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TMS320F28377S: Internal Temperature Sensor Resolution

Peter Berger
Prodigy 210 points
Part Number: TMS320F28377S


Hi,

I looked through the TRM and datasheet for this MCU and couldn't find the Resolution value of the Internal Temperature Sensor (i did find accuracy in the datasheet)

could you please specify what it is.

P.S

To prevent misunderstanding i define "Resolution" as the the smallest detectable change by the component.

Thanks and Best Regards,

Peter Berger

  • 0
    TI__Guru 60865 points
    Hi Peter,

    The nominal sensitivity is around 4mV/deg. C.

    The sensor itself is analog in nature, so the minimum resolvable difference is more on the ADC being used to sense the sensor.

    Assuming a 2.5V reference voltage, each LSB is about 610uV so the nominal resolution is about 0.61mV/4mV = 0.1525 deg. C. You can resolve further differences if you heavily oversample and average.

    For worst case (not spec'ed in the DS, but should give you some idea) you can use 3.75mV / deg. C, 3.0V reference range, and use the INL of the ADC as the limiting factor instead of the LSB size. This will give you 2 LSBs INL*(3.0V/4096) / (.00375) = 0.4 deg. C. Maybe round up to 0.5 degree C for a nice round easy number.

    Note that this doesn't consider noise; I'm not sure how much you'd need to average in order to consistently resolve 0.5 degrees C.
  • 0
    TI__Mastermind 28275 points
    Hi Peter,

    Do you have any more questions on this?
  • 0
    TI__Mastermind 28275 points
    Hi Peter,

    I'm assuming your question was adequately answered so will be closing this thread. If that's not the case, feel free to reply to this thread or create a new one if this one locks out due to inactivity.