High-Accuracy, Pulse-Width or AK Protocol

Hall-Effect Wheel Speed and Direction Sensor IC

A19302

12

Allegro MicroSystems

955 Perimeter Road

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

www.allegromicro.com

Calibration and Direction Validation

When power is applied to the A19302, the built-in algorithm per-

forms an initialization routine. For a short period after power-on,

the device calibrates itself and determines the direction of target

rotation. Once the calibration routine is complete, the A19302

will transmit accurate speed and direction information.

Target Rotation

N

Target Magnetic

Differential Profile

t

Opposite

North Pole

Opposite

South Pole

Opposite

N→S Boundary

Opposite

S→N Boundary

Device Location at Power-On

NN

SS

S

Figure 11: Calibration Behavior (-xBx Variant)