Besides the current sensing and protection, the modules also have a built-in thermistor for temperature sensing and protection. Because this NTC is located on the same substrate as the IGBT and diodes and its location is quite close to the junction of IGBT, there is a good correlation between the NTC temperature and junction temperature. This correlation is usually recorded and is shown in the datasheet, so in an application, the user can sense the NTC voltage and calculate the NTC resistor. This is a function of temperature so the user will know the NTC temperature based on this correlation curve and can estimate the IGBT temperature. This is valuable information which is needed for device protection.