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TMS320F28P650SK: Power Consumption running Ethercat

Alex Paul
Expert 5715 points

Part Number: TMS320F28P650SK

Tool/software:

Hi experts,

How will the power consumption of the F28P65 be, when running an EtherCAT slave and some simple IO-Operations ? 


Kind regards,

Alex

  • 0
    TI__Mastermind 36526 points

    Hi,

    Please allow me a day or two to get back to you about this.

    Best Regards,

    Ben Collier

  • 0 in reply to Benjamin Collier
    TI__Expert 5715 points

    HI Benjamin,

    Ok thanks.

    Regards,
    Alex

  • 0 in reply to Alex Paul
    TI__Mastermind 36526 points

    Hi Alex,

    These are some rough numbers, but here is what I saw today:

    When running an EtherCAT example and communicating with our lab PC, I saw an average current consumption of ~410mA when applying 3.3V to our F28P65X launchpad.

    As a baseline, when running the blinky LED example on this launchpad, I saw only ~350mA of current drawn on the 3.3V rail.

    FYI, this launchpad has a 3.3V -> 1.2V LDO, so these current numbers include supplying power to the C28X core and they also include any inefficiency in the LDO. This number will also include power consumption for the PHYs. 

    Please let me know if you need any more data.

    Best Regards,

    Ben Collier

  • 0 in reply to Benjamin Collier
    TI__Expert 5715 points

    Hi Benjamin,

    This number seems to be quite high.

    Was this already containing the PHYs and other peripherals on the board ?  

    Do you think this number can be reduced?

    What would be the effect of using an external DC/DC  ?

    Regards,
    Alex

  • 0 in reply to Alex Paul
    TI__Mastermind 36526 points

    Hi, 

    Alex Paul said:
    What would be the effect of using an external DC/DC  ?

    Are you asking about the efficiency of the 3.3V -> 1.2V LDO? 

    I should be able to get you a lower estimate without all of the other ICs on the launchpad in another day or two.

    Best Regards,

    Ben Collier 

  • +1 in reply to Benjamin Collier
    TI__Mastermind 36526 points

    Alex,

    On a board that has no extra ICs, I measured .03A average when supplying 5V (uses two LDOs to generate 3.3V and 1.2V) and running a blinky LED example. This board does not have EtherCAT functionality, so I am not powering PHYs or anything unnecessary.

    In my experiment from last week, I saw a .165W increase in power consumption when running a EtherCAT example vs the blinky example. 

    I think it would be good to estimate that the MCU will draw (5V * .03A) + .165W = .315W when running an EtherCAT example. This includes both 3.3V and 1.2V rails.

    Best Regards,

    Ben Collier