JAJU835 December   2021

 

  1.   概要
  2.   リソース
  3.   特長
  4.   アプリケーション
  5.   5
  6. 1System Description
    1. 1.1 Key System Specifications
  7. 2System Overview
    1. 2.1 Block Diagram
      1.      10
    2. 2.2 Highlighted Products
      1. 2.2.1 DRV5056
      2. 2.2.2 DRV5032
      3. 2.2.3 TPS709
      4. 2.2.4 SN74HCS00
      5. 2.2.5 TPS22917
      6. 2.2.6 SN74AUP1G00
      7. 2.2.7 TLV9061
    3. 2.3 Design Considerations
      1. 2.3.1 Design Hardware Implementation
        1. 2.3.1.1 Hall-Effect Switches
          1. 2.3.1.1.1 U1 Wake-Up Sensor Configuration
          2. 2.3.1.1.2 U2 Stray-Field Sensor Configuration
          3. 2.3.1.1.3 U3 and U4 Tamper Sensor Configuration
          4. 2.3.1.1.4 Hall Switch Placement
            1. 2.3.1.1.4.1 Placement of U1 and U2 Sensors
              1. 2.3.1.1.4.1.1 U1 and U2 Magnetic Flux Density Estimation Results
            2. 2.3.1.1.4.2 Placement of U3 and U4 Hall Switches
              1. 2.3.1.1.4.2.1 U3 and U4 Magnetic Flux Density Estimation Results
          5. 2.3.1.1.5 Using Logic Gates to Combine Outputs from Hall-Effect Switches
        2. 2.3.1.2 Linear Hall-Effect Sensor Output
          1. 2.3.1.2.1 DRV5056 Power
          2. 2.3.1.2.2 DRV5056 Output Voltage
          3. 2.3.1.2.3 DRV5056 Placement
        3. 2.3.1.3 Power Supply
        4. 2.3.1.4 Transistor Circuit for Creating High-Voltage Enable Signal
      2. 2.3.2 Alternative Implementations
        1. 2.3.2.1 Replacing 20-Hz Tamper Switches With 5-Hz Tamper Switches
        2. 2.3.2.2 Using Shielding to Replace Tamper Switches and Stray Field Switch
        3. 2.3.2.3 Replacing Hall-Based Wake-Up Alert Function With a Mechanical Switch
  8. 3Hardware, Software, Testing Requirements, and Test Results
    1. 3.1 Hardware Requirements
      1. 3.1.1 Installation and Demonstration Instructions
      2. 3.1.2 Test Points and LEDs
      3. 3.1.3 Configuration Options
        1. 3.1.3.1 Disabling Hall-Effect Switches
        2. 3.1.3.2 Configuring Hardware for Standalone Mode or Connection to External Systems
    2. 3.2 Test Setup
      1. 3.2.1 Output Voltage Accuracy Testing
      2. 3.2.2 Magnetic Tampering Testing
      3. 3.2.3 Current Consumption Testing
    3. 3.3 Test Results
      1. 3.3.1 Output Voltage Accuracy Pre-Calibration Results
      2. 3.3.2 Output Voltage Accuracy Post-Calibration Results
      3. 3.3.3 Magnetic Tampering Results
      4. 3.3.4 Current Consumption Results
  9. 4Design and Documentation Support
    1. 4.1 Design Files
      1. 4.1.1 Schematics
      2. 4.1.2 BOM
    2. 4.2 Tools and Software
    3. 4.3 Documentation Support
    4. 4.4 サポート・リソース
    5. 4.5 Trademarks
Hall Switch Placement

The magnetic flux density detected by a Hall sensor is dependent on the magnet dimensions, magnet material, and the distance from the magnet to the sensing element within the Hall sensor. Note that the location of the sensing element varies for each package of the DRV5032. Figure 2-13 shows the location of the sensing element in the X2SON and SOT-23 packages of the DRV5032. The two pictures on the right express the sensing location with respect to the bottom of the X2SON and SOT-23 packages of the DRV5032. To express the sensing location so that it is with respect to the top of a package, subtract the readings that are with respect to the bottom of the package from the package height. As an example, if the X2SON package height is 400 μm and the distance from the bottom of the package to the sensing element is 250 μm, the distance from the top of the X2SON package to the sensing element is 400 – 250 = 150 μm. Similarly, if the SOT-23 height is 1120 μm and the distance from the bottom of the package to the sensing element is 650 μm, the distance from the top of the SOT-23 package to the sensing element is 1120 – 650 = 470 μm.

GUID-20211209-SS0I-RXS7-G2PK-VPVTKXK3FKRC-low.pngFigure 2-13 Location of Sensing Element Within X2SON and SOT-23 Packages of DRV5032

Based on the magnet specifications and the distance from the magnet to the sensing elements, simulations were done to estimate the expected sensed magnetic flux density at each sensor across the trigger displacement range. For detailing the distances from the magnet to the Hall sensors, the convention shown in Figure 2-14 was used. In this figure, the z-axis is defined as going from right to left (this is the direction of the trigger movement), the y-axis is defined as going from up to down, and the x direction is defined as going into the page (from the top layer of the PCB to the bottom layer of the PCB).

GUID-20211209-SS0I-2K5P-7SN9-GTDJWT4CBSQB-low.pngFigure 2-14 Board Picture Within 3D Printed Trigger Module