Dwg. AH-006

1

2

3

4

Pin 1 = Supply

Pin 2 = Output

Pin 3 = Capacitor

Pin 4 = Ground

continued next page…

DYNAMIC, SELF-CALIBRATING,

PEAK-DETECTING, DIFFERENTIAL

HALL-EFFECT GEAR-TOOTH SENSOR

The ATS612LSB gear-tooth sensor is a peak detecting device that

uses automatic gain control to provide extremely accurate gear edge

detection down to low operating speeds. Each sensor module consists

of a high-temperature plastic shell that holds together a samarium-

cobalt magnet, a pole piece, and a differential open-collector Hall IC

that has been optimized to the magnetic circuit. This small package

can be easily assembled and used in conjunction with a wide variety of

gear shapes and sizes.

The gear-sensing technology used for this sensor is Hall-effect

based. The sensor incorporates a dual-element Hall IC that switches in

response to differential magnetic signals created by ferrous targets.

The sophisticated processing circuitry contains a 5-bit A/D converter

that self-calibrates (normalizes) the internal gain of the device to

minimize the effect of air-gap variations. The patented peak-detecting

filter circuit eliminates magnet and system offsets and has the ability to

discriminate relatively fast changes such as those caused by tilt, gear

wobble, and eccentricities yet provides stable operation to extremely

low RPM.

These sensor systems are ideal for use in gathering speed, posi-

tion, and timing information using gear-tooth-based configurations. The

ATS612LSB is particularly suited to those applications that require

extremely accurate duty cycle control or accurate edge detection such

as in automotive crank shaft applications. The lower vibration sensitiv-

ity also makes this device extremely useful for transmission speed

sensing.

ATS612LSB: Large/small-tooth gear-position sensing —

crank angle, transmission speed, cam angle.

Always order by complete part number: ATS612LSB .

ABSOLUTE MAXIMUM RATINGS

over operating temperature range

Package Power Dissipation,

Operating Temperature Range,

* Operation at increased supply voltages with

external circuitry is described in Applications

Information. Devices for operation at increased

temperatures are available on special order.

† Output is current limited at 25 mA to 55 mA.

Continued operation in this mode can cause

excessive device heating and failure. See graph,

next page.

ATS612LSB