UM2032 Rev 3
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UM2032
Hardware layout and configuration
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5.3.2
STM32 power supply options
The 32F412GDISCOVERY offers the possibility to supply the STM32 under 2.0 V or 3.3 V.
A jumper must be placed in location 2.0 V of JP5 to supply the STM32 under 2.0 V, then
pins 2 and 3 are connected. Similarly the jumper must be placed in 3.3 V to supply the
STM32 with 3.3 V, then pins 1 and 2 of JP5 are connected.
For details on JP5 jumper setting refer to
Table 4: Power-supply-related jumper settings
.
5.3.3
Modification of STM32 voltage
Regulator U16 is dedicated to the 2.0 V supply. The output voltage of U16 is by default 2.0 V
but it is adjustable depending on the resistors R90 and R92 which are by default 120 and
68 ohms respectively. The output voltage is calculated as follows:
VOUT
VREF
1
R92
(
)
R90
(
)
÷
+
(
)
×
=
with VREF = 1.25 V.
If necessary, resistors R90 and R92 can be changed to modify the STM32 supply voltage.
R90 and R92 are easily located bottom side of the Discovery kit near U16 (see
and
Figure 8. R90 and R92 resistors
