TSENS0 and TSENS1 comparison

[apu_apustaja]

Hello, we're defining and implementing safety requirements in our system based on MPC5744P, while referring to the MPC5744P Safety Manual.

In it, the SM_066 quotes:

During power up, the two temperature sensors are to be read by
software (TSENS0 from ADC0 channel 15, TSENS1 from ADC1 channel 15). The
software must verify that the conversion values are similar, as this is a means of assessing
that the sensors are working properly. [end]

Is there a recommendation as for what does "similar" mean? Is there any information for what would be the theoretical maximum allowed difference between the two?

Thanks, and best regards

[davidtosenovjan]

Hi,

as accuracy of temperature sensor is defined as +/- 3%, 'similar' could be defined as difference up to 6%

[apu_apustaja]

Thanks for the response, could you please just clarify if these sensors are on the exact same physical location on the chip, where actual temperature differences would therefore be not very likely?

Or are they on separate locations, and actual temperature difference should be taken into consideration, and then the tolerable difference would be above 6%?

Because in our testing, the difference often shows >6%.