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TMP441 remote temperature read always 0xC0

Other Parts Discussed in Thread: TMP441

Hi Team,

I am using TMP441, When i try to read the remote temperature i am always getting 0xC0.

I kept the default configuration for all the register.

Thanks!

Thamizh

  • Hi Thamizh,

     

    Were you able to read the local temperature? If you were, it is a good indication that the device setup is correct and you are able to communicate with the device. Then you may concentrate on the remote diode. Make sure recommendation on page #8 of the datasheet is followed. Gross errors are often due to connection issues. In addition here is a link to FAQ regarding our temperature sensors, it may help answer some general questions

    e2e.ti.com/.../404572

    Please let me know if the problem is resolved.

     

    Guang

    Apps-Sensing Products

  • Hi Guang,

    Yes, I am able to read the local temperature, I am able to communicate with the device.

    When i check the BUSY flag, It is set(Logic 1). It is not going to to Logic 0.

    When my remote sensor is disconnected, I got temperature 0x00 and when it is connected i got temperature 0xC0..

    Do you think the diode configuration/connection was issue?

    -Thamizh
  • Hi Thamizh,

    When the config registers are left in POR state, the conversion is continuous at 8 samples/second. You may have caught BUSY bit when device is indeed in the middle of a conversion. A more meaningful test is to put the device in ShutDown (write 40H to config register 09H), after about 100mS, BUSY should be cleared and stay that way. You can always issue a one-shot command in ShutDown mode to have the device wake up, do one conversion and then go back to SD.

    I would check to make sure the remote diode connection is sound; there is no excessive resistance/capacitance. For the sake of debug, if you are not already using a discrete remote diode, maybe you can try the recommended 2N3906 (PNP) or 2N3904 (NPN).

    Guang

    Apps-Sensing Products