The Charge Time Measurement Unit (CTMU), introduced on the latest generation of PIC24F and PIC18F devices, uses a constant current source to calculate both capacitance changes and the time difference between events. The same current source can also be used to measure temperature by exploiting a basic principle of semiconductor physics. This allows the use of a common and inexpensive diode, in the place of a relatively more expensive thermistor or other temperature sensor. This brief describes the basic concepts of temperature measurement using the CTMU.
Temperature Measurement, CTMU, PIC24F, PIC18F