JAJSIU8B June 2015 – April 2020 ADS131E08S
Setting CHnSET[2:0] = 100 sets the channel input to the temperature sensor. This sensor uses two internal diodes with one diode having a current density 16 times that of the other, as shown in Figure 18. The difference in diode current densities yields a difference in voltage that is proportional to absolute temperature.
The internal device temperature tracks the PCB temperature closely because of the low thermal resistance of the package to the PCB. Self-heating of the ADS131E08S causes a higher reading than the temperature of the surrounding PCB. Setting the channel gain to 1 is recommended when the temperature measurement is taken.
The scale factor of Equation 3 converts the temperature reading to °C. Before using this equation, the temperature reading code must first be scaled to μV.