Description

The ATS616 gear-tooth sensor IC is a peak-detecting device

that uses automatic gain control and an integrated capacitor

to provide extremely accurate gear edge detection down to

low operating speeds. Each package consists of a high-tem-

perature plastic shell that holds together a samarium-cobalt

pellet, 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 technology used for this circuit is Hall-effect based.

The chip incorporates a dual-element Hall IC that switches

in response to differential magnetic signals created by fer-

romagnetic targets. The sophisticated processing circuitry

contains an A-to-D converter that self-calibrates (normal-

izes) 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. This easy-to-integrate

solution provides first-tooth detection and stable operation

to extremely low rpm. The ATS616 can be used as a replace-

ment for the ATS612LSB, eliminating the external peak-

holding capacitor needed by the ATS612LSB.

ATS616LSG-DS, Rev. 4

Features and Benefits

• Self-calibrating for tight timing accuracy

• First-tooth detection

• Immunity to air gap variation and system offsets

• Eliminates effects of signature tooth offsets

• Integrated capacitor provides analog peak and valley

information

• Extremely low timing-accuracy drift with temperature

changes

• Large air gap capability

• Small, integrated package

• Optimized magnetic circuit

• Undervoltage lockout (UVLO)

• Wide operating voltage range

Dynamic Self-Calibrating Peak-Detecting Differential

Hall Effect Gear Tooth Sensor IC

Package: 4-pin SIP (suffix SG)

Functional Block Diagram

Not to scale

ATS616LSG

Continued on the next page…

GND

VOUT

VCC

Voltage

Regulator

TEST

Hall

Amp

Reference

Generator

Gain

Current

Limit

(Recommended)

Hall

Amp

Track and

Hold

Track and

Hold

UVLO

Power-On

Logic

Tooth and Valley

Comparator