DD
analog such as reset, power management and internal clocks. It is provided externally
through VDD pins.
•
VDD12 = 1.05 V to 1.32 V
External power supply, connected to V
connected to an external SMPS. It is provided externally through VDD12 pins and only
available on packages with the external SMPS supply option.
•
V
DDA
V
DDA
reference buffer, operational amplifiers and comparators. The V
independent from the V
these peripherals are not used.
• V
DDUSB
V
DDUSB
voltage level is independent from the V
connected to V
•
V
DDIO2
V
DDIO2
is independent from the V
PG[15:2] are not used.
•
V
LCD
The LCD controller can be powered either externally through VLCD pin, or internally
from an internal voltage generated by the embedded step-up converter. VLCD is
multiplexed with PC3 which can be used as GPIO when the LCD is not used.
• V
BAT
V
BAT
(through power switch) when V
small packages without dedicated pin.
•
V
REF-
V
REF+
internal voltage reference buffer when enabled.
When V
When V
V
REF+
The internal voltage reference buffer supports two output voltages, which are
configured with VRS bit in the VREFBUF_CSR register:
–
150/1830
, V . Those supplies must not be provided without a valid operating
DDUSB LCD
pin.
DD
= 1.71 V to 3.6 V
is the external power supply for the I/Os, the internal regulator and the system
= 1.62 V (ADCs/COMPs) / 1.8 V (DACs/OPAMPs) / 2.4 V (VREFBUF) to 3.6 V
is the external analog power supply for A/D converters, D/A converters, voltage
DD
= 3.0 V to 3.6 V
is the external independent power supply for USB transceivers. The V
when the USB is not used.
DD
= 1.08 V to 3.6 V
is the external power supply for 14 I/Os (Port G[15:2]). The V
DD
= 2.5 V to 3.6 V
= 1.55 V to 3.6 V
is the power supply for RTC, external clock 32 kHz oscillator and backup registers
, V
REF+
is the input reference voltage for ADCs and DACs. It is also the output of the
< 2 V, V must be equal to V
DDA REF+
≥ 2 V, V must be between 2 V and V
DDA REF+
can be grounded when ADC and DAC are not active.
V around 2.048 V. This requires V
REF+
DocID024597 Rev 5
, bypassing internal regulator when
CORE
voltage. V should be preferably connected to V
DDA
voltage. V
DD
voltage and should preferably be connected to V
is not present. VBAT is internally bonded to VDD for
DD
DDA
equal to or higher than 2.4 V.
DDA
voltage level is
DDA
should be preferably
DDUSB
DDIO2
.
.
DDA
RM0351
,
DDA
when
DD
DDUSB
voltage level
when
DD