Hardware layout
UM1670
18/32
UM1670 Rev 4
6.4
Power supply and power selection
The power supply is provided either by the host PC through the USB cable or by an external
5 V power supply.
The D1 and D2 diodes protect the 5 V and 3 V pins from external power supplies:
•
5 V and 3 V can be used as output power supplies when another application board is
connected to pins P1 and P2.
In this case, the 5 V and 3 V pins deliver a 5 V or 3 V power supply and the power
consumption must be lower than 100 mA.
•
5 V and 3 V can also be used as input power supply, e.g. when the USB connectors are
not connected to the PC.
In this case, the STM32F429 Discovery board must be powered by a power supply unit
or by auxiliary equipment complying with the standard EN-60950-1: 2006+A11/2009,
and must be Safety Extra Low Voltage (SELV) with limited power capability.
Note:
The board can also be powered through the USB USER connector and it is protected by D4
and D5 diodes when both USBs are connected (in this case the 5 V power is around
4.4 volts).
6.5 LEDs
•
LD1 COM:
The LD1 default status is red. LD1 turns to green to indicate that communications are in
progress between the PC and the ST-LINK/V2-B.
•
LD2 PWR:
The red LED indicates that the board is powered.
•
User LD3:
The green LED is a user LED connected to the I/O PG13 of the STM32F429ZIT6.
•
User LD4:
The red LED is a user LED connected to the I/O PG14 of the STM32F429ZIT6.
•
User LD5:
The green LED indicates when VBUS is present on CN6 and is connected to PB13 of
the STM32F429ZIT6.
•
User LD6:
The red LED indicates an overcurrent from VBUS of CN6 and is connected to the I/O
PC5 of the STM32F429ZIT6.
6.6 Push-buttons
•
B1 USER:
User and Wake-Up button connected to the I/O PA0 of the STM32F429ZIT6.
•
B2 RESET:
The push-button connected to NRST is used to RESET the STM32F429ZIT6.
