Chopper-Stabilized Omnipolar Hall-Effect Switch

A1126

9

Allegro MicroSystems, LLC

115 Northeast Cutoff

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

1.508.853.5000; www.allegromicro.com

Functional Description

The output of these devices switches low (turns on) when a

magnetic field perpendicular to the Hall sensor chip exceeds the

of 30 mA. When the magnetic field is reduced below the release

ence in the magnetic operate and release points is the hysteresis,

ing of the output even in the presence of external mechanical

vibration and electrical noise.

In the case of omnipolar switch devices, removal of the magnetic

field results in the device output high (off).

Figure 1. Switching behavior of omnipolar switches. On the horizontal axis, the

B+ direction indicates increasing south polarity magnetic field strength, and the

B– direction indicates increasing north polarity. This behavior can be exhibited

when using a circuit such as that shown in figure 2.

B+

B–

V+

0

0