ATS675LSETN-HT-T Allegro, ATS675LSETN-HT-T Datasheet - Page 11

• Manufacturer Part Number: ATS675LSETN-HT-T
• Manufacturer: Allegro

ATS675LSE
Magnetic Profile
In order to establish the proper operating specification for a par-
ticular sensor device and target system, a systematic evaluation
of the magnetic circuit should be performed. The first step is the
generation of a magnetic map of the target. By using a calibrated
device, a magnetic profile of the system is made. Figure 11 is a
magnetic map of the 8X reference target.
Figure 11. Magnetic Data for the 8X Reference Target and SE package. Flux
density measurements are relative to the baseline magnetic field.
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Air Gap Versus Magnetic Field, Reference Target 8X with SE Package
Optimized for Automotive Cam Sensing Applications
Tooth
Valley
Magnetic Map, Reference Target 8X with SE Package
1.0
60
Sensor and Target Evaluation
120
2.0
Target Rotation (°)
AG (mm)
180
3.0
Self-Calibrating TPOS Speed Sensor
A pair of curves can be derived from this map data, and be used
to describe the tooth and valley magnetic field strength, B, versus
the size of the air gap, AG. This allows determination of the mini-
mum amount of magnetic flux density that guarantees operation
of the sensor, so the system designer can determine the maximum
allowable AG for the sensor and target system. One can also
determine the TPOS air gap capabilities of the sensor by compar-
ing the minimum tooth signal to the maximum valley signal.
240
4.0
300
5.0
115 Northeast Cutoff
1.508.853.5000; www.allegromicro.com
Allegro MicroSystems, Inc.
Worcester, Massachusetts 01615-0036 U.S.A.
360
6.0
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