C8051F310/1/2/3/4/5/6/7
The uncalibrated temperature sensor output is extremely linear and suitable for relative temperature mea-
surements (see Table 5.1 for linearity specifications). For absolute temperature measurements, gain and/
or offset calibration is recommended. Typically a 1-point calibration includes the following steps:
Step 1. Control/measure the ambient temperature (this temperature must be known).
Step 2. Power the device, and delay for a few seconds to allow for self-heating.
Step 3. Perform an ADC conversion with the temperature sensor selected as the positive input
and GND selected as the negative input.
Step 4. Calculate the offset and/or gain characteristics, and store these values in non-volatile
memory for use with subsequent temperature sensor measurements.
Note that
parameters which affect ADC measurement, in particular the voltage reference value, will also
affect temperature measurement.
5.00
5.00
4.00
4.00
3.00
3.00
2.00
2.00
Error (degrees C)
1.00
1.00
0.00
-40.00
-1.00
-20.00
0.00
20.00
40.00
60.00
0.00
80.00
-1.00
-2.00
-2.00
-3.00
-3.00
-4.00
-4.00
-5.00
-5.00
Temperature (degrees C)
Figure 5.3. Temperature Sensor Error with 1-Point Calibration
Rev. 1.7
53
SILABS [ SILICON LABORATORIES ]
