UM1871 datasheet(11/64 Pages) STMICROELECTRONICS

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UM1871

Hardware layout and configuration

2.2

Power supply

STM32446E-EVAL evaluation board is designed to be powered by 5 V DC power supply

and to be protected by PolyZen from wrong power plug-in event. It is possible to configure

the evaluation board to use any of the following five sources for the power supply:

•

5 V DC power adapter connected to CN20 (PSU on silkscreen), the Power Jack on the

board. The external power supply is not provided with the board.

•

5 V DC power with 500 mA limitation from CN9, the USB_OTG_FS Micro-AB

connector

•

5 V DC power with 500 mA limitation from CN8, the USB_OTG_HS Micro-AB

connector

•

5 V DC power with 300 mA limitation from CN16, the ST-LINK/V2 USB

•

5 V DC power from both CN10 and CN12, the extension connector for daughterboard

In case the boards is powered by an external 5V power supply connected to CN20 or CN10

and CN12, this power source must comply with the standard EN-60950-1: 2006+A11/2009,

and must be Safety Extra Low Voltage (SELV) with limited power capability.

The power supply is configured using JP12, JP21 and JP9 as described in Table 2: 32 KHz

crystal Y2 related solder bridges.

Table 1. Power related jumpers and solder bridges

Jumper

Description

JP12

MCU_VDD is connected to 3.3 V power when JP12 is closed and MCU current

consumption measurement can be done manually by multi-meter when JP12 is open.

Default setting: Fitted.

JP21

To select the ST-LINK/V2-1 USB connector (CN16) power supply, set JP21 on U5V

position as shown (default setting):

To select power supply jack (CN20 PSU) power supply, set JP21 on PSU as shown:

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