The  YH4913    omnipolar Hall effect sensor  IC is fabricated from mixed signal
CMOS technology. It incorporates advanced chopper-stabilization techniques to
provide accurate and stable magnetic switch points.
     The circuit design provides an internally controlled clocking mechanism to
cycle power to the Hall element and analog signal processing circuits. This serves
to place the high current-consuming portions of the circuit into a    Sleep” mode.
Periodically the device is  Awakened” by this internal logic and the     magnetic   flux
from   the  Hall  element    is evaluated  against   the   predefined  thresholds. If the
flux density is above or below the Bop/Brp thresholds then the output transistor is
driven to change states accordingly. While in the  Sleep” cycle the output transistor
is latched in its previous state. The design has been optimized for service in
applications requiring extended operating lifetime in battery powered systems.
The output transistor of the YH4913    will be latched on in the presence of a
sufficiently strong South or North magnetic field facing the marked side of the
package. The output will be latched off in the absence of a magnetic field.

Features
    2.2 V to 6.0 V battery operation
     High sensitivity and high stability of the magnetic switching points
     High resistance to mechanical stress
     Digital output signal
    Switching for both poles of a magnet (omnipolar)