JAJSUC2B December   2015  – April 2024 LDC0851

PRODUCTION DATA  

  1.   1
  2. 1 特長
  3. 2 アプリケーション
  4. 3 概要
  5. 4 Pin Configuration and Functions
  6. 5 Specifications
    1. 5.1 Absolute Maximum Ratings
    2. 5.2 ESD Ratings
    3. 5.3 Recommended Operating Conditions
    4. 5.4 Thermal Information
    5. 5.5 Electrical Characteristics
    6. 5.6 Interface Voltage Levels
    7. 5.7 Timing Requirements
    8. 5.8 Typical Characteristics
  7. 6 Detailed Description
    1. 6.1 Overview
    2. 6.2 Functional Block Diagram
    3. 6.3 Feature Description
      1. 6.3.1 Basic Operation Mode
      2. 6.3.2 Threshold Adjust Mode
      3. 6.3.3 Setting the Threshold Adjust Values
      4. 6.3.4 Hysteresis
      5. 6.3.5 Conversion Time
      6. 6.3.6 Power-Up Conditions
    4. 6.4 Device Functional Modes
      1. 6.4.1 Shutdown Mode
      2. 6.4.2 Active Mode
  8. 7 Application and Implementation
    1. 7.1 Application Information
      1. 7.1.1 Sensor Design
        1. 7.1.1.1 Sensor Frequency
        2. 7.1.1.2 Sensor Design Procedure
    2. 7.2 Typical Application
      1. 7.2.1 Event Counting
        1. 7.2.1.1 Design Requirements
        2. 7.2.1.2 Detailed Design Procedure
        3. 7.2.1.3 Application Curves
      2. 7.2.2 Coarse Position Sensing
        1. 7.2.2.1 Design Requirements
        2. 7.2.2.2 Detailed Design Procedure
        3. 7.2.2.3 Application Curves
      3. 7.2.3 Low Power Operation
        1. 7.2.3.1 Design Requirements
        2. 7.2.3.2 Detailed Design Procedure
        3. 7.2.3.3 Application Curves
    3. 7.3 Power Supply Recommendations
    4. 7.4 Layout
      1. 7.4.1 Layout Guidelines
      2. 7.4.2 Layout Example
        1. 7.4.2.1 Side by Side Coils
        2. 7.4.2.2 Stacked Coils
  9. 8 Device and Documentation Support
    1. 8.1 Device Support
      1. 8.1.1 Development Support
    2. 8.2 Documentation Support
      1. 8.2.1 Related Documentation
    3. 8.3 サポート・リソース
    4. 8.4 Trademarks
    5. 8.5 静電気放電に関する注意事項
    6. 8.6 用語集
  10. 9 Revision History
  11. 10Mechanical, Packaging, and Orderable Information

6.3.1 Basic Operation Mode

The LDC0851 is configured for Basic Operation mode when the ADJ pin is tied to ground. Two identical coils should be used for LSENSE and LREF. The switching point occurs when the inductances of both coils are equal. Basic Operation mode can be used for a wide variety of applications including event counting, sliders, or proximity sensing. An example showing gear tooth counting can be found in section Event Counting.

For proximity sensing the switching point can be set by placing a conductive target at a fixed distance from the reference coil as shown in Figure 6-1. The output will switch when a conductive target approaches LSENSE and reaches the same distance set by the fixed reference target. For reliable and repeatable switching it is recommended to place the reference target at a distance less than 40% of the coil diameter from the reference coil.

LDC0851 Basic Operation Mode Diagram for Distance Sensing With Reference TargetFigure 6-1 Basic Operation Mode Diagram for Distance Sensing With Reference Target

In some systems adding a reference target at a fixed height to set the switching distance is not feasible. Therefore to set the switching distance a small amount of mismatch between the sense and reference coils can be introduced. To achieve the maximum switching distance the reference inductance should be approximately 0.4% less than the sense inductance as shown in Figure 6-2 below. The 0.4% mismatch will ensure that the output will switch off when the target is removed.

LDC0851 Basic Operation Mode Diagram for Distance Sensing With Mismatched CoilsFigure 6-2 Basic Operation Mode Diagram for Distance Sensing With Mismatched Coils