Jedidiah oyeyemi

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10 years ago.

External power supply problems Vbat and 9v power battery

i plugged a new 9v battery but all i see is the ld1 light flashing in red and ld3 has a sold red light the stm also seems to have overheated the chip and fried it, but i really need to know because i need to make something that is standalone and not hooked into the computer

Question relating to:

Last updated: 20 Apr 2021
Affordable and flexible platform to ease prototyping using a STM32F401RET6 microcontroller.

well it seems vbat has completely fried my board programs only upload halfway

posted by Jedidiah oyeyemi 16 Apr 2014

1 Answer

Wim Huiskamp
10 years ago.

Very likely that the F401 is fried. The VBAT pin is only for backup of the real-time clock. VBAT should be between 1.65V and 3.6V according to the datasheet. In the nucleo the VBAT pin is also connected to VDD (3V3) through SB45. That means you have applied 9V to the 3V3 powersupply of the F401 ==> deadly force...

You should be able to supply external (battery) power through the Vin pin. Voltage range is between 5V and 9V.

Accepted Answer

yeah thanks i looked at the instruction mannual more and found that i had to move jumper pints to switch power supplies but not before i fried the board the only upside is that is not expensive like the arduinos.

posted by Jedidiah oyeyemi 17 Apr 2014

According to page 16 of user manual UM1724 for Nucleo Boards, voltage range for VIN is 7-12V not like on infographic 5-9V. Which info is wrong?

posted by Wojciech Sojka 14 Aug 2014