6.4
Power supply and power selection
6.4.1
External power supply input
The Nucleo board is designed to be powered by several DC power supplies. It is possible to configure the Nucleo
board to use any of the following sources for the power supply:
•
5V_STLK from CN1 STLINK-V3E USB connector
•
VIN (7 to 12 V) from CN8 ARDUINO
®
-included Zio connector or CN11 ST morpho connector
•
5V_EXT from CN11 ST morpho connector
•
5V_USB_C from CN15 USB Type-C
®
connector
•
5V_CHGR from CN1 STLINK-V3E USB connector
•
3V3 from CN8 ARDUINO
®
-included Zio connector or CN11 ST morpho connector
If VIN, 5V_EXT, or 3V3 is used to power a Nucleo-144 board, this power source must comply with the standard
EN
‑
60950
‑
1: 2006+A11/2009 and must be safety extra
‑
low voltage (SELV) with limited power capability.
The power supply capabilities are summarized in
Table 8.
Power sources capability
Input Power name
Connector pins
Voltage range
Max.
current
Limitation
5V_STLK
CN1 pin 1
JP6 [1-2]
4.75 to 5.25 V
500 mA
Maximum current depending on the presence or
absence of USB enumeration:
•
100 mA without enumeration
•
500 mA with enumeration OK
VIN / 5V_VIN
CN8 pin 15
CN11 pin 24
JP6 [3-4]
7 to 12 V
800 mA
From 7 to 12 V only and input current capability is
linked to input voltage:
•
800 mA input current when VIN = 7 V
•
450 mA input current when 7 V < VIN < 9 V
•
250 mA input current when 9 V < VIN < 12 V
5V_EXT
CN11 pin 6
JP6 [5-6]
4.75 to 5.25 V
500 mA
Maximum current depending on the power source
5V_USB_C
CN15
JP6 [7-8]
4.75 to 5.25 V
1 A
Maximum current depending on the USB host used
to power the Nucleo
5V_CHGR
CN1 pin 1
JP6 [9-10]
4.75 to 5.25 V
500 mA
Maximum current depending on the USB wall
charger used to power the Nucleo
3V3
CN8 pin 7
CN11 pin 16
JP5 pin 2
3.0 to 3.6 V
-
Maximum current depending on the 3V3 source.
Used when the ST-LINK part of PCB is not used or
removed. SB1 must be OFF to protect LDO U6.
5V_STLK
is a DC power with the limitation from the STLINK-V3E USB connector (USB Type Micro-B connector
of STLINK-V3E). In this case, the JP6 jumper must be on pin [1-2] to select the 5V_STLK power source.
This is the default setting. If the USB enumeration succeeds, the 5V_STLK power is enabled, by asserting the
T_PWR_EN signal from U6 STLINK-V3E MCU. This pin is connected to the U2 power switch, which powers
the board. This power switch also features a 500 mA current limitation, to protect the PC in case of an onboard
short-circuit.
The STM32U5 Nucleo-144 board with its shield can be powered from the CN1 STLINK-V3E USB connector, but
only the STLINK-V3E circuit has the power before USB enumeration because the host PC only provides 100mA
to the board at that time. During the USB enumeration, the Nucleo board asks for a 500mA power to the host PC.
•
If the host can provide the required power, the enumeration finishes by a
SetConfiguration
command
and then, the U2 power switch is switched ON, the Green LED LD5 is turned ON, thus the Nucleo board with
its shield can consume 500mA current, but no more.
UM2861
Power supply and power selection
UM2861
-
Rev 2
page 17/49
