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TMP102-Q1: Delay register setting

Part Number: TMP102-Q1
Other Parts Discussed in Thread: TMP102

Hello,

Is there specific time from register setting to effective the setting value?

My customer measured it that 1~3 sec from writing the register of ALERT threshold to applying the setting.

Is this expected operation?

Best regards,

Katsu 

  • Dear Katsu - 

    I would not expect seconds here. Is it possible that the customer set the ALERT, then the time they observe for it to activate is temperature rise time related? what is the exact flow/order of operations and timing with which they are testing this out? 

  • Hi Josh-san,

    Thank you for your response.

    Regarding test procedure, at first, system was into 85degC, then it turned on power. TMP102 shows TEMP_ALERT=LOW due to default temperature of Thigh is 80degC. After that, Thigh changed  to 100degC. Customer measured from register write to TEMP_ALERT got LOW.

    Do you have any advice us?

    Best regards,

    Katsu

  • Katsu - 

    are you saying that it takes seconds to go from 85C to 100C in a chamber? seems reasonable or even too short, as a 15C rise in temperature, i would expect that to take several minutes to attain and then stabilize.

    Here, you also have the option of following what is described on page 11 of the datasheet (section 7.3.7) to see if the messaging is correct from the device after the ALERT pin fires and is recognized by the MCU. 

    Also, you do have I2C pullups for SDA and SCL in your design, correct?  

  • Josh-san,

    No, temperature didn't change.

    Register value of Thigh was changed from 80degC(default) to 100degC. When Thigh=100degC effectives device's temperature(85degC) is under alert temperature. TEMP_ALERT should be LOW. It takes 1~3 sec from register write to TEMP_ALERT goes HIGH.

    Best regards,

    Katsu

  • Dear Katsu - 

    That is clearer, I think I understand your meaning. The part does come up in comparator mode on power up and will be measuring - it may take a few seconds that first time. Have you analyzed the I2C traffic here with regards to what/when the settings are being changed and what the device is doing before and after that? if not, could that be done and shared here?