TheA1150,A1152,A1153,A1155,A1156,A1157, andA1158

comprise a family of two-wire, unipolar, Hall-effect switches,

which are factory-trimmed to optimize magnetic switchpoint

accuracy.ThesedevicesareproducedontheAllegro™advanced

BiCMOS wafer fabrication 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.

The A115x family has a number of automotive applications.

These include sensing seat track position, seat belt buckle

presence, hood/trunk latching, and shift selector position.

Two-wire unipolar switches are particularly advantageous in

cost-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.

All family members are offered in three package styles. The

LH is a SOT-23W style, miniature, low profile package for

surface-mountapplications.TheUAisa3-pin,ultra-mini,single

inline package (SIP) for through-hole mounting. The UB is a

2-pin, ultra-mini, single inline package (SIP) for through-hole

mounting. All three packages are lead (Pb) free, with 100%

matte-tin leadframe plating.

A1152-DS, Rev. 10

• AEC-Q100 automotive qualified

• 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 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 Switches

Functional Block Diagram

A1150, A1152, A1153, A1155, A1156, A1157, and A1158

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)

Amp

Regula

To all subcircuits

tor

Schmitt

Trigger

Polarity

Low-Pass

Filter

GND

VCC

GND

UA package only

UB package only

LH & UA

package

only

0

0

.

.

01

1

µF

µF

V+

Clock/Logic

2-pin ultramini SIP

1.5 mm × 4 mm × 4

mm (suffix UB)

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FEATURES AND BENEFITS

DESCRIPTION