SNOSD15B December 2016  – April 2017 LDC2112 , LDC2114

PRODUCTION DATA. 

  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. 6.6Digital Interface
    7. 6.7I2C Interface
    8. 6.8Typical Characteristics
  7. Detailed Description
    1. 7.1Overview
    2. 7.2Functional Block Diagram
    3. 7.3Feature Description
      1. 7.3.1Multi-Channel and Single-Channel Operation
      2. 7.3.2Button Output Interfaces
      3. 7.3.3Programmable Button Sensitivity
      4. 7.3.4Baseline Tracking
      5. 7.3.5Integrated Button Algorithms
      6. 7.3.6I2C Interface
        1. 7.3.6.1Selectable I2C Address (LDC2112 Only)
        2. 7.3.6.2I2C Interface Specifications
        3. 7.3.6.3I2C Bus Control
    4. 7.4Device Functional Modes
      1. 7.4.1Normal Power Mode
      2. 7.4.2Low Power Mode
      3. 7.4.3Configuration Mode
    5. 7.5Register Maps
      1. 7.5.1Individual Register Listings
        1. 7.5.1.1Gain Table for Registers GAIN0, GAIN1, GAIN2, and GAIN3
  8. Application and Implementation
    1. 8.1Application Information
      1. 8.1.1 Theory of Operation
      2. 8.1.2 Designing Sensor Parameters
      3. 8.1.3 Setting COM Pin Capacitor
      4. 8.1.4 Defining Power-On Timing
      5. 8.1.5 Configuring Button Scan Rate
      6. 8.1.6 Programming Button Sampling Window
      7. 8.1.7 Scaling Frequency Counter Output
      8. 8.1.8 Setting Button Triggering Threshold
      9. 8.1.9 Tracking Baseline
      10. 8.1.10Mitigating False Button Detections
        1. 8.1.10.1Eliminating Common-Mode Change (Anti-Common)
        2. 8.1.10.2Resolving Simultaneous Button Presses (Max-Win)
        3. 8.1.10.3Overcoming Case Twisting (Anti-Twist)
        4. 8.1.10.4Mitigating Metal Deformation (Anti-Deform)
      11. 8.1.11Reporting Interrupts for Button Presses and Error Conditions
      12. 8.1.12Estimating Supply Current
    2. 8.2Typical Application
      1. 8.2.1Touch Button Design
        1. 8.2.1.1Design Requirements
        2. 8.2.1.2Detailed Design Procedure
        3. 8.2.1.3Application Curves
  9. Power Supply Recommendations
  10. 10Layout
    1. 10.1Layout Guidelines
    2. 10.2Layout Example
    3. 10.3DSBGA Light Sensitivity
  11. 11Device and Documentation Support
    1. 11.1Documentation Support
      1. 11.1.1Related Documentation
    2. 11.2Related Links
    3. 11.3Receiving Notification of Documentation Updates
    4. 11.4Community Resources
    5. 11.5Trademarks
    6. 11.6Electrostatic Discharge Caution
    7. 11.7Export Control Notice
    8. 11.8Glossary
  12. 12Mechanical, Packaging, and Orderable Information

Features

  • Low Power Consumption:
    • One Button: 6 µA at 0.625 SPS
    • Two Buttons: 72 µA at 20 SPS
  • Configurable Button Scan Rates:
    • 0.625 SPS to 80 SPS
  • Force Level Measurement of Touch Buttons
  • Independent Channel Operation:
    • Two Channels for LDC2112
    • Four Channels for LDC2114
  • Integrated Algorithms to Enable:
    • Adjustable Force Threshold per Button
    • Environmental Shift Compensation
    • Simultaneous Button Press Detection
  • Supports Independent Operation without MCU
  • Robust EMI Performance:
    • Allows for CISPR 22 and CISPR 24 Compliance
  • Operating Voltage Range: 1.8 V ± 5%
  • Temperature Range: –40 °C to +85 °C
  • Interface:
    • I2C
    • Dedicated Logic Output per Channel

Applications

    Touch Buttons and Force Level Measurements on Different Materials, Including Metal, Plastic, and Glass for:

  • Consumer Electronics:
    • Smartphones
    • Smart Watches and Other Wearable Devices
    • Smart Speakers
    • Tablets/PCs
    • Virtual Reality Headsets
    • Sound Bars
  • Industrial Applications:
    • Televisions
    • Handheld Devices
    • Home Appliances
    • HMI Panels and Keypads

Description

Inductive sensing technology enables touch button design for human machine interface (HMI) on a wide variety of materials such as metal, glass, plastic, and wood, by measuring small deflections of conductive targets. The sensor for an inductive touch system is a coil that can be implemented on a small PCB located behind the panel and protected from the environment. Inductive sensing solution is insensitive to humidity or non-conductive contaminants such as oil and dirt. It is able to automatically correct for any deformation in the conductive targets.

The LDC2112/LDC2114 is a multi-channel low-noise inductance to digital converter with integrated algorithms to implement inductive touch applications. The device employs an innovative LC resonator that offers high rejection of noise and interference. The LDC2112/LDC2114 can reliably detect material deflections of less than 200 nm.

The LDC2112/LDC2114 includes an ultra-low power mode intended for power on/off buttons in battery powered applications.

The LDC2112/LDC2114 is available in a 16-pin DSBGA or TSSOP package. The 0.4 mm pitch DSBGA package has a very small 1.6 × 1.6 mm nominal body size with a maximum height of 0.4 mm. The 0.65 mm pitch TSSOP package has a 5.0 × 4.4 mm nominal body size with a maximum height of 1.2 mm.

Device Information(1)

PART NUMBERPACKAGEBODY SIZE (NOM)
LDC2112/LDC2114DSBGA (16)1.6 mm × 1.6 mm
LDC2112/LDC2114TSSOP (16)5.0 mm × 4.4 mm
  1. For all available packages, see the orderable addendum at the end of the data sheet.

Simplified Schematic

LDC2112 LDC2114 ldc2114-simplified-schematic-ldc2114-version-snosd15.gif