MSPM0G3505: MCU's ADC module can not run normally after boot when MCU works in room temperature (27 deg)

Hai Phan

Part Number: MSPM0G3505
Other Parts Discussed in Thread: SYSCONFIG

Tool/software:

Recently, I encountered an issue while testing approximately 100 of our products that use the MSPM0G3505 MCU. Five of them failed to operate as expected. Specifically, when powered, the devices are supposed to send ADC values via UART. However, during testing, all the ADC values were consistently 0, even though I confirmed that the voltage at the ADC pins was not zero.

To troubleshoot, I applied heat to the MCU using a heat gun, raising its temperature to about 100°C. Afterward, I repeated the test, and the devices functioned as expected. However, once the MCU's temperature returned to room temperature, the ADC values stopped working again.

Has anyone encountered a similar issue? Could this be related to the temperature sensor module or some configuration in SysConfig, even though I haven’t made any changes to it?

I’d greatly appreciate any insights or suggestions.

Thank you for taking the time to read this.

10 months ago

0 Brian Dempsey 10 months ago

TI__Expert 5225 points

Hi Hai, can you provide a few more details on what the ADC input is here? Are you reading from the internal temp sensor, or from an external source?

-Brian

0 Hai Phan 10 months ago in reply to Brian Dempsey

Prodigy 120 points

I use ADC module only for reading voltage on resistor divider and Op-amp output, I do not use any function that relates to internal temperature sensor

0 Brian Dempsey 9 months ago in reply to Hai Phan

TI__Expert 5225 points

Hi Hai, thanks for the additional information. If you set a breakpoint in the code just after the ADC reading, do you get '0' there as well? Just trying to rule out any issues storing the ADC value and transmitting via UART.

0 Hai Phan 9 months ago in reply to Brian Dempsey

Prodigy 120 points

Thank you for your suggestion, but in my program, I set condition if ADC's value equal to zero, system's state will not change. About the problem we are talking about, system's state did not change so I guess the ADC's value that MCU read was actually zero, not due to UART transmission error

0 Brian Dempsey 9 months ago in reply to Hai Phan

TI__Expert 5225 points

Hi Hai, ok, if possible can you set the breakpoint to verify the ADC value is 0? We ruled out the UART, I want to rule out any issue in the firmware logic so we can narrow down the source of the issue. Can you also go into sysconfig and verify the ADC channel assignments match with the hardware?

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MSPM0G3505: MCU's ADC module can not run normally after boot when MCU works in room temperature (27 deg)