Two-point Calibration

To make the temperature measurements as accurate as possible, two calibration points are needed. The first calibration point, ADC_T1, is the output from the ADC_T2 at the first calibration temperature, T1. This application note uses room temperature (25°C) as this first calibration temperature. The second calibration point, ADC_T2, is the output at the second calibration temperature, T2. The second temperature should be chosen a little higher than the temperature range of interest. The output from the ADC is given in LSBs or K, so the calibration values ADC_T1 and ADC_T2 have to be converted to °C. This is done by subtracting 273 from the values.