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MSP432E401Y: Any way to disable the +5/+3.3V output pins on the MSP432P401R Boards?

Part Number: MSP432E401Y

(Sorry for the mismatched part number. I wasn't getting any results when searching for the MSP432P401R.)

Hello,

I was wondering if there was any way that I could disable the +5 and +3.3V output pins on the MSP432P401R boards.

I am working on a wireless IoT solution which requires saving as much power as possible. I currently have a signal conditioning board being powered by the +5V pin of the 432 and an accelerometer being powered by the +3.3V pin. I noticed when the MSP432 enters LPM3.5 that these pins are still powering everything. I have been using the MSP432 SDK for things like Timer32 and LPM, but I haven't had any luck finding software solutions in the SDK for this problem. However, I'm fairly new to development on the 432s, and I acknowledge that I might be misunderstanding this problem entirely.

Any suggestions for software or hardware solutions would be helpful.

Thanks,

Greg

  • Hi Greg,

    They can't be turned off via software, but if you're wanting to turn off the connections you have with those pins I have a potential idea. If you're using these rails to power the device you could potentially toggle a switch / fet to power off these devices. If you run a GPIO pin high to turn the FET on then when you go into LPM3.5 you can toggle the FET off with that GPIO. 

    You can also disconnect these lines from the MSP432P401R itself by removing the jumper pins, but that won't solve your issue. Those rails are actually sourced from the XDS110-ET isolation block.

    Regards,

    Luke

  • Hello Luke,

    Thank you for the insight! I will give that hardware solution a shot. 

    Greg