16.6.9 Voltage Reference System Operation

The Voltage Reference System (VREF) consists of a Bandgap Reference Voltage Generator and a temperature sensor.

The Bandgap Reference Voltage Generator is factory-calibrated under typical voltage and temperature conditions.

At reset, the VREF.CAL register value is loaded from Flash Factory Calibration.

The temperature sensor can be used to get an absolute temperature in the temperature range of CMIN to CMAX degrees Celsius. The sensor will output a linear voltage proportional to the temperature. The output voltage and temperature range are located in the Electrical Characteristics. To calculate the temperature from a measured voltage, the following formula can be used:

C_{MIN} + (Vmes + - Vou t_{MAX}) \frac{∆temperature}{∆voltage}