• State
  • Locked Locked
  • Replies 3 replies
  • Subscribers 32 subscribers
  • Views 368 views
  • Users 0 members are here
Support feedback
Options
Options
Related

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

Power Supply requirement for TM4C12433H6PM

Ming Chun Paul Lee
Prodigy 130 points

Hi,

I am trying to include this controller to my system PCB for some digital control.  After looking through the datasheet, it mentions it needs 3.3V supply for IO pads.  And for pin25 and pin56, it says this is a 1.2V for the core, however, it mentions that this is supplied from an internal LDO.  My question is, does that mean I dont need to supply externally for this 1.2V?

Also, if I dont need to use the on-chip ADC, does that mean I dont need to supply additional 3.3V analog?

How about the current consumption I am expecting for this device? (I want to make sure the LDO I am going to pick and support the max load of this device)

Thanks

  • 0
    Guru 27665 points

    Ming Chun Paul Lee said:
    And for pin25 and pin56, it says this is a 1.2V for the core, however, it mentions that this is supplied from an internal LDO.  My question is, does that mean I dont need to supply externally for this 1.2V?

    Yes, although you will need a bulk capacitor for the supply.  The 1V2 is brought out to an external pin for decoupling.

    Ming Chun Paul Lee said:
    Also, if I dont need to use the on-chip ADC, does that mean I dont need to supply additional 3.3V analog?

    I'd supply it in any case. Even if TI assured me I could leave it floating. I doubt you can leave it floating though, the power-on reset monitors VDDA.

    Ming Chun Paul Lee said:
    How about the current consumption I am expecting for this device? (I want to make sure the LDO I am going to pick and support the max load of this device)

    You should check under electrical characteristics of the data sheet (current consumption). It's quite detailed. Remember to include the LDO inrush in your considerations. It's momentary but it may cause you to pick a slightly larger device.

    Robert

  • 0 in reply to Robert Adsett
    Guru 20670 points
    Just 1 note - I do believe in the datasheet it's advised to have the ADC powered (through VDDA and GNDA )even when you don't use the ADC. So I would follow Robert's advise in never leave it floating.
  • 0 in reply to Robert Adsett
    TI__Guru**** 244400 points
    Hello Ming,

    Thanks Robert. You did answer all of them, but to emphasize.

    1. A bulk and bypass capacitor both are needed. Typically a 2.2 in parallel with 1.0 and 0.1 should take care of the requirement.
    2. VDDA is "required"
    3. If the LDO is being used only for TM4C (not for anything else) a TPS73733DRV is sufficient for 5V to 3.3V.

    Regards
    Amit