SNOSCZ7A December   2015  – January 2016 LDC0851

PRODUCTION DATA.  

  1. Features
  2. Applications
  3. Description
  4. Simplified Schematic
  5. Revision History
  6. Pin Configuration and Functions
  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 Interface Voltage Levels
    7. 7.7 Timing Requirements
    8. 7.8 Typical Characteristics
  8. Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1 Basic Operation Mode
      2. 8.3.2 Threshold Adjust Mode
      3. 8.3.3 Setting the Threshold Adjust Values
      4. 8.3.4 Hysteresis
      5. 8.3.5 Conversion Time
      6. 8.3.6 Power-Up Conditions
    4. 8.4 Device Functional Modes
      1. 8.4.1 Shutdown Mode
      2. 8.4.2 Active Mode
  9. Application and Implementation
    1. 9.1 Application Information
      1. 9.1.1 Sensor Design
        1. 9.1.1.1 Sensor Frequency
        2. 9.1.1.2 Sensor Design Procedure
    2. 9.2 Typical Application
      1. 9.2.1 Event Counting
        1. 9.2.1.1 Design Requirements
        2. 9.2.1.2 Detailed Design Procedure
        3. 9.2.1.3 Application Curves
      2. 9.2.2 Coarse Position Sensing
        1. 9.2.2.1 Design Requirements
        2. 9.2.2.2 Detailed Design Procedure
        3. 9.2.2.3 Application Curves
      3. 9.2.3 Low Power Operation
        1. 9.2.3.1 Design Requirements
        2. 9.2.3.2 Detailed Design Procedure
        3. 9.2.3.3 Application Curves
  10. 10Power Supply Recommendations
  11. 11Layout
    1. 11.1 Layout Guidelines
    2. 11.2 Layout Example
      1. 11.2.1 Side by Side Coils
      2. 11.2.2 Stacked Coils
  12. 12Device and Documentation Support
    1. 12.1 Device Support
      1. 12.1.1 Development Support
    2. 12.2 Community Resources
    3. 12.3 Trademarks
    4. 12.4 Electrostatic Discharge Caution
    5. 12.5 Glossary
  13. 13Mechanical, Packaging, and Orderable Information

Package Options

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

11 Layout

11.1 Layout Guidelines

The LDC0851 requires minimal external components for effective operation. An LDC0851 design should follow good layout techniques - providing good grounding and clean supplies are critical for optimum operation. Due to the small physical size of the LDC0851, use of surface mount 0402 or smaller components can ease routing. It is important to keep the routing symmetrical and minimize parasitic capacitances for LSENSE and LREF. The sensor capacitor should be placed close to the IC and keep traces far apart to minimize the effects of parasitic capacitance. For optimum performance, it is recommended to use a C0G/NP0 for the sensor capacitor.

11.2 Layout Example

11.2.1 Side by Side Coils

The use of side by side coils is recommended for many applications that require a 2 layer PCB or that require very accurate temperature compensation. For side by side coils it is recommended to put them on the same PCB, even if using a remote sensing application. This will keep the tolerances and mismatch between the coils as small as possible. An example layout of side by side coils is shown in Figure 34.

LDC0851 layout_snoscz7.png Figure 34. Side by Side Coil Layout Example

11.2.2 Stacked Coils

Use of stacked coils may be desirable to conserve board space and to prevent false triggering when a target approaches from the bottom. A 4 layer PCB with a thick inner layer is recommended to achieve the best results. It is important to note the direction and polarity of the sense coil and reference coils with respect to each other. The recommended configuration is shown below.

LDC0851 stacked_coil_sensor_design_snoscz7.gif Figure 35. Stacked Coil Recommended Connections and Direction