SLYA048B March   2020  – June 2021 FDC1004 , FDC1004-Q1 , FDC2112 , FDC2112-Q1 , FDC2114 , FDC2114-Q1 , FDC2212 , FDC2212-Q1 , FDC2214 , FDC2214-Q1 , LDC0851 , LDC1001 , LDC1041 , LDC1051 , LDC1101 , LDC1312 , LDC1312-Q1 , LDC1314 , LDC1314-Q1 , LDC1612 , LDC1612-Q1 , LDC1614 , LDC1614-Q1 , LDC2112 , LDC2114 , LDC3114 , LDC3114-Q1

 

  1.   Trademarks
  2. 1Inductive and Capacitive Theory of Operation
    1. 1.1 Inductive Sensing Theory of Operation
    2. 1.2 Capacitive Sensing Theory of Operation
  3. 2FDC: Capacitive Level Sensing
    1. 2.1 Capacitive Technology Benefits in Liquid Level Sensing
    2. 2.2 Getting Started With Capacitive Liquid Level Sensing
    3. 2.3 Device Selection
    4. 2.4 Design Challenges and Additional Collateral
  4. 3LDC: Inductive Touch Buttons
    1. 3.1 Inductive Technology Benefits in Buttons
    2. 3.2 Getting Started With Inductive Buttons
    3. 3.3 Device Selection
    4. 3.4 Design Challenges and Additional Collateral
  5. 4LDC: Incremental Encoder and Event Counting
    1. 4.1 Inductive Technology Benefits in Incremental Encoders
    2. 4.2 Getting Started With an Inductive Incremental Encoder
    3. 4.3 Device Recommendations
    4. 4.4 Design Challenges and Additional Collateral
  6. 5LDC: Metal Proximity Sensor
    1. 5.1 Inductive Technology Benefits in Metal Proximity Detection
    2. 5.2 Criteria to Consider when Choosing Inductive Sensing for Metal Proximity Applications
      1. 5.2.1 Metal Target Movement in Relation to Inductive Coil
      2. 5.2.2 Sensing Distance
      3. 5.2.3 Size and Shape of Metal Target
      4. 5.2.4 Speed (Sample Rate versus Resolution)
      5. 5.2.5 Environmental Compensation
    3. 5.3 Getting Started With Inductive Metal Proximity Sensing
    4. 5.4 Device Recommendations
    5. 5.5 Design Challenges and Additional Collateral
  7. 6Revision History

2.3 Device Selection

The FDC1004 is the device of choice for liquid level sensing due to its integrated active shield drivers.

GUID-8ADF0C27-4BA3-4356-A95A-D3B68DD1E0CD-low.gif Figure 2-2 FDC1004 for Liquid Level Measurements

Key FDC1004 Parameters for Liquid Level Sensing:

  • Active shield driver that can help focus sensing direction of a capacitive sensor and reduce interference from unintended targets.
  • Four independent differential channels in one package enables a small footprint solution for differential and ratiometric measurements:
    • Level sensor
    • Reference sensor
    • Environmental Sensor to compensate for environmental changes (due to temperature, humidity, stress on container, and so forth)
  • Parasitic capacitance compensation up to 100 pF for each channel allowing compensation for external interference from long signal paths
  • High resolution that can enable less than 1-mm accuracy