ST STM32L562E-DK, User Manual, Page: 14 / 61

6.3.2 Power supply input from STLINK-V3E USB connector (default setting): 5V/500mA
5V_STLK is a DC power with limitation from CN17 STLINK-V3E USB connector, the USB type Micro-B connector
of STLINK-V3E. In this case, the JP4 jumper must be on pin [1-2] to select 5V_STLK power source on 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
STMPS2151STR, which powers the board. This power switch features also a 500 mA current limitation to protect
the PC in case of an onboard short-circuit.
The Discovery board and its shield on it can be powered from the CN17 STLINK-V3E USB connector, but only
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 500 mA current to the host PC. If
the host is able to provide the required power, the enumeration finishes by a
SetConfiguration command and
then, the power switch is switched ON, the green LED LD12 turned ON, thus the Discovery board and its shield
on it 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.
5V_STLK power source configuration for jumper JP4 [1-2] is described in
Figure 9 .
Figure 9. JP4 [1-2]: 5V_STLK PWR SOURCE
6.3.3 5V_VIN power source: 7 to 12 V, 800 mA maximum
5V_VIN is the DC power coming from the CN18 ARDUINO
®
connector. In this case, the JP4 jumper must be on
pin [3-4] to select the 5V_VIN power source on JP4 silkscreen.
A dedicated LDO (U10) is used to generate the 5V_VIN from the 7 to 12 V VIN input.
5V_VIN power source configuration for jumper JP4 [3-4] is described in
Figure 10 .
UM2617
Power supply
UM2617 - Rev 2
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