STMicroelectronics B-G474E-DPOW1, Manual

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10.2 Power source selection
The B-G474E-DPOW1 product is designed to be powered by a 5 V DC power supply. It is possible to configure
the Discovery board with JP5 header to use any of the four sources described in
Table 6 for the 5 V DC power
supply.
Table 6. JP5 5V_SEL configuration
Reference Jumper (1) Function Comment
JP5
STLK
5 V is supplied from USB STLK
CN3
• 5 V (+/- 5 %),
• 700 mA embedded overcurrent protection
• Up to 500 mA capable
CHGR
5 V is supplied from USB STLK
CN3
• 5 V (+/- 5 %)
• No embedded current protection
• Up to 1.5 A current
USBC
5 V is supplied from LTC3114-1
5 V converter (Power source
connected to USB Type-C
®
CN2
connector)
• 5 V (+/- 3 %)
• Embedded selectable current protection:
–
Up to 950 mA on 5 V
– Up to 1.5 A from USB Type-C
®
V
BUS
• USB Type-C
®
V
BUS
nominal voltage from 5 V
to 15 V
E5V
5 V is supplied from 5V_I pin of
CN9 extension connector
• 5 V (+/- 5 %)
• No embedded current protection
• Up to 1.5 A current
1. The default setting is in bold
In all below four power sources configuration, the LED LD7 5V and LED LD6 3V3 must be lit when the B-G474E-
DPOW1 product is correctly powered by the 5 V.
10.2.1 STLK
Figure 12 shows the selection of 5V from STLK on JP5, with a power source connected to USB ST-LINK (CN3). It
is the default setting.
The CN3 ST-LINK USB connector (STLK) can power the B-G474E-DPOW1 Discovery kit, but the host PC only
provides 100 mA to the ST-LINK circuit until the end of USB enumeration. At the end of the USB enumeration, the
B-G474E-DPOW1 Discovery kit asks for 500 mA current to the host PC.
If the USB enumeration succeeds, a power switch STMPS2151STR powers the board with up to 500mA current.
This power switch also features a 700 mA current limitation to protect the PC in case of overcurrent on the board.
Note: In this mode, in case a wall charger powers the board, there is no USB enumeration. Therefore, the COM LED
LD9 remains OFF permanently, but the 700 mA protection is still active on the powered board.
Figure 12. JP5 (STLK) from CN3 (USB STLK)
UM2577
Power source selection
UM2577 - Rev 2
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