SNOSD01D May   2015  – October  2016 LDC1101

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Simplified Schematic
  5. 5 Revision History
  6. 6 Pin Configuration and Functions
  7. 7 Specifications
    1. 7.1 Absolute Maximum Ratings
    2. 7.2 ESD Ratings
    3. 7.3 Recommended Operating Conditions
    4. 7.4 Thermal Information
    5. 7.5 Electrical Characteristics
    6. 7.6 Digital Interface
    7. 7.7 Timing Requirements
    8. 7.8 Typical Characteristics
  8. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1 Sensor Driver
    4. 8.4 Device Functional Modes
      1. 8.4.1 Measurement Modes
      2. 8.4.2 RP+L Measurement Mode
        1. 8.4.2.1 RPMIN and RPMAX
        2. 8.4.2.2 Programmable Internal Time Constants
        3. 8.4.2.3 RP+L Mode Measurement Sample Rate
      3. 8.4.3 High Resolution L (LHR) Measurement Mode
      4. 8.4.4 Reference Count Setting
      5. 8.4.5 L-Only Measurement Operation
      6. 8.4.6 Minimum Sensor Frequency and Watchdog Setting
      7. 8.4.7 Low Power Modes
        1. 8.4.7.1 Shutdown Mode
        2. 8.4.7.2 Sleep Mode
      8. 8.4.8 Status Reporting
      9. 8.4.9 Switch Functionality and INTB Reporting
    5. 8.5 Programming
      1. 8.5.1 SPI Programming
    6. 8.6 Register Maps
      1. 8.6.1  Individual Register Listings
      2. 8.6.2  Register RP_SET (address = 0x01) [reset = 0x07]
      3. 8.6.3  Register TC1 (address = 0x02) [reset = 0x90]
      4. 8.6.4  Register TC2 (address = 0x03) [reset = 0xA0]
      5. 8.6.5  Register DIG_CONF (address = 0x04) [reset = 0x03]
      6. 8.6.6  Register ALT_CONFIG (address = 0x05) [reset = 0x00]
      7. 8.6.7  Register RP_THRESH_HI_LSB (address = 0x06) [reset = 0x00]
      8. 8.6.8  Register RP_THRESH_HI_MSB (address = 0x07) [reset = 0x00]
      9. 8.6.9  Register RP_THRESH_LO_LSB (address = 0x08) [reset = 0x00]
      10. 8.6.10 Register RP_THRESH_LO_MSB (address = 0x09) [reset = 0x00]
      11. 8.6.11 Register INTB_MODE (address = 0x0A) [reset = 0x00]
      12. 8.6.12 9.Register START_CONFIG (address = 0x0B) [reset = 0x01]
      13. 8.6.13 Register D_CONFIG (address = 0x0C) [reset = 0x00]
      14. 8.6.14 Register L_THRESH_HI_LSB (address = 0x16) [reset = 0x00]
      15. 8.6.15 Register L_THRESH_HI_MSB (address = 0x17) [reset = 0x00]
      16. 8.6.16 Register L_THRESH_LO_LSB (address = 0x18) [reset = 0x00]
      17. 8.6.17 Register L_THRESH_LO_MSB (address = 0x19) [reset = 0x00]
      18. 8.6.18 Register STATUS (address = 0x020 [reset = 0x00]
      19. 8.6.19 Register RP_DATA_LSB (address = 0x21) [reset = 0x00]
      20. 8.6.20 Register RP_DATA_MSB (address = 0x22) [reset = 0x00]
      21. 8.6.21 Register L_DATA_LSB (address = 0x23) [reset = 0x00]
      22. 8.6.22 Register L_DATA_MSB (address = 0x24) [reset = 0x00]
      23. 8.6.23 Register LHR_RCOUNT_LSB (address = 0x30) [reset = 0x00]
      24. 8.6.24 Register LHR_RCOUNT_MSB (address = 0x31) [reset = 0x00]
      25. 8.6.25 Register LHR_OFFSET_LSB (address = 0x32) [reset = 0x00]
      26. 8.6.26 Register LHR_OFFSET_MSB (address = 0x33) [reset = 0x00]
      27. 8.6.27 Register LHR_CONFIG (address = 0x34) [reset = 0x00]
      28. 8.6.28 Register LHR_DATA_LSB (address = 0x38) [reset = 0x00]
      29. 8.6.29 Register LHR_DATA_MID (address = 0x39) [reset = 0x00]
      30. 8.6.30 Register LHR_DATA_MSB (address = 0x3A) [reset = 0x00]
      31. 8.6.31 Register LHR_STATUS (address = 0x3B) [reset = 0x00]
      32. 8.6.32 Register RID (address = 0x3E) [reset = 0x02]
      33. 8.6.33 Register DEVICE_ID (address = 0x3F) [reset = 0xD4]
  9. 9 Application and Implementation
    1. 9.1 Application Information
      1. 9.1.1  TI Designs and Application Notes
      2. 9.1.2  Theory of Operation
      3. 9.1.3  RP+L Mode Calculations
      4. 9.1.4  LDC1101 RP Configuration
      5. 9.1.5  Setting Internal Time Constant 1
      6. 9.1.6  Setting Internal Time Constant 2
      7. 9.1.7  MIN_FREQ and Watchdog Configuration
      8. 9.1.8  RP+L Sample Rate Configuration With RESP_TIME
      9. 9.1.9  High Resolution Inductance Calculation (LHR mode)
      10. 9.1.10 LHR Sample Rate Configuration With RCOUNT
      11. 9.1.11 Setting RPMIN for LHR Measurements
      12. 9.1.12 Sensor Input Divider
      13. 9.1.13 Reference Clock Input
      14. 9.1.14 INTB Reporting on SDO
      15. 9.1.15 DRDY (Data Ready) Reporting on SDO
      16. 9.1.16 Comparator Functionality
    2. 9.2 Typical Application
      1. 9.2.1 Design Requirements
      2. 9.2.2 Detailed Design Procedure
        1. 9.2.2.1 Device Configuration for RP+L Measurement with an Example Sensor
        2. 9.2.2.2 Device Configuration for LHR Measurement with an Example Sensor
      3. 9.2.3 Application Curves
  10. 10Power Supply Recommendations
  11. 11Layout
    1. 11.1 Layout Guidelines
      1. 11.1.1 Ground and Power Planes
      2. 11.1.2 CLKIN Routing
      3. 11.1.3 Capacitor Placement
      4. 11.1.4 Sensor Connections
    2. 11.2 Layout Example
  12. 12Device and Documentation Support
    1. 12.1 Device Support
      1. 12.1.1 Development Support
    2. 12.2 Documentation Support
      1. 12.2.1 Related Documentation
    3. 12.3 Community Resources
    4. 12.4 Trademarks
    5. 12.5 Electrostatic Discharge Caution
    6. 12.6 Glossary
  13. 13Mechanical, Packaging, and Orderable Information

