ADC12 Operation
20-16 ADC12
20.2.8 Using the Integrated Temperature Sensor
To use the on-chip temperature sensor, the user selects the analog input
channel INCHx = 1010. Any other configuration is done as if an external
channel was selected, including reference selection, conversion-memory
selection, etc.
The typical temperature sensor transfer function is shown in Figure 20โˆ’10.
When using the temperature sensor, the sample period must be greater than
30 ยตs. The temperature sensor offset error can be large, and may need to be
calibrated for most applications. See device-specific datasheet for
parameters.
Selecting the temperature sensor automatically turns on the on-chip reference
generator as a voltage source for the temperature sensor. However, it does not
enable the VREF+ output or affect the reference selections for the conversion.
The reference choices for converting the temperature sensor are the same as
with any other channel.
Figure 20โˆ’10. Typical Temperature Sensor Transfer Function
Celsius
Volts
0 50 100
1.000
0.800
0.900
1.100
1.200
1.300
โˆ’50
0.700
VTEMP=0.00355(TEMPC)+0.986