MSPM0G1518: internal temperature is not correct

Frank(EP) Liu

Expert 4920 points

Part Number: MSPM0G1518
Other Parts Discussed in Thread: MSPM0G3519

Tool/software:

hi Expert,

My customer uses MSPM0G1518.

they gets below from IC.

adcResult is 784 with VDDA 3.3V as vref

TEMP_SENSE0 is 1878

based on datasheet.

the temperature is 35C. the environment temperature is ~27C.

it's much higher.

Can I know why?

if I set the trim temperature to 22C, the result is 27.5C which is much close to real condition.

BR,

frank

3 months ago

0 Kier 3 months ago

Mastermind 9470 points

Frank(EP) Liu said:
Can I know why?

The purpose of temperature sensor is to measure the temperature of the device not the environment temperature. This is so you can ensure that the device does not exceed its rated temperature. e.g. The die junction temperature must not exceed 125 degrees.

The device will always be hotter than the environment because it is converting electrical energy to thermal energy due switching losses of the millions of transistors in the device.

You can only infer the environment temperature by calculation, you cannot measure it with this method.

0 Frank(EP) Liu 3 months ago in reply to Kier

TI__Expert 4920 points

Kier,

In previous build, they use MSPM0G3519(also engineer sample).

it works normally at the same test.

Just want to confirm that the engineer sample is trimmed with 30C, right?

BR,

frank

0 Kier 3 months ago in reply to Frank(EP) Liu

Mastermind 9470 points

Frank(EP) Liu said:
it works normally at the same test.

What do you mean by normal? That the device temperature = ambient air temperature?

0 Frank(EP) Liu 3 months ago in reply to Kier

TI__Expert 4920 points

Kier,

yes, it's close.

BR,

frank

0 Kier 3 months ago in reply to Frank(EP) Liu

Mastermind 9470 points

The device must always be warmer than the environment and the degree depends on the work done by the device. In low power mode, I think a few degrees warmer might be possible but I'm just guessing. In a non-low power mode, 5 to 10 degrees warmer sounds plausible to me.

0 Helic Chi 3 months ago in reply to Kier

TI__Mastermind 20187 points

For the x mark sample chips, please compare the temp calibration value and ADC convert result.

To help you identify whether the chips has valid calibration temp value.

Arm-based microcontrollers

Arm-based microcontrollers forum

MSPM0G1518: internal temperature is not correct