Dual Channel Hall Effect Direction Detection Sensor IC

A3423

7

Allegro MicroSystems, LLC

115 Northeast Cutoff

Worcester, Massachusetts 01615-0036 U.S.A.

1.508.853.5000; www.allegromicro.com

Application Information

Operation with Fine-Pitch Ring Magnets

. For targets with a cir-

cular pitch of less than 4 mm, a performance improvement can be

observed by rotating the front face of the device (see below). This

rotation decreases the effective Hall element-to-element spacing,

provided that the Hall elements are not rotated beyond the width

of the target.

Applications

. It is strongly recommended that an external

0.01 μF bypass capacitor be connected (in close proximity to the

device) between the supply and ground of the device to

reduce both external noise and noise generated by the internal

logic.

The simplest form of magnet that will operate these devices is a

ring magnet. Other methods of operation, such as linear magnets,

are possible. Extensive applications information on magnets and

Hall-effect sensor ICs is also available in the “Hall-Effect IC

Applications Guide” which can be found in the latest issue of

Application Note 27701, at www.allegromicro.com/techpub2/an/

an27701.pdf.

E1

E2

E1

D

E2

D cos

Target Face Width, F

F < D sin

Target Circular Pitch, P

Normal Coplanar Alignment

Rotated Alignment

Target Profile of Rotation

NS

S