ATS642 Datasheet, PDF (1/16 Pages) Allegro MicroSystems – Two-Wire True Zero Speed Miniature Differential Peak-Detecting Gear Tooth Sensor with Continuous Calibration

ATS642LSH
Two-Wire True Zero Speed Miniature Differential
Peak-Detecting Gear Tooth Sensor with Continuous Calibration
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
Package: 4-pin Module (suffix SH)
Not to scale
Description
The ATS642LSH 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-
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Engineering samples available on a limited basis. Contact your local
sales or applications support office for additional information.
Functional Block Diagram
Hall
Amplifier
Gain
VCC
Automatic Offset
Control
AOA DAC
Tracking
DAC
Peak Hold
AGC DAC
Gain Control
ATS642LSH-DS, Rev. 1
Internal Regulator
Test Signals
GND
Test