ATS610LSC

DYNAMIC, PEAK-DETECTING,

DIFFERENTIAL HALL-EFFECT

GEAR-TOOTH SENSOR

115 Northeast Cutoff, Box 15036

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

DEVICE DESCRIPTION — Continued

Dwg. WH-011

V

OUT(SAT)

V

BB

OPERATE

RELEASE

OPERATE

RELEASE

0

Power-On Operation. The device will power on in the

OFF state (output high) irrespective of the magnetic field

condition. The power-on time of the circuit is no greater

than 5000

µs. The circuit is then ready to accurately

detect the first target edge that results in a HIGH-to-LOW

transition.

Under-Voltage Lockout. When the supply voltage is

is OFF and stays OFF irrespective of the state of the

magnetic field. This prevents false signals, which may be

caused by under-voltage conditions (especially during turn

on), from appearing at the output.

Output. The device output is an open-collector stage

capable of sinking 25 mA. An external pull-up (resistor) to

a supply voltage of not more than 18 V must be supplied.

Superior Performance. The ATS610LSC peak-detecting

differential gear-tooth sensor sub-assembly has several

advantages over conventional Hall-effect gear-tooth

sensors.

Differential vs. Single-Element Sensing. The differen-

tial Hall-element configuration is superior in most applica-

tions to the classical single-element gear-tooth sensor.

The single-element configuration commonly used

(Hall-effect sensor mounted on the face of a simple

permanent magnet) requires the detection of a small

signal (often <100 G) that is superimposed on a large

back-biased field, often 1500 G to 3500 G. For most

gear/target configurations, the back-biased field values

10

20

30

60

-2000

-5000

ANGLE OF TARGET ROTATION IN DEGREES

-2500

-4000

-4500

0

Dwg. GH-061-1

-3500

-3000

T

= 25

°C

A

50

40

TARGET

AIR GAP = 2.5 mm

AIR GAP = 2.0 mm

AIR GAP = 1.5 mm

AIR GAP = 0.5 mm

AIR GAP = 1.0 mm

Single-element flux maps

showing the impact of varying valley widths

change due to concentration effects, resulting in a varying

baseline with air gap, with valley widths, with eccentrici-

ties, and with vibration. The differential configuration

cancels the effects of the back-biased field and avoids

many of the issues presented by the single Hall element.

NOTE — 10 G = 1 mT, exactly.

10

20

30

60

1500

-1500

ANGLE OF TARGET ROTATION IN DEGREES

1000

-500

-1000

0

Dwg. GH-061

0

500

T

= 25

°C

A

50

40

TARGET

AIR GAP = 2.5 mm

AIR GAP = 2.0 mm

AIR GAP = 1.5 mm

AIR GAP = 0.5 mm

AIR GAP = 1.0 mm

Differential flux maps vs. air gaps