1. Product Overview: ATS665LSG

️· Type: Linear Hall-Effect Sensor
️· Application: Primarily designed for gear-tooth sensing (speed and position) and similar applications requiring linear output related to magnetic field strength.
️· Key Feature: Adaptive self-calibration (updates its zero-point) to compensate for variations in air gap.

2. Key Features & Technologies

️· Linear Output: Provides an analog voltage output proportional to the magnetic field.
️· Adaptive Calibration: Automatically adjusts to changing air gaps, maintaining accuracy. Requires re-powering after significant air gap changes for optimal performance.
️· High Sensitivity: Enables detection of small magnetic variations.
️· Temperature Compensation: Integrated circuitry minimizes the impact of temperature changes.
️· Output Polarity Selection: The output polarity can be programmed by externally applying a magnetic field.

3. Operating Conditions & Electrical Characteristics

️· Supply Voltage (Vcc): Dependent on package power derating, see section 13
️· Quiescent Current: Typically 7.0 mA, but varies with supply voltage and operating conditions. Refer to the Characteristic Data section for details.
️· Output Voltage Swing: Approximately ±4.5 V (with ±5 V supply).
️· Magnetic Field Sensitivity: The specific sensitivity varies depending on the device version.
️· Operating Temperature: -40°C to 150°C (junction temperature).
️· Storage Temperature: -65°C to 170°C

4. Design Recommendations

️· Target Design:
- Tooth width > 2 mm
- Valley width > 2 mm
- Valley depth > 2 mm
- Gear thickness > 3 mm
- Target material: Low-carbon steel (or equivalent for stamped geometries).
️· Air Gap Considerations: The adaptive calibration is beneficial, but *significant* air gap changes require re-powering the sensor.

5. Power De-Rating & Thermal Management

️· Junction Temperature (Tj): Crucial to monitor and stay within limits. Tj = Ta + ΔT (ambient + temperature rise).
️· Maximum Junction Temperature (Tjmax): 165°C.
️· Thermal Resistance (Rθja): 126°C/W (package-dependent).
️· Power Dissipation: Limit power dissipation to avoid overheating and ensure reliable operation.
️· Ambient Temperature Limit: The document provides calculations to determine the maximum ambient temperature based on power dissipation and thermal resistance.

6. Characteristic Data

️· This section contains tables detailing specific electrical characteristics (sensitivity, quiescent current, voltage swing, etc.) for different operating conditions and package types. Refer to this data for precise values.

7. Package Information

️· The document includes a package drawing, which is essential for mechanical design and assembly.

8. Related Documents

️· Links to relevant documentation on Allegro Microsystems’ website are provided.

Summary Table

Feature	Description
Sensor Type	Linear Hall-Effect
Primary Application	Gear Tooth Sensing
Adaptive Calibration	Yes, requires re-powering for significant air gap changes
Operating Temperature	-40°C to 150°C (junction)
Power Dissipation	Limited by thermal resistance and ambient temperature
Package	See package drawing in document
Website	[www.allegromicro.com](http://www.allegromicro.com/)

To effectively use this document, it's crucial to:

️· Review the 'Characteristic Data' section: This provides specific electrical values for the device.
️· Pay attention to thermal management: Ensure proper heat sinking or ambient temperature limits are observed to avoid overheating.
️· Consult Allegro's website: For more detailed information and application notes.