6.3.8
Programing/debugging when the power supply is not from STLINK-V3E (5V_STLK)
5V_VIN, 5V_PM, 5V_DC or 5V_UCPD can be used as an external power supply, in case the current consumption
of the STM32L562E-DK Discovery kit, with expansion boards, exceeds the allowed current on USB. In such a
condition, it is still possible to use USB for communication for programming or debugging only.
In this case, it is mandatory to power the board first using 5V_VIN, 5V_PM, 5V_DC or 5V_UCPD then connect a
USB cable to the PC. Proceeding this way, the enumeration succeeds thanks to the external power source.
The following power sequence procedure must be respected:
1.
Connect the JP4 jumper according to the external 5V power source selected.
2.
Connect the external power source according to JP4.
3.
Power ON the external power supply.
4.
Check 5V GREEN LED LD12 is turned ON.
5.
Connect the PC to the CN17 USB connector.
If this sequence is not respected, the board may be powered by V
BUS
first from STLINK-V3E, and the following
risk may be encountered:
•
If more than 500 mA current is needed by the board, the PC may be damaged or current can be limited by
PC, As a consequence the board is not powered correctly.
•
500mA is requested at enumeration, so there is a risk that request is rejected and enumeration does not
succeed if the PC does not provide such current. Consequently, the board is not powered (LED LD12
remains OFF).
6.3.9
External power supply output
5V: When the STM32L562E-DK board is powered by 5V_STLK, 5V_VIN, 5V_PM, 5V_UCPD or 5V_CHG, the 5V
on ARDUINO
®
CN18 pin 5 can be used as an output power supply for an expansion board plugged on CN18. In
this case, the maximum current of the power source specified in
Table 7. Power supply capabilities
must be
respected.
3V3: ARDUINO
®
CN18 pin 4 can also be used as a power supply output. The current is limited by the maximum
300 mA current capability of the U46 DC-DC converter (TPS62743), concerning the STM32L562E-DK board and
its shield consumption.
6.3.10
Internal power supply
For all general information concerning Design recommendations for STM32L562QEI6QU with INTERNAL SMPS,
and design guide for ultra-low-power applications with performance, refer to the application note
Getting started
with STM32L5 Series hardware development
(AN5211) at the
website.
3V3
Regardless of the 5V power source, a U46 DC-DC converter is used to deliver a fixed 3.3 V power supply, with a
current capability of 300 mA. This power source of 3.3 V is shared between the STM32L562E-DK and its
expansion board.
1V8
Regardless of the 5V power source, a U44 DC-DC converter is used to deliver a fixed 1.8 V voltage, with a
current capability of 300 mA. This power source of 3.3 V is shared between the STM32L562E-DK and its
expansion board.
When VDD_MCU is connected to 1V8, the MCU switch in LDO mode instead of SMPS mode.
Warning:
The power sequence is not respected when using 1V8 VDD. Refer to the application note Getting
started with STM32L5 Series hardware development (AN5211), and STM32L5xx product
datasheets for power sequencing.
DYN_OUT
The STM32L562E-DK Discovery kit offers the possibility to make dynamic current consumption measurements
with a range of 300nA to 150mA. This function is done according to an energy meter embedded part. Refer to
Section 6.19 MCU energy meter tools
.
UM2617
Power supply
UM2617
-
Rev 2
page 18/61