TLE 4941, TLE 4941 C
TLE 4941 - TLE 4941C Data Sheet April 2001
1
Appendix B release 1.0
1. Occurrence of initial calibration delay time td,input
If there is no input signal (standstill), a new initial calibration is triggered each 0.7s. This
calibration has a duration td,input of max. 300µs. No input signal change is detected during that
initial calibration time.
In normal operation (signal startup) the probability of td,input to come into effect is:
td,input / time frame for new calibration 300µs/700ms = 0,05%.
After IC resets (e.g. after a significant undervoltage) td,input will always come into effect.
2. Magnetic input signal extremely close to a switching threshold of PGA at signal
startup:
After signal startup generally all PGA switching into the appropriate gain state happens within
less than one signal period. This is included in the calculation for nDZ-Start. For the very rare
case that the signal amplitude is extremely close to a PGA switching threshold and the full
range of following speed ADC respectively, a slight change of the signal amplitude can cause
one further PGA switching. It can be caused by non-perfect magnetic signal (e.g. amplitude
modulation due to tolerances of pole-wheel, tooth wheel or air gap variation). This additional
PGA switching can result in a further delay of the output signal (nDZ-Start) up to three magnetic
edges leading to a worst case of nDZ-Start=9. Due to the low probability of this case it is not
defined as max. value in the data sheet.
(For a more detailed explanation please refer to the document "TLE 4941/42 - Frequently
Asked Questions").
