HALL-EFFECT LATCHES

FOR HIGH-TEMPERATURE

OPERATION

115 Northeast Cutoff, Box 15036

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

ELEMENT LOCATIONS

(±0.005” [0.13 mm] die placement)

Allegro

Package Designators “LT”

1

3

2

Dwg. MH-008-4C

0.0305"

0.775 mm

NOM

ACTIVE AREA DEPTH

0.050"

1.27 mm

0.090"

2.27 mm

A

Package Designators “UA”

1

3

2

Dwg. MH-011-4C

0.0195"

0.50 mm

NOM

BRANDED

SURFACE

ACTIVE AREA DEPTH

0.083"

2.10 mm

0.060"

1.51 mm

A

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

magnet, as shown below. Other methods of operation are possible.

Dwg. A-11,899

OPERATION

In operation, the output transistor is OFF until the strength of the mag-

netic field perpendicular to the surface of the chip exceeds the threshold or

tor switches ON and is capable of sinking 25 mA of current.

The output transistor switches OFF when magnetic field reversal results

in the transfer characteristics graph (A3187* shown).

Note that the device latches; that is, a south pole of sufficient strength

will turn the device ON. Removal of the south pole will leave the device ON.

The presence of a north pole of sufficient strength is required to turn the

APPLICATIONS INFORMATION

Extensive applications information on magnets and Hall-effect devices is

also available in the Allegro Integrated and Discrete Semiconductors Data

Book or Application Note 27701.

30 V

MAX

B

+

0

0

FLUX DENSITY

Dwg. GH-034-4

-B

RP

B

BB

V

OP

B

Although element location is accurate to three

sigma for a particular design, product improve-

ments may result in small changes to element

location.