• Menu
  • Product
  • Email
  • PDF
  • Order now

  • Contactless, Hall-Effect Variable-Speed Trigger Reference Design With External Field Protection

    • TIDUBY9 December   2021

       

  • CONTENTS
  • SEARCH
  • Contactless, Hall-Effect Variable-Speed Trigger Reference Design With External Field Protection
  1.   Description
  2.   Resources
  3.   Features
  4.   Applications
  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 Support Resources
    5. 4.5 Trademarks
  10. IMPORTANT NOTICE
search No matches found.
  • Full reading width
    • Full reading width
    • Comfortable reading width
    • Expanded reading width
  • Card for each section
  • Card with all content

 

DESIGN GUIDE

Contactless, Hall-Effect Variable-Speed Trigger Reference Design With External Field Protection

Description

This reference design uses Hall-effect sensors to implement a trigger that outputs a varying voltage based on how far the trigger is pressed. These types of triggers are well-suited for use in cordless power tools or any other end equipment that utilize trigger displacement information. The design uses a contactless approach that reduces wear and tear compared to traditional mechanical-based triggers, thereby increasing product lifetime. Low-power Hall-effect switches are used along with a load switch to keep the system in a low-power standby mode when the trigger is not pressed. In addition, an optional magnetic field protection feature is available that disables the voltage output when a strong, external magnetic field is present.

Resources

TIDA-060032 Design Folder
HALL-TRIGGER-EVM Tool Folder
DRV5056, DRV5032 Product Folder
TPS709, TPS22917 Product Folder
SN74HCS00, SN74AUP1G00 Product Folder
TLV9061 Product Folder
Ask our TI E2E™ support experts

Features

  • Up to 10 mm of trigger displacement translated to voltage
    • Measured voltage error without calibration
      < 3%
    • Measured voltage error with calibration < 0.5%
  • (Optional) Disables voltage output when strong external magnetic fields are detected
  • Operates from AAA batteries or 5 V to 30 V external power supply
  • Low system current consumption in sleep mode
    • Maximum protection against external magnetic fields selected: 6.9 µA
    • Minimum protection against external magnetic fields selected: 3.5 µA

Applications

  • Cordless power tool
  • Surgical equipment
  • Mixer, blender and food processor
  • Mains powered tools

 
Texas Instruments

© Copyright 1995-2025 Texas Instruments Incorporated. All rights reserved.
Submit documentation feedback | IMPORTANT NOTICE | Trademarks | Privacy policy | Cookie policy | Terms of use | Terms of sale