ST STM32L4P5AG User Manual page 12

If a short-circuit occurs on the board, the STMPS2151 power switch protects the USB port of the host PC against
a current demand exceeding 500 mA. In such an event, the LD3 LED lights up.
The STM32L4P5G-DK board can also be supplied from a USB power source not supporting enumeration, such
as a USB charger. In this particular case, the JP4 jumper must be ON as shown in
jumper and solder bridge
procedure results, and passes the power unconditionally to the board.
The LD5 green LED turns on whenever the whole board is powered.
6.2.2 Using STLINK-V3E along with powering through external power
It can happen that the board requires more than 300 mA of supply current. It cannot be supplied by host PC
connected to the STLINK-V3E USB port for debugging or programming the STM32L4P5AGI6PU. In such a case,
the board can be supplied through CN13 pin8 (Marked VIN on the board).
To do this, it is important to power the board before connecting it with the host PC, which requires the following
sequence to be respected:
1. Set the JP4 jumper in the E5V position,
2. Connect the external power source to CN13 pin8,
3. Check that the LD5 green LED is turned on,
4. Connect the host PC to the CN11 USB connector.
Caution: In case the board demands more than 300 mA and the host PC is connected via USB before the board is
powered from CN13 pin8, there is a risk that the following events to occur (Listed in reverse severity order):
1. The host PC is capable of supplying 300 mA (The enumeration succeeds) but it features no over-current
protection on its USB port. It is damaged due to over-current.
2. The host PC is capable of supplying 300 mA (The enumeration succeeds) and it has a built-in over-current
protection on its USB port, limiting or shutting down the power out of its USB port when the excessive
current demand from the is detected. This causes an operating failure of the STM32L4P5G-DK.
3. The host PC is not capable of supplying 300 mA (The enumeration fails). The STLINK-V3E does not
supply the rest of the from its USB port V
Table 4 details the jumper and solder bridge settings used for the power-supply configuration of the
STM32L4P5G-DK.
Jumper /solder
bridge
JP4 5 V source
selector
UM2651 - Rev 2
settings. STLINK-V3E bypasses STMPS2151 power, regardless of enumeration
line.
BUS
Table 4. Power-supply related jumper and solder bridge settings
Setting
STLK U5V E5V D5V CHGR
STLK U5V E5V D5V CHGR
STLK U5V E5V D5V CHGR
STLK U5V E5V D5V CHGR
STLK U5V E5V D5V CHGR
Table 4. Power-supply related
Configuration
Default setting.
STM32L4P5G-DK is supplied through the CN11 Micro-B USB
receptacle. It depends on the host PC USB port's powering
capability declared in the enumeration.
STM32L4P5G-DK is supplied through CN7 Micro-AB USB
receptacle.
STM32L4P5G-DK is supplied through CN13 pin 8.
STM32L4P5G-DK is supplied through CN13 pin 5.
STM32L4P5G-DK is supplied through CN11 Micro-B USB
receptacle.
This setting is applied to power the board through CN11 using
USB charger.
UM2651
Power supply
(1)
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