TLE4925 Datasheet, PDF (24/25 Pages) Infineon Technologies AG – Differential Hall Sensor

PRELIMINARY
Stochastic Phase Error ∆ϕ
The stochastic phase error includes the error due to the variation of the delay time with
temperature and the error caused by the resolution of the threshold. It can be calculated
in the following way:
∆ϕ _d
=
360° •
60
n
•
∆t_d
∆ϕ_d ... stochastic phase error due to the variation of the delay time over temperature in °
n
… speed of the camshaft wheel in min^-1
∆t_d … variation of delay time over temperature in sec
Jitter (Repeatability)
B
∂B
∂ϕ
Bdiff_max
Bdiff_typ
1σ
3σ
Noise
The phase jitter is normally caused by the
analogue system noise. If there is an update of the
offset-DAC due to the algorithm, what could happen
after each tooth, then an additional step in the
phase occurs (see description of the algorithm).
This is not included in the following calculations.
The noise is transformed through the slope of the
magnetic edge into a phase error. The phase jitter
is determined by the two formulas:
Figure17: Phase-Jitter
ϕ
Phase-Jitter
( ) ϕ _{Jitter _typ}
=
∂ϕ
∂B
•
B_{neff _typ}
( ) ϕ _{Jitter _max}
=
∂ϕ _•
∂B
B_{neff _max}
Page 24 of 25