STM32L476RG Nucleo Board

Fde W.1 · ‎2020-06-12

I was wondering if i were able to put 3.8V on the E5V power line. I checked in the User Manual and there is standing this at page 21:

E5V CN7 pin 6 4.75 V to 5.25 V 500 mA

When i look at the datasheet of the step down converter (LD39050):

There stands that the input voltage has a range of 1.5 to 5.5 V.

The question is: Can i put 3.8 V on the E5V line or does it have 4.75-5.25

Kind regards,

Frank de Wit

YS.K · ‎2020-06-12

The step-down converter (LD39050) is not capable of voltage multiplying.

but the LD39050 can produce 3.3V output with 3.8V input, maybe there will be no problem.

There are E5V and U5V voltage inputs on the board.

The circuit is configured to use the higher of the two voltages.

When you connect the USB cable to use the st-link,

the U5V voltage supply to the Nucleo-board from the PC USB 5V.

You can download a board schematic from the below link.

Resource -> Schematics

Fde W.1 · ‎2020-06-13

I am just wondering if it wont harm the board if i put 3.8 V at the E5V line to power the board.

I think that i wont be a problem because in the datasheet of the LD39050 stands that the range of input is 1.5 - 5.5V.

Only thing that made me doubt is that in the User manual of the Nucleo boards stands that this E5V pin needs 4.75 - 5.25.

YS.K · ‎2020-06-14

As far as I know, there is no problem with chip damage at a voltage lower than the chip specification.

Fde W.1 · ‎2020-06-17

Thank you for your answer!