• State Resolved
  • Locked Locked
  • Replies 7 replies
  • Subscribers 32 subscribers
  • Views 1047 views
  • Users 0 members are here
Support feedback
Options
Options
Similar topics

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

LM73 - Software reset for abnormal temperature readings

Kawai
Guru 19775 points
Other Parts Discussed in Thread: LM73

Hi Team,

Please allow me to ask you about the software reset which is shown in the LM73 datasheet page.22 "9. Power Supply Recommendations".

[Question]
Does the LM73 re-load the data from EEPROM to the registers by implementing the software reset shown in the datasheet page.22 ?

Our customer is facing the abnormal temperature readings by having slower ramp up time than 0.7V/ms. Abnormal temperature reading is occurring less frequently. I have read the existing LM73 abnormal data problem posts and understanding that software reset is the measures for this problem if user could not change the power supply ramp rate. Is my recognition correct ?

Thanks in advance.

Best Regards,
Kawai

  • 0
    TI__Genius 15760 points
    Hi Takushi-san,

    SVA team will get back to you shortly on this question.

    Regards.
  • 0
    TI__Expert 7220 points
    Hi Takushi-san,

    The LM73 does reload the data from the EEPROM to the registers after the software reset. This means the registers do not return to their POR values after executing the software reset.

    -Michael Wong
  • 0 in reply to Michael Wong
    Guru 19775 points
    Hello Michael-san,

    Thank you very much for your support and I apologize for my delay.

    I am still not clear about the difference between the POR and software reset in the point of the register settings.

    Q1) Could you please explain in detail the difference between POR and software reset ?

    Q2) Which registers would have differences ?

    Q3) What is the information loaded from the EEPROM ? I believe we do not have access to EEPROM.

    Thanks in advance.

    Best Regards,
    Kawai
  • 0 in reply to Kawai
    TI__Expert 7220 points
    Hi Takushi-san,

    A1) POR register values are the default register values when the LM73 has been turned off and on, it is a hardware reset of the part. Software reset is a reset by setting the register value stated on page 22 "Power Supply Recommendations". Writing this sequence will restart the part but will not actually turn off the part (remove VDD). When the software reset is executed the register values before the reset will be rewritten to the appropriate registers.

    A2) None of the registers will have differences as the register values before the reset will be rewritten to the appropriate registers.

    A3) The information on the EEPROM are the register values before the software restart execution.

    -Michael Wong
  • 0 in reply to Michael Wong
    Guru 19775 points
    Hi Michael-san,

    I apologize for my delay, thank you very much for the answers. Please allow me to ask you one more question.

    If the user could not meet the recommended power supply ramp up time, would soft reset of the device be the assured permanent measures to the problem reading an abnormal temperature ?

    Best Regards,
    Kawai
  • 0 in reply to Kawai
    TI__Expert 7220 points
    Hi Takushi-san,

    Yes, if the customer cannot meet the power supply ramp time then they will have to do a soft reset on the part. The LM73 should read a normal temperature after the soft restart sequence has been executed.

    -Michael Wong
  • 0 in reply to Michael Wong
    Guru 19775 points
    Hello Michael-san,

    We greatly appreciate for your help. Thank you very much.

    Best Regards,
    Kawai