Two-Wire True Zero Speed Miniature Differential

Peak-Detecting Gear Tooth Sensor with Continuous Calibration

ATS642LSH

ATS642LSH-DS, Rev. 1

Engineering samples available on a limited basis. Contact your local

sales or applications support office for additional information.

Description

TheATS642LSH is an optimized Hall effect sensing integrated

circuit and magnet combination that provides a user-friendly

solution for true zero-speed digital gear-tooth sensing in two-

wire applications. The sensor consists of a single-shot molded

plastic package that includes a samarium cobalt magnet, a

pole piece, and a Hall effect IC that has been optimized to the

magnetic circuit. This small package, with optimized two-wire

leadframe, can be easily assembled and used in conjunction

with a wide variety of gear shapes and sizes.

The integrated circuit incorporates a dual element Hall effect

sensor and signal processing that switches in response to

differential magnetic signals created by ferrous gear teeth.

The circuitry contains a sophisticated digital circuit to reduce

magnet and system offsets, to calibrate the gain for air gap

independent switchpoints, and to achieve true zero-speed

operation. Signal optimization occurs at power-up through

the combination of offset and gain adjust and is maintained

throughout the operating time with the use of a running mode

calibration. The running mode calibration allows immunity to

environmental effects such as microoscillations of the target

or sudden air gap changes.

The regulated current output is configured for two wire

applications and the sensor is ideally suited for obtain-

Features and Benefits

▪ Running mode calibration for continuous optimization

▪ Single chip IC for high reliability

▪ Internal current regulator for 2-wire operation

▪ Small mechanical size (8 mm diameter × 5.5 mm depth)

▪ Precise duty cycle signal over operating temperature range

▪ Large operating air gaps

▪ Automatic Gain Control (AGC) for air gap independent

switchpoints

▪ Automatic Offset Adjustment (AOA) for signal processing

optimization

▪ True zero-speed operation

▪ Undervoltage lockout

▪ Wide operating voltage range

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Package: 4-pin Module (suffix SH)

Functional Block Diagram

Not to scale

VCC

Automatic Offset

Control

AOA DAC

Hall

Amplifier

AGC DAC

Gain

Tracking

DAC

Peak Hold

Gain Control

Internal Regulator

Test Signals

GND

Test