3503

RATIOMETRIC,

LINEAR

HALL-EFFECT SENSORS

115 Northeast Cutoff, Box 15036

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

GEAR TOOTH SENSOR

CURRENT MONITOR

OPERATION

The output null voltage (B = 0 G) is nominally one-half the supply

voltage. A south magnetic pole, presented to the branded face of the Hall-

effect sensor will drive the output higher than the null voltage level. A north

magnetic pole will drive the output below the null level.

In operation, instantaneous and proportional output-voltage levels are

dependent on magnetic flux density at the most sensitive area of the device.

Greatest sensitivity is obtained with a supply voltage of 6 V, but at the cost of

increased supply current and a slight loss of output symmetry. The sensor's

output is usually capacitively coupled to an amplifier that boosts the output

above the millivolt level.

In two applications shown, a permanent bias magnet is attached with

epoxy glue to the back of the epoxy package. The presence of ferrous material

at the face of the package acts as a flux concentrator.

The south pole of a magnet is attached to the back of the package if the

Hall-effect IC is to sense the presence of ferrous material. The north pole of a

magnet is attached to the back surface if the integrated circuit is to sense the

absence of ferrous matrial.

Calibrated linear Hall devices, which can be used to determine the actual

flux density presented to the sensor in a particular application, are available.

SUFFIX “LT”

SUFFIX “UA”

Dwg. A-12,513

Dwg. A-12,512

N

3

1

2

NOTCH SENSOR

Dwg. A-12,574

SENSOR LOCATIONS

SUFFIX “U”

A

1

3

Dwg. MH-002-5C

0.015"

0.38 mm

NOM

0.072"

1.83 mm

BRANDED

SURFACE

ACTIVE AREA DEPTH

2

0.093"

2.37 mm

0.042"

1.08 mm

1

3

2

Dwg. MH-008-9

0.030"

0.76 mm

NOM

ACTIVE AREA DEPTH

0.091"

2.32 mm

A

1

3

Dwg. MH-011-3C

0.018"

0.46 mm

NOM

BRANDED

SURFACE

ACTIVE AREA DEPTH

2

0.056"

1.43 mm

A

0.084"

2.13 mm