DocID028183 Rev 1
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UM1932
Hardware layout and configuration
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required power, the enumeration finishes by a “SetConfiguration” command and then, the
power switch ST890 U4 is switched ON, the red LED LD5 is turned ON, thus the board can
consume no more than 500mA. If the host is not able to provide such requested current, the
enumeration fails. Therefore the ST890 U4 remains OFF and the board will not be powered.
As a consequence the red LED LD5 remains turned OFF. In this case it is mandatory to use
another power supply source.
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 jumper in JP2 header in E5V position.
2.
Connect an external power source to VIN pin 8 of Arduino connector CN6.
3.
Check the red LED LD5 is turned on.
4.
Connect host PC to USB connector CN1.
The ST890 power switch protects the USB port of the host against current demand
exceeding 600 mA, should a short-circuit occur on the board.
The STM32F469I-DISCO board can also be supplied from a USB power source not
supporting enumeration, such as a USB charger. In this particular case, the solder bridge
SB16 should be closed. ST-LINK/V2-1 turns the ST890 power switch U4 ON regardless of
enumeration procedure result and passes the power unconditionally to the board.
5.2.3 Measurement
of
current
IDD drawn by the STM32F469NI
The jumper JP5 should be closed (default) to supply the STM32F469NI MCU. To measure
the current IDD drawn by the microcontroller STM32F469NIH6 only, remove the jumper JP5
and replace it by a multimeter.
5.2.4
Power related jumpers
The power supply is configured by setting the related jumpers
JP2, JP5 and solder bridge
SB8
as described in
Table 1: Power related jumpers
.
Table 1. Power related jumpers
Jumper,
Solder bridge
Description
JP5
JP5 IDD is used to measure STM32 current consumption manually by multimeter.
Default setting
: Closed by a jumper
SB8
By default SB8 is closed to power +3V3 from regulator U7.
If the board is powered by the pin 1 of extension connector CN12 or by the pin 4 of
the Arduino connector CN6, it is mandatory to open SB8 to avoid reverse current
injection in regulator U7.
(Default setting):
SB8 closed
