NUCLEO-H743ZI board LD39050PU33R

KevinA · ‎2018-03-10

Posted on March 10, 2018 at 21:40

On the NUCLEO-H743ZI board the LD39050PU33R 3.3 volt LDO provides voltage but what is the Vd or Vdrop for the LD39050PU33R?

I found I can add 3.7 volt (18650 battery) to JP3 pin 3 : I can't use VBAT as it is wired to 3.3 volts.

Object, run board on battery!

Thanks...

#nucleo-h743zi

Tesla DeLorean · ‎2018-03-10

Posted on March 10, 2018 at 22:32

Data Sheet says 200mV

http://www.st.com/content/ccc/resource/technical/document/datasheet/12/43/cc/93/21/f6/41/66/CD00227527.pdf/files/CD00227527.pdf/jcr:content/translations/en.CD00227527.pdf

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T J · ‎2018-03-10

Posted on March 11, 2018 at 00:46

I use this one, AP2114H-3.3TRG1, it is the same PNP type regulator, but will drive upto 1.4A ( probably only because it can remove the heat easier..)

dropout voltage under 0.2V at 400mA

https://www.digikey.com/product-detail/en/diodes-incorporated/AP2114H-3.3TRG1/AP2114H-3.3TRG1DITR-ND/4470756

KevinA · ‎2018-03-10

Posted on March 11, 2018 at 03:01

I'm use to the .7 drop from years ago, after reading about the device I'm hooking to 'Supply voltage range: 3.0V~ 4.3V, Typ: 3.8V' I'm going to us a STM32L452 at 1.8 volt to control the CAT-M1 device (it's I/O is 1.8 V) with a solar powered Lipo at 3.7 volt. DigiKeys price was impressive at $399, a few more than needed... Mouser has 1 @ pricing, $0.36.

I'm waiting on a NUCLEO-L452RE-P I ordered yesterday for power testing.. The

NUCLEO-H743ZI

was using .18 amp and I expect the NUCLEO-L452RE-P to be around 10 times less or about .08 amp - without the ST-Link part the current will drop it more.