Running STM32f4 Discovery Board from a DC voltage (Beginners question)

[titkin]

Posted on January 18, 2014 at 21:28

Hello,

My project is to drive some SPI external sensor with 3.3V and read its data. Since this sensor consumes a higher current that a single I/O can supply I intend to drive this sensor using 3.7V battery.As noted in STM32f4 Discovery Board datasheet the board requires a 5V power supply.After all I am intrested to operate all the project (Board +sensor) from a single voltage level battery/batteries. Could it be a 3.7V battery  (<5V)? Or may be 7.4V (two batteries in a series) is better (>5V)?Thank you!Tal #!bug

[Tesla DeLorean]

Posted on January 19, 2014 at 09:58

The board itself runs at 3.0V, you'd want to consult the specification of the regulator to understand it's drop out voltage, and maximum input limits.

http://www.st.com/web/en/resource/technical/document/datasheet/CD00003395.pdf

That would be a 3.3V device, but I'm pretty sure the design runs at 3.0V, get a scope or multi-meter and confirm. The max voltage input is 6V, so two batteries probably not going to work with this one. As I recall the designs I've used with 3.7V lithium batteries we ran the STM32 at 2.7 or 2.8V Edit: Nevermind the

http://www.stm32circle.com/resources/Datasheets/BAT60J.pdf

explains the 300 mV drop, the drop out on the regulator is about 1/10th of that