UM2033 Rev 4
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UM2033
Hardware layout and configuration
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5 V DC power charger connected to USB ST-LINK (CN16). In this case, if the
32F769IDISCOVERY Discovery board is powered by an external USB charger then
the debug features are not available. If the board is connected to the PC instead, the
limitation is no more effective with a high risk to damage the PC (5 V power source on
the chgr silkscreen of CN3). Refer to
Figure 11. chgr (CN3)
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48 V DC power from RJ45 Ethernet connector (CN10). In this case, the on-board
module PoE (Power over Ethernet) generates the 5 V and it can provide up to 600 mA.
This module is a Powered Device complying with the standard IEEE802.3af, class 1 /
2. The external power supply must be fully IEEE 802.3af compliant (5 V power source
on the poe5V silkscreen of CN3). Refer to
Figure 12. poe5V (CN3)
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5 V DC power with limitation from CN16, the USB type Micro-B connector of
ST-LINK/V2-1 (USB 5 V power source on the stlk silkscreen of CN3). It is the default
setting. If the USB enumeration succeeds (as explained below), the ST-LINK 5 V link
power is enabled, by asserting the PWR_ENn signal. This pin is connected to a power
switch ST890, which powers the board. This power switch also features a current
limitation to protect the PC in case of a short-circuit on the board (more than 700 mA).
Refer to
The 32F769IDISCOVERY Discovery board can be powered from the stlk ST-LINK USB
connector (CN16), but only the ST-LINK circuit has the power before the USB enumeration
because the host PC only provides 100 mA to the board at that time. During the USB
enumeration, the 32F769IDISCOVERY Discovery board asks for 500 mA of current to the
host PC. If the host can provide the required power, the enumeration finishes by a
SetConfiguration
command, and then, the power transistor ST890 is switched ON, the red
