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MSP-EXP430FR5994: Problems in powering the MSP430FR5994 From battery

Part Number: MSP-EXP430FR5994
Other Parts Discussed in Thread: MSP430FR5994

Hi all

I am using MSP430FR5994 launchpad for my project at IICDC 2017, and i want to power it by battery

I read the Datasheet which says its compatible with 3.6v

So i have a doubt, if input max is 3.6 volts then how we get 5 volts at pin in MSP430

Also could you please help me with the other precautions i should take if i am planning to use rechargeable li-ion battery to drive it

  • Hi Prakhar,

    The MSP430FR5994 launchpad converts the 5v USB to 3.3v as part of the eZ-FET circuit that provides the programming capability.

    There is a set of jumpers that connect the power, programming and communications signals between the eZ-FET circuit and the MSP430FR5994.

    You will need to remove the +3V3 jumper to isolate the power from the eZ-FET circuit, then connect your battery to one of the several +3V3 connection points on the PCB.

    There is also a super capacitor on the launchpad and you will have to remove it's jumper as well.

    Now regarding the maximum operating voltage, it is advised not to exceed 3.6v.  You will be cutting it close as a typical lithium battery can be 3.7v or 4.2v.

    In either case you could put a shottkey diode in series from the battery to the +3v3 on the launchpad. This should provide a 0.3v drop (depending on the current drawn from the battery) lowering the operating voltage closer to  +3.6v.  

    With that said, if this is just for your project, you can try operating at up to +3.9v without probably doing any damage to the device.  The risk is up to you.

  • Thanks for replying

    Sir,

    I am powering the MSP from series of two 1.5v pencil cells

    and remove the 3.43v jtag from FET connection and inserted the 3.02 V output from battery to J5 Header pin 3.3v and ground

    But now also i am unable to "ON" my MSP430

    Also if i am powering msp430 by a battery of 3.0 volts , i would not be able to extract 5V from msp430, so any alternative or solution for this problem? asi need VCC of 5volt for different sensors in my project

  • Hi Prakhar,

    Check the users guide section 2.3 to make sure you have the connections correct.

    As long as you remove the +3.3v jumper on the J101 connector as shown in the users guide, section 2.3, you can also have USB cable connected the launchpad to generate the +5v.

    To help me understand, if you connect the batteries the MSP430 is not operating but it operates normally when the jumpers are installed?

  • Hello Prakhar,

    Haven't heard back from you in some time so I will assume you have resolved your issue.

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