Texas Instruments MSP430x4xx - Manual (Page 392)

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 20−10.
When using the temperature sensor, the sample period must be greater than
30
µ s. 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 V
REF+
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 20−10. Typical Temperature Sensor Transfer Function
Celsius
Volts
0 50 100
1.000
0.800
0.900
1.100
1.200
1.300
−50
0.700
V
TEMP
=0.00355(TEMP
C
)+0.986