SBOS685C – APRIL 2014 – REVISED JULY 2015
8.2.2 Narrow-Range Calibration Example: TOBJ = 33°C to 41°C, Unit vs Common Calibration
2.5 V to 5.5 V
Figure 56. Typical Application Circuit
220.127.116.11 Design Requirements
For this application, the system must operate over the environment described in Table 13.
Field of view
Table 13. Narrow-Range Requirements
Number of devices in calibration set
Minimum expected die temperature
Maximum expected die temperature
Minimum expected objected temperature
Maximum expected object temperature
Field of view subtended by object
Select a set of values for TDIE and TOBJ to generate the calibration set. At a minimum, include the four extreme
points of the temperature ranges desired. In practice, it is best to include a number of intermediate points as well.
This example uses the values shown in Table 14, with an X marking the values chosen for measurement. In this
application, the calibration set is weighted more densely around the region of interest.
Table 14. Narrow-Range Measurement Values
18.104.22.168 Detailed Design Procedure
Before attempting to calibrate the system, it is necessary to establish the stability of the system. Noise is a
measure of precision, which is the random deviation from the mean of the distribution. For a Gaussian (or
normal) distribution, the precision is typically characterized by the standard deviation (sensor noise), σ.
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