1 Features

  • Wide Operating Voltage Range: 1.8 V to 3.3 V
  • Sensor Frequency Range: 500 kHz to 10 MHz
  • RP Resolution: 16-Bit
  • L Resolution: 16- or 24-Bit
  • 180-kSPS Conversion Rate
  • Threshold Detection Functionality
  • 1% Part-to-Part Variation in RP Measurement
  • Supply Current:
    • 1.4-µA Shutdown mode
    • 135-µA Sleep mode
    • 1.9-mA Active Mode (no sensor connected)
  • Sub-Micron Distance Resolution Achievable
  • Remote Sensor Placement Isolating the LDC from Harsh Environments
  • Robust Against Environmental Interferences such as Oil, Water, Dirt, or Dust
  • Minimal External Components
  • Magnet-Free Operation
  • Operating Temperature: –40°C to +125°C

2 Applications

  • High-Speed Gear Counting
  • High-Speed Event Counting
  • Motor Speed Sensing
  • Knobs and Dials for Appliances, Automotive, and Consumer Applications
  • HMI for Appliances, Automotive, and Consumer Applications
  • Buttons and Keypads
  • Motor Control
  • Metal Detection

3 Description

The LDC1101 is a 1.8-V to 3.3-V, high-resolution inductance-to-digital converter for short-range, high-speed, contactless sensing of position, rotation, or motion, enabling reliable, accurate measurements even in the presence of dust or dirt, making it ideal for open or harsh environments.

The LDC1101 features dual inductive measurement cores, allowing for > 150 ksps 16-bit RP and L measurements simultaneous with a high-resolution L measurement which can sample at > 180 ksps with a resolution of up to 24 bits. The LDC1101 includes a threshold-compare function which can be dynamically updated while the device is running.

Inductive sensing technology enables precise measurement of linear/angular position, displacement, motion, compression, vibration, metal composition, and many other applications in markets including automotive, consumer, computer, industrial, medical, and communications. Inductive sensing offers better performance and reliability at lower cost than other, competing solutions.

The LDC1101 offers these benefits of inductive sensing in a small 3-mm × 3-mm 10-pin VSON package. The LDC1101 can be easily configured by a microcontroller using the 4-pin SPI™.

Device Information(1)

PART NUMBER PACKAGE BODY SIZE (NOM)
LDC1101 VSON (10) 3.00 mm × 3.00 mm
  1. For all available packages, see the orderable addendum at the end of the data sheet.

4 Simplified Schematic

LDC1101 simplified_schematic_snosd01.gif