Description

The A1244 is a two-wire Hall-effect latch. The devices are

process, which implements a patented high frequency, 4-phase,

chopper-stabilization technique. This technique achieves

magnetic stability over the full operating temperature range,

and eliminates offsets inherent in devices with a single Hall

element that are exposed to harsh application environments.

Two-wirelatchesareparticularlyadvantageousincost-sensitive

applications because they require one less wire for operation

versus the more traditional open-collector output switches.

Additionally, the system designer inherently gains diagnostics

because there is always output current flowing, which should

be in either of two narrow ranges. Any current level not within

these ranges indicates a fault condition.

The Hall-effect latch will be in the high output current state

in the presence of a magnetic south polarity field of sufficient

magnitude and will remain in this state until a sufficient north

polarity field is present.

The device is offered in two package styles. The LH is a

SOT-23W style, miniature low profile package for surface-

mount applications. The UA is a 3-pin ultra-mini single inline

package (SIP) for through-hole mounting. Both packages are

lead (Pb) free, with 100% matte tin leadframe plating.

A1244-DS, Rev. 1

Features and Benefits

▪ High speed, 4-phase chopper stabilization

▫ Low switchpoint drift throughout temperature range

▫ Low sensitivity to thermal and mechanical stresses

▪ On-chip protection

▫ Supply transient protection

▫ Reverse battery protection

▪ On-board voltage regulator

▫ 3.0 to 24 V operation

▪ Solid-state reliability

▪ Robust EMC and ESD performance

▪ Industry leading ISO 7637-2 performance through use of

proprietary, 40-V clamping structures

Chopper-Stabilized, Two Wire Hall-Effect Latch

Functional Block Diagram

A1244

Amp

Regula

To all subcircuits

tor

Schmitt

Trigger

Polarity

Low-Pass

Filter

GND

VCC

GND

UA package only

0.01 μF

V+

Clock/Logic

Not to scale

Packages:

Approximate footprint

3-pin SOT23-W

2 mm × 3 mm × 1 mm

(suffix LH)

3-pin ultramini SIP

1.5 mm × 4 mm × 3 mm

(suffix UA)