SNVSBF7 November   2019 LDC1001

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
    1.     Axial Distance Sensing Application
  4. 4 Revision History
  5. 5 Pin Configuration and Functions
    1.     Pin Functions
  6. 6 Specifications
    1. 6.1 Absolute Maximum Ratings
    2. 6.2 ESD Ratings
    3. 6.3 Recommended Operating Condition
    4. 6.4 Thermal Information
    5. 6.5 Electrical Characteristics
    6. 6.6 Timing Requirements
    7. 6.7 Typical Characteristics
  7. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1 Inductive Sensing
      2. 7.3.2 Measuring RP With LDC1001
      3. 7.3.3 Measuring Inductance With LDC1001
    4. 7.4 Device Functional Modes
      1. 7.4.1 Power Modes
      2. 7.4.2 INTB Pin Modes
        1. 7.4.2.1 Comparator Mode
        2. 7.4.2.2 Wake-Up Mode
        3. 7.4.2.3 DRDY Mode
    5. 7.5 Programming
      1. 7.5.1 SPI Description
        1. 7.5.1.1 Extended SPI Transactions
    6. 7.6 Register Maps
      1. 7.6.1 Register Description
        1. 7.6.1.1  Revision ID (Address = 0x00)
        2. 7.6.1.2  RP_MAX (Address = 0x01)
        3. 7.6.1.3  RP_MIN (Address = 0x02)
        4. 7.6.1.4  Watchdog Timer Frequency (Address = 0x03)
        5. 7.6.1.5  LDC Configuration (Address = 0x04)
        6. 7.6.1.6  Clock Configuration (Address = 0x05)
        7. 7.6.1.7  Comparator Threshold High LSB (Address = 0x06)
        8. 7.6.1.8  Comparator Threshold High MSB (Address = 0x07)
        9. 7.6.1.9  Comparator Threshold Low LSB (Address = 0x08)
        10. 7.6.1.10 Comparator Threshold Low MSB (Address = 0x09)
        11. 7.6.1.11 INTB Pin Configuration (Address = 0x0A)
        12. 7.6.1.12 Power Configuration (Address = 0x0B)
        13. 7.6.1.13 Status (Address = 0x20)
        14. 7.6.1.14 Proximity Data LSB (Address = 0x21)
        15. 7.6.1.15 Proximity Data MSB (Address = 0x22)
        16. 7.6.1.16 Frequency Counter LSB (Address = 0x23)
        17. 7.6.1.17 Frequency Counter Mid-Byte (Address = 0x24)
        18. 7.6.1.18 Frequency Counter MSB (Address = 0x25)
  8. 8 Application and Implementation
    1. 8.1 Application Information
      1. 8.1.1 Calculation of RP_MIN and RP_MAX
        1. 8.1.1.1 RP_MAX
        2. 8.1.1.2 RP_MIN
      2. 8.1.2 Output Data Rate
      3. 8.1.3 Choosing Filter Capacitor (CFA and CFB Pins)
    2. 8.2 Typical Application
      1. 8.2.1 Axial Distance Sensing Using a PCB Sensor With LDC1001
        1. 8.2.1.1 Design Requirements
        2. 8.2.1.2 Detailed Design Procedure
          1. 8.2.1.2.1 Sensor and Target
          2. 8.2.1.2.2 Calculating Sensor Capacitor
          3. 8.2.1.2.3 Choosing Filter Capacitor
          4. 8.2.1.2.4 Setting RP_MIN and RP_MAX
          5. 8.2.1.2.5 Calculating Minimum Sensor Frequency
        3. 8.2.1.3 Application Curve
  9. 9 Power Supply Recommendations
  10. 10Layout
    1. 10.1 Layout Guidelines
    2. 10.2 Layout Example
  11. 11Device and Documentation Support
    1. 11.1 Documentation Support
      1. 11.1.1 Related Documentation
    2. 11.2 Support Resources
    3. 11.3 Trademarks
    4. 11.4 Electrostatic Discharge Caution
    5. 11.5 Glossary
  12. 12Mechanical, Packaging, and Orderable Information

Package Options

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

7.6.1.4 Watchdog Timer Frequency (Address = 0x03)

Table 7. Watchdog Timer Frequency

BIT FIELD TYPE DEFAULT DESCRIPTION
7:0 Min Sensor Frequency R/W 0x45 Sets the watchdog timer. The Watchdog timer should be set based on the lowest sensor frequency. If this field is set to too high a value, then the LDC1001 may incorrectly determine a sensor oscillation timeout.
Equation 5. LDC1001 eq05_snoscx2.gif

where

  • ƒSENSOR is the sensor frequency
  • M is the register value to program for Min Sensor Frequency.
Example:
With a Sensor frequency is 1 MHz
Min Sensor Frequency = 68.94 × log10(1 × 106/2500) = Round to nearest integer (179.38) = 179