• State TI Thinks Resolved
  • Locked Locked
  • Replies 1 reply
  • Answers 1 answer
  • Subscribers 30 subscribers
  • Views 345 views
  • Users 0 members are here
Support feedback
Options
Options
Related

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.

CCS/LAUNCHXL2-570LC43: On-die temperature measurement

Sindhu Krishna
Expert 1350 points
Part Number: LAUNCHXL2-570LC43
Other Parts Discussed in Thread: TMS570LC4357

Tool/software: Code Composer Studio

Hello Team TI,

I use the code for On-Die Temperature Measurement provided in the link

Also I pasted a Thermocouple on the TMS570LC4357 IC. The temperature measured by Thermocouple is 55.4 deg Cel and the debugger breakpoint at JunctionTemperature Variable displays 41.9 deg Celcius.

As this is a large variation, I would like to understand if there is calibration required for the code in this zip file.

Also does the USB centralized Power-up to all the components of the Launchpad create such a temperature increase to 55.4 deg Cel on uC?

Kindly support.

  • 0
    TI__Mastermind 21425 points
    Hello,
    The on-die temperature sensors are designed to be used with software calibration. To support software calibration of the temperature sensors, TI has recorded the value returned by recording the reading of each sensor at different junction temperatures. The measurements were done while the device is still in wafer form and the junction temperature can be well controlled by the wafer prober.. Calibration information is stored in TI OTP.
    In example code you are mentioning, calibration procedure in performed in thermistor_calibration() function. ADC module has calibration procedure as well. In demo code Mid point calibration is performed using adcMidPointCalibration(adcREG2) function call. More on ADC calibration can be found in Section 22.2.6.1 ADC Error Calibration Mode of device TRM ( www.ti.com/.../spnu563a.pdf ).
    There will be a difference between on-die sensor readings and any other sensor positioned outside. I don't know whether 6.3 deg C is big difference or not.
    The temperature of MCU depends on many things. It depends on MCU load. It depends on Ambient temperature. It depends on PCB layou... and so on.

    Best regards,
    Miro