Figure 9. 5V Jumper Selection Jp3[1-2]: Stlk Power Source - ST STM32U5 Nucleo-64 User Manual

STLK is a 5 V DC power with limitations from the STLINK-V3EC USB connector (CN1). In this case, the 5V
jumper selection (JP3) must be on pin [1-2] to select the STLK power source on the JP3 connector. This is
the default setting. If the USB enumeration succeeds, the STLK power is enabled, by asserting the T_PWR_EN
signal from STLINK-V3EC. This pin is connected to over‑voltage protection (U5) with the management of the
maximum current delivery.
The Nucleo-64 board and its shield can be powered from the STLINK-V3EC USB connector (CN1), but only the
STLINK-V3EC circuit is powered before USB enumeration because the host PC only provides 100 mA to the
board at that time. During the USB enumeration, the Nucleo-64 board requests 500 mA power from the host PC.
• If the host can provide the required power, the U5 power switch is enabled, the green LED (LD3) is turned
ON, and the Nucleo-64 board and its shield can consume up to 500 mA.
• If the host is not able to provide the requested current, the enumeration fails. the U5 power switch remains
OFF and the MCU part including the extension board is not powered. As a consequence, the green LED
(LD3) remains OFF. In this case, it is recommended to use an external 5 V power source.
STLK configuration: 5V jumper selection JP3[1-2] must be connected as shown in
UM3062 - Rev 1
Figure 9. 5V jumper selection JP3[1-2]: STLK power source
STM32
microcontroller
UM3062
Power supply and power selection
Figure 9.
USB STLINK-V3EC
(CN1)
5V LED
(LD3)
5V_STLK selection
(JP3 [1-2])
page 18/45