2

651LSH-DS

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

115 Northeast Cutoff, Box 15036

www.allegromicro.com

Allegro MicroSystems, Inc.

Two-Wire Self-Calibrating Differential Speed and Direction Sensor with Vibration Immunity

ATS651LSH

Functional Block Diagram

Current

Output

Adjust

GND

VCC

0.01μF

C

BYPASS

V+

Voltage

Regulator

TEST

Hall

Amp

PDAC

NDAC

Reference

Generator

& Updates

PThresh

NThresh

Threshold

Logic

(Recommended)

Speed

and

Direction

Logic

AGC

Offset

Adjust

Hall

Amp

PDAC

NDAC

Reference

Generator

& Updates

PThresh

NThresh

Threshold

Logic

AGC

Offset

Adjust

Typical Application Diagram

2

ATS651

1

3

4

0.01

μF

100

Ω

ECU

I

R

SENSE

C

SENSE

C

BYPASS

Note: Pins 2 and 3 may be connected to pin 4.