SNOSCZ7B December   2015  – April 2024 LDC0851

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  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 Support Resources
    4. 8.4 Trademarks
    5. 8.5 Electrostatic Discharge Caution
    6. 8.6 Glossary
  10. 9 Revision History
  11. 10Mechanical, Packaging, and Orderable Information

Package Options

Mechanical Data (Package|Pins)
Thermal pad, mechanical data (Package|Pins)
Orderable Information

6.1 Overview

The LDC0851 is an inductance comparator with push/pull output. It utilizes a sensing coil and a reference coil to determine the relative inductance in a system. The push/pull output (OUT) switches low when the sense inductance drops below the reference and returns high when the reference inductance is higher than the sense inductance. Matching the sense and reference coils is important to maintain a consistent switching distance over temperature and to compensate for other environmental factors. The LDC0851 features internal hysteresis to prevent false switching due to noise or mechanical vibration at the switching threshold. The switching threshold is set by the sensor characteristics and proximity to conductive objects, which is considered Basic Operation Mode described further in section Basic Operation Mode. The LDC0851 also features a Threshold Adjust Mode where an offset is subtracted from the reference inductance to change the effective switching point as described in section Threshold Adjust Mode.

The sensing coil is connected across the LSENSE and LCOM pins and the reference coil is connected across the LREF and LCOM pins. A sensor capacitor is connected from LCOM to GND to set the sensor oscillation frequency. The sensor capacitor is common to both LSENSE and LREF making the inductance measurement differential.