UM2032 datasheet(13/48 Pages) STMICROELECTRONICS

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UM2032

Hardware layout and configuration

area. A jumper should be placed in location E5V of jumper JP3, connecting pin 1 to pin

2 of JP3. The green LED LD6 is lighted on to confirm the presence of +5 V voltage.

•

5 V DC from +5 V pin of Arduino Uno V3 connector (CN2 pin 5) with limitations. The

jumpers on JP3 and CN5 have to be removed, SB21 (NRST) and SB28 (SWO) have to

be opened. In such configuration the ST-LINK/V2-1 MCU is not powered, as

consequence the 8 MHz of the ST-LINK/V2-1 cannot be used as external input clock

for the STM32.

For details on JP3 jumper setting refer to Table 2: Power-supply-related jumper settings.

6.3.2

STM32 power supply options

The 32F412GDISCOVERY offers the possibility to supply the STM32 under 2.0 V or 3.3 V.

A jumper has to 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 has to 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 2: Power-supply-related jumper settings.

6.3.3

Modification of STM32 voltage

Regulator U16 LD1117STR 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 following:

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 Figure 5 and

Figure 8).

VOUT

VREF

R92

()

R90

()

UM2032 Datasheet(PDF) 13 Page - STMicroelectronics