3161

HALL-EFFECT SWITCH

FOR 2-WIRE APPLICATIONS

115 Northeast Cutoff, Box 15036

Worcester, Massachusetts 01615-0036 (508) 853-5000

Suffix “LT”

SENSOR LOCATIONS

OPERATION

The output of these devices (pin 3) switches OFF when the magnetic

field at the Hall sensor exceeds the operate point threshold (B

magnetic field is reduced to below the release point threshold (B

device output switches ON. The difference in the magnetic operate and

release points is called the hysteresis (B

hysteresis allows clean switching of the output even in the presence of

external mechanical vibration and electrical noise.

Suffix “UA”

APPLICATIONS INFORMATION

These devices are normally operated in a 2-wire mode, where the supply

terminal and the output terminal are tied together. An external comparator

detects the change in total supply current by the addition (output off, B > B

or subtraction (output on, B < B

Hall effect applications information is available in the “Hall-Effect IC

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

MicroSystems Electronic Data Book, AMS-702 or Application Note 27701,

or at

TYPICAL 2-WIRE APPLICATION

0.045"

1.14 mm

1

3

2

Dwg. MH-008-7

0.030"

0.76 mm

NOM

ACTIVE AREA DEPTH

0.085"

2.16 mm

A

1

3

2

Dwg. MH-011-8

0.018"

0.46 mm

NOM

BRANDED

SURFACE

ACTIVE AREA DEPTH

0.078"

1.98 mm

0.054"

1.36 mm

A

0.85 V

V

CC

100

Ω

Dwg. EH-011A

0.1

µF

SUPPLY

–

+

100

125

150

175

200

3.0

0

MAGNETIC FLUX DENSITY in GAUSS

12

9.0

6.0

75

Dwg. GH-007-1

50

25

0

15

°C

Allegro