TLE4997 Datasheet, PDF (28/36 Pages) Infineon Technologies AG – Programmable Linear Hall Sensor for Industrial Use

TLE4997I
Temperature Compensation
8.1
Parameter Calculation
The parameters TC₁, TC₂ and T₀ may be calculated by:
TC₁
=
-^T----^L-----–----1---6---0-- × 1000000
65536
TC₂
=
T_-----Q_{------–----1---2---8-- × 1000000}
8388608
T₀ = 16TR – 48
Now the output V_OUT for a given field B_IN at a specific temperature can be roughly
calculated by:
V_OUT
=



--^B-----^I--^N---
B_FSR
×
S_TC
×
S_TCHall
×
So
×

V_{DD}
+ V_OS
B_FSR is the full range magnetic field. It is dependent on the range setting (e.g 100 mT).
S_o is the nominal sensitivity of the Hall probe times the Gain factor set in the EEPROM.
S_TC is the temperature-dependent sensitivity factor calculated by the DSP.
S_TCHall is the temperature behavior of the Hall probe.
The pre-calibration at Infineon is performed such that the following condition is met:
S_TC(T_J – T₀) × S_TCHall(T_J) ≈ 1
Within the application, an additional factor B_IN(T) / B_IN(T0) will be given due to the
magnetic system. S_TC needs now to be modified to S_TCnew so that the following condition
is satisfied:
--^B----^I--^N----⁽--T----⁾--
B_IN(T₀)
×
S_TCnew(T)
×
S_TCHall(T)
≈
S_TC(T)
×
S_TCHall(T)
≈
1
Therefore, the new sensitivity parameters S_TCnew can be calculated from the
pre-calibrated setup S_TC using the relation:
--^B----^I--^N----⁽--T----⁾--
B_IN(T₀)
×
S_TCnew(T)
≈
S_TC(T)
Data Sheet
28
V 1.0, 2007-06