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power consumption of microcontrollers

Discussion in 'Microcontrollers' started by elecLear78, Jun 27, 2017.

  1. elecLear78

    elecLear78 Member

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    I wanted to know if i am operating at higher MIPS i consume more power and if i operate at lower MIPS i consume lower power? In general i am asking for micro controllers and in particular to micro chip. if the above step is true then what is the ideal MIPS i should be working at? Please advise.
     
  2. Nigel Goodwin

    Nigel Goodwin Super Moderator Most Helpful Member

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    Yes, the higher the clock speed the higher the current consumption.

    There is no 'ideal' clock frequency, it depends entirely on the exact circumstances that you're using it for.

    PIC's do very often allow you to change the speed during program execution, so you can set maximum speed where it's needed, and slow it down where it's not.
     
  3. DirtyLude

    DirtyLude Well-Known Member

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    Sleep modes are your friend. Generally you want to put the chip into the lowest level of sleep possible depending on your requirements for wake up while you aren't doing anything. You also want to clock as slow as possible to complete your tasks within whatever timeline you have. As Nigel said, if you want to go that far, you can adjust clock speed on the fly. I do this on a project with an LCD. Clock as fast as possible to clear or write to the LCD so the LCD doesn't lag, and clock slower when working with other peripherals like the radio.

    Someone did the math a while ago about doing everything as quickly as possible and sleeping, or clocking slowly and sleeping and the clocking slowly won out. Not an EE and the math hurts my head, so no details unfortunately.

    Generally newer chips have ridiculously low power requirements if you spend a bit of time dropping into sleep or even complete shut down any time you aren't processing.
     
  4. dave

    Dave New Member

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  5. elecLear78

    elecLear78 Member

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    But i am just guessing i don't have exact details. The difference will be some milli amps i suppose. Will it be a great deal?
     
  6. OBW0549

    OBW0549 Member

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    Yes.

    PIC data sheets specify power consumption at various clock rates. Look in the Electrical Characteristics section.

    That question is impossible to answer, other than to say that if you are trying to keep power consumption to a minimum you need to operate the chip as fast as your application requires, but no faster.

    READ THE DATA SHEET.
     
  7. Nigel Goodwin

    Nigel Goodwin Super Moderator Most Helpful Member

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    Yes, speed makes a huge difference to consumption - 100's of percent.
     

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