SLYA036B July   2018  – November 2021 DRV5053 , DRV5053-Q1 , DRV5055 , DRV5055-Q1 , DRV5056 , DRV5056-Q1 , DRV5057 , DRV5057-Q1

 

  1.   Trademarks
  2. 1Introduction
  3. 2Overview
    1. 2.1 Types of Magnetization
    2. 2.2 Types of Magnets
  4. 3Device Descriptions
    1. 3.1 2.5-V to 38-V, Bipolar Hall Effect Sensor Family: DRV5053 and DRV5053-Q1
    2. 3.2 High-Accuracy, 3.3-V or 5-V, Ratiometric, Bipolar Hall Effect Sensor Family: DRV5055 and DRV5055-Q1
    3. 3.3 High-Accuracy, 3.3-V or 5-V, Ratiometric, Unipolar Hall Effect Sensor Family: DRV5056 and DRV5056-Q1
  5. 4Methods
    1. 4.1 Uncalibrated Implementations
      1. 4.1.1 Overview
        1. 4.1.1.1 General Implementation
        2. 4.1.1.2 Preferred Magnet Types
        3. 4.1.1.3 General Accuracy and Resolution
        4. 4.1.1.4 Considerations
      2. 4.1.2 One Bipolar Sensor, Uncalibrated
        1. 4.1.2.1 Specific Implementation
        2. 4.1.2.2 Calculating Region
        3. 4.1.2.3 Accuracy
      3. 4.1.3 Two Bipolar Sensors 90° Apart, Uncalibrated
        1. 4.1.3.1 Specific Implementation
        2. 4.1.3.2 Calculating Region
        3. 4.1.3.3 Accuracy
      4. 4.1.4 Two Bipolar Sensors n° Apart, Uncalibrated
        1. 4.1.4.1 Specific Implementation
        2. 4.1.4.2 Calculating Region
        3. 4.1.4.3 Accuracy
      5. 4.1.5 Three or More Bipolar Sensors, Uncalibrated
        1. 4.1.5.1 Specific Implementation
        2. 4.1.5.2 Calculating Region
        3. 4.1.5.3 Accuracy
    2. 4.2 Peak Calibrated Implementations
      1. 4.2.1 Overview
        1. 4.2.1.1 General Implementation
        2. 4.2.1.2 Preferred Magnet Types
        3. 4.2.1.3 General Accuracy and Resolution
        4. 4.2.1.4 Considerations
      2. 4.2.2 One Bipolar Sensor, Peak Calibrated
        1. 4.2.2.1 Specific Implementation
        2. 4.2.2.2 Calculating Angle
        3. 4.2.2.3 Accuracy
      3. 4.2.3 Two Bipolar Sensors 90° Apart, Peak Calibrated
        1. 4.2.3.1 Specific Implementation
        2. 4.2.3.2 Calculating Angle
        3. 4.2.3.3 Accuracy
    3. 4.3 Lookup Table Calibration Implementations
      1. 4.3.1 Overview
        1. 4.3.1.1 General Implementation
        2. 4.3.1.2 Preferred Magnet Types
        3. 4.3.1.3 General Accuracy and Resolution
        4. 4.3.1.4 Considerations
      2. 4.3.2 One Bipolar Sensor, Lookup Table Calibrated
        1. 4.3.2.1 Specific Implementation
        2. 4.3.2.2 Calculating Angle
        3. 4.3.2.3 Accuracy
      3. 4.3.3 Two Bipolar Sensors ≈ 90° Apart, Lookup Table Calibrated
        1. 4.3.3.1 Specific Implementation
        2. 4.3.3.2 Calculating Angle
        3. 4.3.3.3 Accuracy
    4. 4.4 Peak Calibrated Plus Lookup Table Hybrid
      1. 4.4.1 Overview
        1. 4.4.1.1 General Implementation
        2. 4.4.1.2 Preferred Magnet Types
        3. 4.4.1.3 General Accuracy and Resolution
        4. 4.4.1.4 Considerations
      2. 4.4.2 One Bipolar Sensor, Hybrid Calibrated
        1. 4.4.2.1 Specific implementation
        2. 4.4.2.2 Calculating Angle
        3. 4.4.2.3 Accuracy
      3. 4.4.3 Two Bipolar Sensors 90° Apart, Hybrid Calibrated (Recommended High Accuracy Method)
        1. 4.4.3.1 Specific Implementation
        2. 4.4.3.2 Calculating Angle
        3. 4.4.3.3 Accuracy
  6. 5References
  7. 6Revision History

4.2.1.4 Considerations

  • The magnet must be oriented to align the degree output to the desired physical location.
  • The sensors and magnet must be placed so that the sensor voltage output is not clipped or railed at either the north or south pole.
  • If writing code that uses both the arctan2 and arcsin functions, consider using the identity in Equation 2. This identity saves on program space because the arctan2 function already uses the arctan function.
    Equation 2. arcsin(x)=2×arctan(x1+1-x2)
  • Most arctan2 and arcsin functions output the angle in radians. The angle can be converted to degrees using Equation 3.
    Equation 3. A°=Ar×180π
  • While a ±90° range is possible with one sensor, the voltage measurement accuracy and sensor noise limit the angle to a value less than ±90°.