45.6.3.1 Device Temperature Measurement

The device provides two temperature sensors (TSENSP and TSENSC, respectively) at different locations in the die, controlled by the SUPC - Supply Controller. The output voltages from the sensors, VTP and VTC, can be sampled by the ADC.

The respective temperature sensor selection is dependent on the configuration of SUPC:

  • If the SUPC is not in on-demand mode (SUPC.VREF.ONDEMAND=0), and if SUPC.VREF.TSEN=1 and SUPC.VREF.VREFOE=0, the temperature sensor is selected by writing to the Temperature Sensor Channel Selection bit in the Voltage Reference System Control register (SUPC.VREF.TSSEL).

    The state of the MUX input selection bit fields in the ADC Input Control register (ADC.INPUTCTRL.MUXPOS and MUXNEG) does not affect the sensor selection.

  • If the SUPC is in on-demand mode in (SUPC.VREF.ONDEMAND=1) and SUPC.VREF.TSEN=1, the output will be automatically set to the sensor requested by the ADC, independent of SUPC.VREF.TSSEL. SUPC.VREF.VREFOE can also be set to '1'.

    Which temperature sensor is requested by the ADC is selected by writing to the Positive MUX Input Selection bits in the Input Control register (ADC.INPUTCTRL.MUXPOS).

Using the two conversion results, TP and TC, and the temperature calibration parameters found in the NVM Software Calibration Area, the die temperature T can be calculated:

T = TL ⋅ VPH ⋅ TC − VPL ⋅ TH ⋅ TC − TL ⋅ VCH ⋅ TP + TH ⋅ VCL ⋅ TP VCL ⋅ TP − VCH ⋅ TP − VPL ⋅ TC + VPH ⋅ TC

Here, TL and TH are decimal numbers composed of their respective integer part (TLI, THI) and decimal parts (TLD and THD) from the NVM Software Calibration Area.

Note: The accuracy is dependent on the current temperature, and degrades towards extreme conditions.