Question
How do I use the on-chip temperature sensor feature of the ADuC834?
Answer
The temperature sensor on the ADuC834 is converted by the auxiliary ADC to
output a digital
code to represent the chip temperature. The auxiliary ADC must be configured in
bipolar mode
using the internal voltage reference in order for the temperature sensor to
produce sensible results.
The temperature sensor is calibrated in the factory at 25°C so that the ADC
conversion result is
8000h at 0°C with 256 counts per °C.
e.g. An ADC conversion result of 9680h represents a temperature of 22.5°C.
An ADC conversion result of 6756h represents a temperature of –24.66°C.
And remember, the on-chip temperature sensor is measuring chip temperature, not
ambient
temperature, so don’t forget to factor self-heating into the equation if you
wish to determine the
temperature of the ambient air.