Self-Calibrating, Zero-Speed Differential

Gear Tooth Sensor with Continuous Update

ATS643LSH

4

Allegro MicroSystems, Inc.

115 Northeast Cutoff, Box 15036

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

www.allegromicro.com

OPERATING CHARACTERISTICS

Characteristic

Symbol

Test Conditions

Min.

Typ.

Max.

Units

SWITCHPOINT CHARACTERISTICS

Rotation Speed

Reference Target 60-0

0

–

12,000

rpm

Bandwidth

BW

Equivalent to f – 3dB

25

40

–

kHz

Operate Point

% of peak to peak referenced from PDAC to NDAC,

–65–

%

Release Point

% of peak to peak referenced from PDAC to NDAC,

–35–

%

Initial Calibration Period

Quantity of rising output (current) edges required for

accurate edge detection

–

–

3

Edge

AGC Calibration Disable

Quantity of rising output (current) edges used for

calibrating AGC

–

–

3

Edge

Start Mode Hysteresis

–

175

–

mV

DAC CHARACTERISTICS

Dynamic Offset Cancellation

–

±60

–

G

Tracking Data Resolution

Quantity of bits available for PDAC/NDAC tracking of

both positive and negative signal peaks

–9–

Bit

FUNCTIONAL CHARACTERISTICS

AG

ΔDC within specification

0.5

–

2.5

mm

Maximum Operable Air Gap

Output switching (no missed edges); ΔDC not

guaranteed

–

–

2.75

mm

Duty Cycle Variation

ΔDC

Wobble < 0.5 mm, AG within specification

–

–

±10

%

Input Signal Range

Sig

ΔDC within specification

40

–

1400

G

Minimum Operable Input Signal

Output switching (no missed edges); ΔDC not

guaranteed

30

–

–

G

of the bypass capacitor, if one is used.

characterized. The field available from the reference target is given in the reference target parameter section of the datasheet.