In case 5V_VIN, E5V, 5V_USB_CHGR, 3V3, or STD_ALONE_5V is used to power the STM32WL Nucleo-64
board, this power source must comply with the EN-60950-1: 2006+A11/2009 standard and must be Safety Extra
Low Voltage (SELV) with limited power capability.
If the power supply is 3V3 or STD_ALONE_5V, the ST-LINK is not powered and cannot be used.
Power supply input from STLINK-V3E USB connector (default setting)
The STM32WL Nucleo-64 board and shield can be powered from STLINK-V3E connector CN1 (5 V) by placing a
jumper between pins 1-2 of JP5, “5V_SEL”, as illustrated in
. This is the default setting.
Figure 11.
Power supply input from STLINK-V3E USB connector with PC (5 V, 500 mA maximum)
If the USB enumeration succeeds, the 5V_USB_STLK power is enabled, by asserting the T_PWR_EN signal from
U9 STLINK-V3 STM32F723IEK6. This pin is connected to the U5 STMPS2151STR power switch, which powers
the board. The U5 STMPS2151STR power switch features also a current limitation to protect the PC in case of a
short-circuit on board. If an overcurrent higher than 500 mA occurs on board, the LED4 red LED is lit.
The Nucleo board and its shield can be powered from ST-LINK USB connector CN1, but only the ST-LINK circuit
gets power before USB enumeration, because the host PC only provides 100 mA to the board at that time.
During the USB enumeration, the Nucleo board requires 500 mA power from the host PC.
UM2592
Power supply
UM2592
-
Rev 1
page 17/49
