SNOSCZ5B June   2015  – October 2024 FDC2112 , FDC2114 , FDC2212 , FDC2214

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Device Comparison
  6. 5 Pin Configuration and Functions
  7. 6 Specifications
    1. 6.1 Absolute Maximum Ratings
    2. 6.2 ESD Ratings
    3. 6.3 Recommended Operating Conditions
    4. 6.4 Thermal Information
    5. 6.5 Electrical Characteristics
    6. 6.6 Timing Requirements
    7. 6.7 Switching Characteristics - I2C
    8. 6.8 Typical Characteristics
  8. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagrams
    3. 7.3 Feature Description
      1. 7.3.1 Clocking Architecture
      2. 7.3.2 Multi-Channel and Single-Channel Operation
      3. 7.3.3 Gain and Offset (FDC2112, FDC2114 Only)
      4. 7.3.4 Current Drive Control Registers
      5. 7.3.5 Device Status Registers
      6. 7.3.6 Input Deglitch Filter
    4. 7.4 Device Functional Modes
      1. 7.4.1 Start-Up Mode
      2. 7.4.2 Normal (Conversion) Mode
      3. 7.4.3 Sleep Mode
      4. 7.4.4 Shutdown Mode
        1. 7.4.4.1 Reset
    5. 7.5 Programming
      1. 7.5.1 I2C Interface Specifications
    6. 7.6 Register Maps
      1. 7.6.1  Register List
      2. 7.6.2  Address 0x00, DATA_CH0
      3. 7.6.3  Address 0x01, DATA_LSB_CH0 (FDC2212 / FDC2214 only)
      4. 7.6.4  Address 0x02, DATA_CH1
      5. 7.6.5  Address 0x03, DATA_LSB_CH1 (FDC2212 / FDC2214 only)
      6. 7.6.6  Address 0x04, DATA_CH2 (FDC2114, FDC2214 only)
      7. 7.6.7  Address 0x05, DATA_LSB_CH2 (FDC2214 only)
      8. 7.6.8  Address 0x06, DATA_CH3 (FDC2114, FDC2214 only)
      9. 7.6.9  Address 0x07, DATA_LSB_CH3 (FDC2214 only)
      10. 7.6.10 Address 0x08, RCOUNT_CH0
      11. 7.6.11 Address 0x09, RCOUNT_CH1
      12. 7.6.12 Address 0x0A, RCOUNT_CH2 (FDC2114, FDC2214 only)
      13. 7.6.13 Address 0x0B, RCOUNT_CH3 (FDC2114, FDC2214 only)
      14. 7.6.14 Address 0x0C, OFFSET_CH0 (FDC21112 / FDC2114 only)
      15. 7.6.15 Address 0x0D, OFFSET_CH1 (FDC21112 / FDC2114 only)
      16. 7.6.16 Address 0x0E, OFFSET_CH2 (FDC2114 only)
      17. 7.6.17 Address 0x0F, OFFSET_CH3 (FDC2114 only)
      18. 7.6.18 Address 0x10, SETTLECOUNT_CH0
      19. 7.6.19 Address 0x11, SETTLECOUNT_CH1
      20. 7.6.20 Address 0x12, SETTLECOUNT_CH2 (FDC2114, FDC2214 only)
      21. 7.6.21 Address 0x13, SETTLECOUNT_CH3 (FDC2114, FDC2214 only)
      22. 7.6.22 Address 0x14, CLOCK_DIVIDERS_CH0
      23. 7.6.23 Address 0x15, CLOCK_DIVIDERS_CH1
      24. 7.6.24 Address 0x16, CLOCK_DIVIDERS_CH2 (FDC2114, FDC2214 only)
      25. 7.6.25 Address 0x17, CLOCK_DIVIDERS_CH3 (FDC2114, FDC2214 only)
      26. 7.6.26 Address 0x18, STATUS
      27. 7.6.27 Address 0x19, ERROR_CONFIG
      28. 7.6.28 Address 0x1A, CONFIG
      29. 7.6.29 Address 0x1B, MUX_CONFIG
      30. 7.6.30 Address 0x1C, RESET_DEV
      31. 7.6.31 Address 0x1E, DRIVE_CURRENT_CH0
      32. 7.6.32 Address 0x1F, DRIVE_CURRENT_CH1
      33. 7.6.33 Address 0x20, DRIVE_CURRENT_CH2 (FDC2114 / FDC2214 only)
      34. 7.6.34 Address 0x21, DRIVE_CURRENT_CH3 (FDC2114 / FDC2214 only)
      35. 7.6.35 Address 0x7E, MANUFACTURER_ID
      36. 7.6.36 Address 0x7F, DEVICE_ID
  9. 8 Application and Implementation
    1. 8.1 Application Information
      1. 8.1.1 Sensor Configuration
      2. 8.1.2 Shield
      3. 8.1.3 Power-Cycled Applications
      4. 8.1.4 Inductor Self-Resonant Frequency
      5. 8.1.5 Application Curves
    2. 8.2 Typical Application
      1. 8.2.1 Schematic
      2. 8.2.2 Design Requirements
      3. 8.2.3 Detailed Design Procedure
        1. 8.2.3.1 Recommended Initial Register Configuration Values
      4. 8.2.4 Application Curve
    3. 8.3 Best Design Practices
    4. 8.4 Power Supply Recommendations
    5. 8.5 Layout
      1. 8.5.1 Layout Guidelines
      2. 8.5.2 Layout Example
  10. 9 Device and Documentation Support
    1. 9.1 Receiving Notification of Documentation Updates
    2. 9.2 Support Resources
    3. 9.3 Trademarks
    4. 9.4 Electrostatic Discharge Caution
    5. 9.5 Glossary
  11. 10Revision History
  12. 11Mechanical, Packaging, and Orderable Information

Package Options

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

8.2.3 Detailed Design Procedure

In capacitive sensing systems, the design of the sensor plays an important role in determining system performance and capabilities. In most cases the sensor is simply a metal plate that can be designed on the PCB.

The sensor used in this example is implemented with a two-layer PCB. On the top layer, which faces the tank, there are the 3 electrodes (Reference Environmental, Reference Liquid, and Level) with a ground plane surrounding the electrodes.

Depending on the shape of the container, the FDC can be located on the sensor PCB to minimize the length of the traces between the input channels and the sensors. In case the shape of the container or other mechanical constraints do not allow having the sensors and the FDC on the same PCB, the traces which connect the channels to the sensor need to be shielded with the appropriate shield.