Maximum input current in VBUS for the TM4C123GH6PM board

Javier Martinez

Other Parts Discussed in Thread: TM4C123GH6PM

Hi all,

I have a circuit that I am designing and I need the use of a 7805 (1.5 A) voltage regulator for a led strip. The thing is, I was wondering the maximum input current at the VBUS so as to know if I have to use another regulator with less current at the output. Does anyone know that data? Because I have been looking in the datasheet without any success.

Thanks,

Javier

over 9 years ago

0 Robert Adsett72 over 9 years ago

Guru 10570 points

Isn't VBUS already 5V nominal? A 7805 (or even an LDO) would be worse than useless in that case.

Robert

There's also an open question as to whether you would have 1.5A available on a USB connection

0 Javier Martinez over 9 years ago in reply to Robert Adsett72

Prodigy 70 points

I wouldn't use any of the USBs to power on the board, using instead the voltage regulator, that's why I am asking about the current

0 Robert Adsett72 over 9 years ago in reply to Javier Martinez

Guru 10570 points

Then I don't understand the question. The current limit will be whatever your supplies limit is. And VBUS is limited to 5V since anything more will damage the IC so the objection to a linear regulator still stands. Also why would you use VBUS if you are not using USB?

Robert

0 Robert Adsett72 over 9 years ago in reply to Javier Martinez

Guru 10570 points

Also you haven't mentioned what board you are using

Robert

0 Javier Martinez over 9 years ago in reply to Robert Adsett72

Prodigy 70 points

This is a basic schematic of how I would do it. As far as I'm concerned, if not powered using USB, then I have to power it using VBUS so as to assure that the voltage that the microcontroller receives is the proper one. My concern is that if the current is too much so I would need to use another regulator

0 Javier Martinez over 9 years ago in reply to Robert Adsett72

Prodigy 70 points

A TM4C123GH6PM

0 Robert Adsett72 over 9 years ago in reply to Javier Martinez

Guru 10570 points

That's an IC not a board. Do you just mean the IC?

Robert

0 Amit Ashara over 9 years ago in reply to Javier Martinez

TI__Guru**** 244400 points

Hello Javier,

The microcontroller requires 3.3V and not 5V as shown in the schematic block diagram. You would need a 5V to 3.3V LDO.

Arm-based microcontrollers

Arm-based microcontrollers forum

Maximum input current in VBUS for the TM4C123GH6PM board