High Precision Hall Effect AC-Coupled Differential

Sensor IC with Integrated Filter Capacitor

A1421, A1422,

and

A1423

2

Allegro MicroSystems, Inc.

115 Northeast Cutoff

Worcester, Massachusetts 01615-0036 U.S.A.

1.508.853.5000; www.allegromicro.com

Each device includes: a voltage regulator, two Hall transduc-

ers, temperature compensating circuitry, a low-level ampli-

fier, bandpass filter, Schmitt trigger, and an output driver. The

on-board regulator permits operation with supply voltages from

4.0 to 26.5 V. The output stage can switch 20 mA over the full

frequency response range of the device, and is compatible with

CMOS logic circuits.

The devices in this family differ from each other in their

switchpoint specifications and their switching polarity. The

A1421 has a small hysteresis and asymmetrical switchpoints,

with one switchpoint at the zero-crossing. The A1422 has a small

hysteresis and symmetrical switchpoints, both near the zero-

crossing. The A1423 offers high vibration immunity, by means

of its larger hysteresis that establishes symmetrical switchpoints

Pin-out Diagram

Absolute Maximum Ratings

Characteristic

Symbol

Notes

Rating

Units

Supply Voltage

Refer to Power Derating section

28

V

Reverse Supply Voltage

–18

V

Output Current

25

mA

Reverse-Output Current

–50

mA

Operating Ambient Temperature

Range L

–40 to 150

ºC

Maximum Junction Temperature

165

ºC

Storage Temperature

–65 to 170

ºC

Terminal List Table

Number

Name

1

VCC

2

VOUT

3

TEST

4

GND

Description (continued)

Product Selection Guide

Part Number

Output Switching

Switchpoints

Symmetry

Increasing

Decreasing

(G)

(G)

(G)

(G)

(G)

A1421LK-T

Low (On) to

High (Off)

High (Off) to

Low (On)

15

0

15

15

7.5

Bulk, 500

pieces/bag

A1422LK-T

High (Off) to

Low (On)

Low (On) to

High (Off)

15

–15

0

0

0

A1423LK-T

High (Off) to

Low (On)

Low (On) to

High (Off)

65

–65

0

0

0

2

34

1

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