SNOSCY9 December 2014 LDC1612 , LDC1614


  1. Features
  2. Applications
  3. Description
  4. Revision History
  5. Pin Configuration and Functions
  6. Specifications
    1. 6.1Absolute Maximum Ratings
    2. 6.2ESD Ratings
    3. 6.3Recommended Operating Conditions
    4. 6.4Thermal Information
    5. 6.5Electrical Characteristics
    6. 6.6Switching Characteristics - I2C
    7. 6.7Typical Characteristics
  7. Detailed Description
    1. 7.1Overview
    2. 7.2Functional Block Diagram
    3. 7.3Feature Description
      1. 7.3.1Clocking Architecture
      2. 7.3.2Multi-Channel and Single Channel Operation
      3. 7.3.3Current Drive Control Registers
      4. 7.3.4Device Status Registers
      5. 7.3.5Input Deglitch Filter
    4. 7.4Device Functional Modes
      1. 7.4.1Startup Mode
      2. 7.4.2Normal (Conversion) Mode
      3. 7.4.3Sleep Mode
      4. 7.4.4Shutdown Mode
    5. 7.5Programming
      1. 7.5.1I2C Interface Specifications
    6. 7.6Register Maps
      1. 7.6.1 Register List
      2. 7.6.2 Address 0x00, DATA_MSB_CH0
      3. 7.6.3 Address 0x01, DATA_LSB_CH0
      4. 7.6.4 Address 0x02, DATA_MSB_CH1
      5. 7.6.5 Address 0x03, DATA_LSB_CH1
      6. 7.6.6 Address 0x04, DATA_MSB_CH2 (LDC1614 only)
      7. 7.6.7 Address 0x05, DATA_LSB_CH2 (LDC1614 only)
      8. 7.6.8 Address 0x06, DATA_MSB_CH3 (LDC1614 only)
      9. 7.6.9 Address 0x07, DATA_LSB_CH3 (LDC1614 only)
      10. 7.6.10Address 0x08, RCOUNT_CH0
      11. 7.6.11Address 0x09, RCOUNT_CH1
      12. 7.6.12Address 0x0A, RCOUNT_CH2 (LDC1614 only)
      13. 7.6.13Address 0x0B, RCOUNT_CH3 (LDC1614 only)
      14. 7.6.14Address 0x0C, OFFSET_CH0
      15. 7.6.15Address 0x0D, OFFSET_CH1
      16. 7.6.16Address 0x0E, OFFSET_CH2 (LDC1614 only)
      17. 7.6.17Address 0x0F, OFFSET_CH3 (LDC1614 only)
      18. 7.6.18Address 0x10, SETTLECOUNT_CH0
      19. 7.6.19Address 0x11, SETTLECOUNT_CH1
      20. 7.6.20Address 0x12, SETTLECOUNT_CH2 (LDC1614 only)
      21. 7.6.21Address 0x13, SETTLECOUNT_CH3 (LDC1614 only)
      22. 7.6.22Address 0x14, CLOCK_DIVIDERS_CH0
      23. 7.6.23Address 0x15, CLOCK_DIVIDERS_CH1
      24. 7.6.24Address 0x16, CLOCK_DIVIDERS_CH2 (LDC1614 only)
      25. 7.6.25Address 0x17, CLOCK_DIVIDERS_CH3 (LDC1614 only)
      26. 7.6.26Address 0x18, STATUS
      27. 7.6.27Address 0x19, ERROR_CONFIG
      28. 7.6.28Address 0x1A, CONFIG
      29. 7.6.29Address 0x1B, MUX_CONFIG
      30. 7.6.30Address 0x1C, RESET_DEV
      31. 7.6.31Address 0x1E, DRIVE_CURRENT_CH0
      32. 7.6.32Address 0x1F, DRIVE_CURRENT_CH1
      33. 7.6.33Address 0x20, DRIVE_CURRENT_CH2 (LDC1614 only)
      34. 7.6.34Address 0x21, DRIVE_CURRENT_CH3 (LDC1614 only)
      35. 7.6.35Address 0x7E, MANUFACTURER_ID
      36. 7.6.36Address 0x7F, DEVICE_ID
  8. Application and Implementation
    1. 8.1Application Information
      1. 8.1.1Theory of Operation
        1. Objects in an EM Field
        2. Resonators
    2. 8.2Typical Application
      1. 8.2.1Design Requirements
      2. 8.2.2Detailed Design Procedure
      3. 8.2.3Recommended Initial Register Configuration Values
      4. 8.2.4Application Curves
      5. 8.2.5Inductor Self-Resonant Frequency
  9. Power Supply Recommendations
  10. 10Layout
    1. 10.1Layout Guidelines
    2. 10.2Layout Example
  11. 11Device and Documentation Support
    1. 11.1Device Support
      1. 11.1.1Development Support
    2. 11.2Documentation Support
      1. 11.2.1Related Documentation
    3. 11.3Related Links
    4. 11.4Trademarks
    5. 11.5Electrostatic Discharge Caution
    6. 11.6Glossary
  12. 12Mechanical, Packaging, and Orderable Information

1 Features

  • Easy-to-use – minimal configuration required
  • Measure up to 4 sensors with one IC
  • Multiple channels support environmental and aging compensation
  • Multi-channel remote sensing provides lowest system cost
  • Pin-compatible medium and high-resolution options
    • LDC1312/4: 2/4-ch 12-bit LDC
    • LDC1612/4: 2/4-ch 28-bit LDC
  • Sensing range beyond two coil diameters
  • Supports wide sensor frequency range of 1kHz to 10MHz
  • Power consumption:
    • 35 µA Low Power Sleep Mode
    • 200 nA Shutdown Mode
  • 3.3V operation
  • Support internal or external reference clock
  • Immune to DC magnetic fields and magnets

2 Applications

  • Knobs in consumer, appliances, and automotive
  • Linear and rotational encoders
  • Buttons in home electronics, wearables, manufacturing, and automotive
  • Keypads in manufacturing and appliances
  • Slider buttons in consumer products
  • Metal detection in industrial and automotive
  • POS and EPOS
  • Flow meters in consumer and appliances

3 Description

The LDC1612 and LDC1614 are 2- and 4-channel, 28-bit inductance to digital converters (LDCs) for inductive sensing solutions. With multiple channels and support for remote sensing, the LDC1612 and LDC1614 enable the performance and reliability benefits of inductive sensing to be realized at minimal cost and power. The products are easy to use, only requiring that the sensor frequency be within 1 kHz and 10 MHz to begin sensing. The wide 1 kHz to 10 MHz sensor frequency range also enables use of very small PCB coils, further reducing sensing solution cost and size.

The high resolution channels allow for a much larger sensing range, maintaining good performance beyond two coil diameters. Well-matched channels allow for differential and ratiometric measurements, which enable designers to use one channel to compensate their sensing for environmental and aging conditions such as temperature, humidity, and mechanical drift.

Given their ease of use, low power, and low system cost these products enable designers to greatly improve performance, reliability, and flexibility over existing sensing solutions and to introduce brand new sensing capabilities to products in all markets, especially consumer and industrial applications.

These devices are easily configured via an I2C interface. The two-channel LDC1612 is available in a WSON-12 package and the four-channel LDC1614 is available in a WQFN-16 package.

Device Information(1)

LDC1612WSON-124 mm × 4 mm
LDC1614WQFN-164 mm × 4 mm
  1. For all available packages, see the orderable addendum at the end of the datasheet.

Simplified Schematic


Measurement Precision vs. Target Distance