Large Air Gap, GMR Transmission

Speed Sensor IC for Gear Tooth Sensing

ATS19480

10

Allegro MicroSystems

955 Perimeter Road

Manchester, NH 03103-3353 U.S.A.

www.allegromicro.com

Tooth

Valley

Target

Power-On Angle

Figure 4: Output after power-on

Power-On (Calibration)

After power is applied to the sensor IC, the IC internally detects

the magnetic profile of the target. Operation begins with a cali-

bration period, during which the sensor IC provides output edges,

but full edge accuracy may not be achieved until Calibration is

complete.