TLE4986C-XTS-M47

Programmable True Power On Sensor

General

Data Sheet

15

Revision 1.1, 2014-11-07

Figure 5

Hidden Hysteresis

The second form of hysteresis is called hidden hysteresis. This means, that the hysteresis cannot be observed

from outside. If the value of the switching level does not change, the output always switches at the same level.

However, inside the IC there are two distinct levels close above and below the switching level, which are used to

arm the output. This level can be programmed by having 2 options (for details see magnetic parameters). Hence,

if the value of the magnetic field crosses the lower of these hysteresis levels, then the output will be able to switch

if the field crosses the switching level. After this switching event the output is disabled until the value of the

magnetic field crosses one of the two hysteresis levels. If it crosses the upper hysteresis level, then the output is

armed again and can switch if the magnetic field crosses the switching level. On the other hand, if the magnetic

field does not reach the upper hysteresis level, but the lower hysteresis level is crossed again after a switching

event, then the output is allowed to switch, so that no tooth is lost. However, this causes an additional phase error.

Hidden_Hysteresis.vsd

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