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EK-TM4C123GXL: TM4C123GXL custom booster pack design questions

Wojciech Pope
Prodigy 20 points
Part Number: EK-TM4C123GXL

Hello,

as a project for electronics course I'd like to design a custom IoT Booster Pack for my TM4C board. The board will be composed of several sensors, LCD/E-Ink display (optional) and a socket for NodeMCU. I'd like to power the boards from external 5V source that would be connected to VBUS on TM4C board and a LDO on the Booster Pack.

1. I'd like to ask if I could design the power supply circuit in such a way (is it viable/will it cause any problems?).

2. Also, do I have to add some kind of isolation between the boards? Or can I connect the microcontroller pins to sensor/display/NodeMCU pins without isolation?

I added simple concept schematic for reference.

  • 0
    TI__Guru*** 135355 points
    Hello Wojciech,

    I see no issue with the way you have this setup, but I am not sure why you wouldn't just pull straight from the 3.3V line when you need to use 3.3V. That seems to be an unnecessary complication you are adding in unless you actually need the 5V for something else.

    You don't need to do any isolation for a simple application like this BoosterPack.
  • 0 in reply to Ralph Jacobi
    Prodigy 20 points

    Thank you for your response.

    I don't want to power my board from the 123GXL since I think the current it provides might not be sufficient. Also, I'd like the board to be able to work standalone. I would be able then to power other microcontrollers or add more sensors through external pins. On the other hand I was not sure if I could connect the ADM7171 3.3V line to 123GXL 3.3V line without causing trouble with the on board LDO.

  • 0 in reply to Wojciech Pope
    TI__Guru*** 135355 points
    Hello Wojciech,

    The +3.3V rail is supplied via a 400mA regulator.

    If you are supplying the BoosterPack with another power source, you wouldn't want to then connect the power rails on the BoosterPack to the TM4C supplies, so you may not want that connection as a whole.