TLE4998P3CE1200 Datasheet, PDF (25/32 Pages) Infineon Technologies AG – Programmable Linear Hall Sensor

TLE4998P3C E1200
Temperature Compensation
8
Temperature Compensation
The magnetic field strength of a magnet depends on the temperature. This material
constant is specific to different magnet types. Therefore, the TLE4998P3C E1200 offers
a second-order temperature compensation polynomial, by which the Hall signal output
is multiplied in the DSP.
There are three parameters for the compensation:
• Reference temperature T₀
• A linear part (1^st order) TC₁
• A quadratic part (2^nd order) TC₂
The following formula describes the sensitivity dependent on the temperature in relation
to the sensitivity at the reference temperature T₀:
S_TC(T) = 1 + TC₁ × (T – T₀) + TC₂ × (T – T₀)²
For more information, see also the signal-processing flow in Figure 6.
The full temperature compensation of the complete system is done in two steps:
1. Pre-calibration in the Infineon final test
The parameters TC1, TC2, T0 are set to maximally flat temperature characteristics
regarding the Hall probe and internal analog processing parts.
2. Overall system calibration
The typical coefficients TC1, TC2, T0 of the magnetic circuitry are programmed. This
can be done deterministically, as the algorithm of the DSP is fully reproducible. The
final setting of the TC1, TC2, T0 values depend on the pre-calibrated values.
Table 16 Temperature Compensation
Parameter
Symbol Limit Values Unit
Notes
min. max.
Register size TC₁
TL
1^st order coefficient TC₁ TC₁
-
9
bit
Unsigned integer values
-1000 2500 ppm/ °C ¹⁾
Quantization steps of TC₁ qTC₁
15.26 ppm/ °C
Register size TC₂
TQ
2^nd order coefficient TC₂ TC₂
-
8
-4 4
bit
Unsigned integer values
ppm/ °C² ²⁾
Quantization steps of TC₂ qTC₂
0.119 ppm/ °C²
Reference temp.
T₀
- 48 64 °C
Quantization steps of T₀ qT₀
1
°C
3)
1) _{Relative range to Infineon TC1 temperature pre-calibration, the maximum adjustable range is limited by the}
register-size and depends on specific pre-calibrated TL setting, full adjustable range: -2441 to +5355 ppm/°C
Data Sheet
25
Rev 1.1, 2009-09