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LAUNCHXL-F28P65X: Abnormal high temp

Zoey Wu
Expert 6005 points
Part Number: LAUNCHXL-F28P65X


Tool/software:

Hi team

my customer is using F28P65 and they found that when they run with their own software, the temp will raise to 70 degree centigrade in a 25 degree centigrade environment. They are using the external LDO and 6 layers PCB with power and GND layer following the EVM layout.

The board will be put into the control cabinet and the temp will rise to 100 degree centigrade . The worst environment will be up to 50 degree centigrade and they are afraid that the temp of the chip will rise above 125 degree. Do u think it is a high risk?

the hardware is no problem because the system can work well.

i have also let them to test the EVM board with their own software running.  It is surprising to find that the chip will rise up to 160 degree centigrade. do u think it makes sense? 

could u kindly give some advise?thanks 

  • 0
    TI__Mastermind 24430 points

    Hello,

    A few initial questions:

    1. Can you confirm that the temperature rise is seen both using a custom PCB as well as on a TI EVM?
    2. How is the customer measuring the temperature in both cases?
    3. Can I ask what customer this is for?

    Best Regards,

    Allison

  • 0 in reply to Allison Nguyen
    TI__Expert 6005 points

    Hi Allison,

    1. Yes;

    2 when the board is put into the control cabinet, they use a temp sensor around the chip to read the temp; and in other cases, they use thermal camera to read the temp ;

    3 the customer is a robot customer used in servo drive. 

  • 0 in reply to Zoey Wu
    TI__Mastermind 24430 points

    Hi Zoey,

    Thanks for the response. Let me forward this to a our expert on temp sensor to see if they can address this inquiry.

    Best Regards,

    Allison

  • 0 in reply to Allison Nguyen
    TI__Mastermind 38920 points

    Zoey,

    Please help gather below information to help us understand where the temp rise may be coming from:

    1.) What is the part number used, and package type?  How many processors are running, CLA, CPU1 CPU2 and is lockstep enabled?

    2.) What is the clock setting, specifically SYSCLK?  Is device running at max 200MHz SYSCLK?

    3.)  Is VREG enabled or disabled in the application?

    4.) What are the peripherals running in the application?

    6.) Are there device peripheral IOs that are actively switching, IOs toggling, EPWM pins toggling?

    7.) Possible to measure 3.3V and 1.2V currents?  From your response above, it looks like temp rise is also occurring in TI EVM (i'm assuming launchpad).  You can measure current indirectly in the launchpad by measuring the voltages across L1 and L3.  See schematic below:

    Looking at F28P65x package thermals, NMR 169 has the worse thermal resistance (junction-to air) at 29.2degC/Watt.  Reason for asking the information above is to understand how much power the device is consuming.  Hard to tell how 25C to 70C rise (45C rise).  This means that the device is consuming around 1.5Watts to account for the increase.

    Regards,

    Joseph

  • 0 in reply to Joseph Casuga
    TI__Mastermind 38920 points

    Hi Zoey,

    Marking this closed as this is being worked on separately by systems application team through emails.

    Regards,

    joseph