AN4159
Software
Doc ID 023639 Rev 3
17/27
General presentation of the concept
A linear pressure temperature compensation is implemented in the ASIC, using 3
embedded sensor calibration point information.
A second order of accuracy can be achieved (less pressure variation when temperature
changes) by implementing a quadratic compensation (second order polynomial
approximation) on top of the piecewise linear (PWL) one, by S/W, using the same calibration
data built-in the sensor registers.
Here we describe the basic quadratic concept, assuming the T0 = 10 °C:
Figure 7.
Overview first to second order compensation
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Input parameters: TCV1, TCV2, TCS1, TCS2, Dgain
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Constants parameter: T1=480*(10-42.5)LSB; T2=0 LSB, T3=480*(70-42.5) LSB;
P0=1000mbar.
Step 1: pressure calibration points calculation
Equation 1
