True Zero-Speed High-Accuracy

Gear Tooth Sensor IC

ATS668LSM

5

Allegro MicroSystems, LLC

115 Northeast Cutoff

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

1.508.853.5000; www.allegromicro.com

FUNCTIONAL CHARACTERISTICS

Characteristics

Symbol

Note

Min.

Typ.

Max.

Unit

POWER ON

Power-On State

POS

–

High

–

–

–

–

2

ms

AIR GAP

Operating Air Gap Range

Guaranteed to operate within specification

0.5

–

2.5

mm

Extended Air Gap Range

Switching only—not guaranteed to operate

within spec

2.5

–

3

mm

OFFSET

Dynamic Offset Cancellation

±60

–

–

G

CALIBRATION

Quantity of rising output edges required for

accurate edge detection

–

2

3

edge

SWITCHING

Operating Speed

0

–

12

kHz

Analog Signal Bandwidth

BW

15

20

–

kHz

Operate Point

OP

–

70

–

%

Release Point

RP

–

30

–

%

Output Duty Cycle

DC

AG = 0.5 mm to 2.5 mm, Pin 3 to 1 target rotation

39

–

52

%

AG = 2.5 mm to 3.0 mm, Pin 3 to 1 target rotation

39

–

56

%

1

Power-On Time includes the time required to complete the internal automatic offset adjust. DAC is then ready for peak acquisition.

2

achieved, including the possibility of missed output edges.

3

Figure 4: Definition of Terms for Switchpoints

Valley

Tooth

Forward

Reverse

+B

–B

+V

–V

t

100 %