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MSP430F5437A: what are the best practices to consume least current in LPM3 apart from what we did now as below?

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Replies: 4

Views: 68

Part Number: MSP430F5437A

Hi,

Currently we have done

1) All ports made as Digital input with pullup or pull down enabled.

2) Left Unified Clock System and Voltage core in the recent settings before going to LPM3

3) RTC is running in counter mode with interrupt enabled to wake up after some time.

4) No other internal modules like I2C,ADC, etc. are running/enabled.

Please let us know whether there are any other measures we can take to reduce current consumption in LPM3 mode.

Thanks,

Ayyappan M.

  • Hi,

    So which current draw do you see in LPM3 now?

    Is it reasonable comparing to datasheet limits?

    Best regards

    Lukas

  • In reply to Lukas Badura:

    Hi Lukas,

    Currently the board with microcontroller consumes 750 micro Amps.

    Most of the interfaces running with the same power were isolated.

    Still we are analyzing to isolate from power consumption.

    At the stage of my previous post it consumed 850 micro amps.

    After making all the available ADC pins as Analog inputs instead of Digital input with internal pulldown enabled,

    100 micro amps reduced further to 750 micro amps.

    From the page 414 of user manual, we understand that each I/O can be set to input high impedance, input with pulldown, input with pullup, output high (low or high drive strength), or output low (low or high drive strength). But there is no setting available to configure all the pins as input high impedance. It would be of great help if you could share the work around to set all the I/O port as input high impedance or any other steps to reduce power consumption in LPM3

    Thanks,

    Ayyappan M

  • In reply to Ayyappan Muthukrishnan:

    So the device itself consumes in the range of some uA in LPM3, depending on temperature Vcore and VCC.

    So you are far away from these numbers.

    What else is on your board what could explain the high current draw?

    Now if I understand correct you would like to set all pins to input high impedance?

    You can check the code examples from web, in this case it's set to output low

      P1OUT = 0x00;
      P2OUT = 0x00;
      P3OUT = 0x00;
      P4OUT = 0x00;
      P5OUT = 0x00;
      P6OUT = 0x00;
      P7OUT = 0x00;
      P8OUT = 0x00;
      P9OUT = 0x00;
      P10OUT = 0x00;
      P11OUT = 0x00;
      PJOUT = 0x00;

      P1DIR = 0xFF;
      P2DIR = 0xFF;
      P3DIR = 0xFF;
      P4DIR = 0xFF;
      P5DIR = 0xFF;
      P6DIR = 0xFF;
      P7DIR = 0xFF;
      P8DIR = 0xFF;
      P9DIR = 0xFF;
      P10DIR = 0xFF;
      P11DIR = 0xFF;
      PJDIR = 0xFF;

    Does this answer your question?

  • In reply to Lukas Badura:

    Can we mark this topic as resolved or do you have any further questions?

    Lukas

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