STM32F429-Disco board power supply

[John Smith_2]

Posted on January 12, 2017 at 16:35

Hello!

I have a question about STM32F429-Disco evaluation board. As I see, LD3985 is used to supply the power to all on-board units (MCU, LCD, MEMS, SDRAM and others). But as it is written in LD3985  datasheet, it can provide only 150 mA output current. I think it's not enough for all these modules... How does this board work? =)

Thank you in advance!

#schematic #ld3985 #stm32f429-disco #evaluation-boards #power-supply

[Tesla DeLorean · Accepted solution]

Posted on January 12, 2017 at 17:47

Good question, the specification seems to suggest it can get north of 550mA and remain within 5% of regulation, but to be honest I've not checked on what the nominal loading is for all the components on the board, including the back-light.

http://www.mouser.com/ds/2/389/CD00003395-470441.pdf

 

[John Smith_2]

Posted on January 12, 2017 at 19:30

550 mA should be enough I think... But is it safely to use LD3985 in this mode for a long time (when it operates with peak current)?

[Tesla DeLorean]

Posted on January 12, 2017 at 20:17

I haven't analyzed the design, I doubt it is anywhere near 550mA, closer to 200mA I expect.

[John Smith_2]

Posted on January 12, 2017 at 21:14

Ok, thank you!