Power Supply Input From An Stlink-V3E Usb Connector (Default Setting): 5 V/500 Ma; Figure 9. Jp4 [1-2]: 5V_Stlk Pwr Source - ST STM32L562E-DK User Manual

6.3.2

Power supply input from an STLINK-V3E USB connector (default setting): 5 V/500 mA

5V_STLK is a DC power with limitation from an STLINK-V3E USB connector (CN17), the USB Micro-B connector
of STLINK-V3E. In this case, the JP4 jumper must be on pin [1-2] to select the 5V_STLK power source on the
JP4 silkscreen. This is the default setting. If the USB enumeration succeeds, the 5V_STLK power is enabled, by
asserting the PWR_ENn signal (from the STLINK-V3E MCU). This pin is connected to a 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 STLINK-V3E USB connector (CN17) can power the Discovery board with its shield, but only an STLINK-V3E
circuit has the power before USB enumeration because the host PC only provides 100 mA to the board at that
time. During the USB enumeration, the Discovery board asks for a 500 mA current to the host PC. If the host can
provide the required power, the enumeration finishes by a SetConfiguration command. Then the power switch and
the green LED (LD12) turned ON. Thus, the Discovery board with its shield can consume 500 mA current, but no
more. If the host is not able to provide the requested current, the enumeration fails. Therefore, the power switch
remains OFF and the MCU part including the expansion board is not powered. As a consequence, the green LED
(LD12) remains turned OFF. In this case, it is mandatory to use another power supply.
The 5V_STLK power source configuration for jumper JP4 [1-2] is described in
UM2617 - Rev 7
Figure 9.
LCD 240x240 + CTP
JP4 [1-2]: 5V_STLK PWR SOURCE
5V PWR (LD12)
UM2617
Power supply
Figure 9.
ST-LINK USB
(bottom side)
(CN17)
5V PWR source
(JP4 [1-2])
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