• State TI Thinks Resolved
  • Locked Locked
  • Replies 5 replies
  • Answers 1 answer
  • Subscribers 80 subscribers
  • Views 1393 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.

Original question:

MSP432P401R: Externally Powering LaunchPad

MSP432P401R: Externally Powering launchpad no usb

Carlos Ramirez
Prodigy 10 points

Part Number: MSP432P401R

Hello,

So I'm doing a project which involves using a 12V battery source, I have a voltage regulator which steps down to 5V and I'm trying to feed those 5V to the MSP432P401R launchpad externally not with the usb. I also need to design a PCB for this project and place the voltage regulator on the pcb feeding the 5V to the launchpad, so my question is how can I do this? How can I power the launchpad from the OUT+ and OUT- of the regulator to the launchpad? I was thinking that maybe disconnecting the jumpers on J101, and feeding the 5V and GND pins but I'm not very sure and don't want to mess up the launchpad if that's not the way to go.

Another question, I have some components connected to the launchpad which need 5V, for this am I required to feed 5V to the launchpad? or can I supply 3.3V and just get the 5V from the pins?

Thanks,

Carlos

  • 0
    TI__Guru 70241 points
    Hi Carlos,

    the MSP432 requires 3.3 V (1.8V - 3.6V are the allowed operating range). So you can not run it directly from the 5V. So for this you need another voltage regulator (LDO, DCDC) to get your 5V down to the 3.3V.

    As in interim solution you could use the LDO do the debugger part of the launchpad but you need to ensure that you do not connect the USB of the debugger at the same time you have connected your 5V.

    Therefore i recommend to add a 3.3V LDO to your circuit and connect this the the (3.3V) of the Launchpad headers with removing the 3V3 marked jumper which connects the device with the debugger circuit.

    Note: the Launchpad has not the capabilities to generate 5V out of the 3.3V.

    Regards,
    Stefan
  • 0 in reply to Stefan Schauer
    Guru 44185 points
    Stefan:
    It is pretty obvious that the Launchpad *can* change 5 V to 3.3 since the USB power is 5 V. The problem is that the 3.3 V regulator is on the "XDS-110" side and the regulator is isolated when you pull the jumpers.

    I wish there was a jumper that would let you connect the LDO to the 5 V line on the launchpad, but there is not.
  • 0 in reply to Keith Barkley
    TI__Guru 70241 points
    Hi Keith,
    i see your point but as supply is very different for most of the applications the decision was to not put this on the application area but have it on the debugger only, esp. as it also affects the current measurement logic.

    Nevertheless there is a jumper which connects the 5V of the Launchpad to the LDO (it is the 5V Jumper) - see schematic.
    The negative side effect is of course that it fully powers also the debugger and if powered from there could have conflicts if an USB is connected.

    Regards,
    Stefan
  • 0 in reply to Stefan Schauer
    TI__Guru 70241 points
    Hi Carlos,

    do you have further questions regarding this topic? If not, please select "Resolved" for the post that solved your issue so this thread can be closed out. If you have a different question, please select "Ask a related question" or " Ask a new question".
    Thanks a lot!

    Best regards,
    Stefan
  • 0 in reply to Stefan Schauer
    TI__Guru 70241 points
    Hi Carlos,

    I suppose that you were able to move on with your application as you didn't reply anymore, so I'll close this post.
    Please feel free to comment again if you look for further assistance regarding this topic, it will re-open the thread. If you have a different question, please select "Ask a related question" or " Ask a new question".

    Best regards,
    Stefan

**Attention** This is a public forum