TIDUC07 March   2022

 

  1.   Description
  2.   Resources
  3.   Features
  4.   Applications
  5.   5
  6. 1System Description
  7. 2System Overview
    1. 2.1 Block Diagram
    2. 2.2 Highlighted Products
      1. 2.2.1 TMAG5170
      2. 2.2.2 DRV5055A4
    3. 2.3 Design Considerations
      1. 2.3.1 Magnet Selection
      2. 2.3.2 Magnet Shape
      3. 2.3.3 Magnet Rotation Speed
      4. 2.3.4 Sensor Location
      5. 2.3.5 Expected Performance
      6. 2.3.6 Layout for Sensor Location
      7. 2.3.7 45° Alignment
  8. 3Hardware, Software, Testing Requirements, and Test Results
    1. 3.1 Hardware Requirements
    2. 3.2 Test Setup
      1. 3.2.1 Test Equipment
      2. 3.2.2 Test Hardware Configuration
      3. 3.2.3 Test Software Configuration and Initial Data Capture
    3. 3.3 Test Results
      1. 3.3.1 Calibration Methods
      2. 3.3.2 TMAG5170 On-Axis
      3. 3.3.3 TMAG5170 In-Plane
      4. 3.3.4 TMAG5170 Off-Axis
      5. 3.3.5 TMAG5170 45° Alignment
      6. 3.3.6 DRV5055 Off Axis Result
  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

2.3.6 Layout for Sensor Location

One important factor when designing an angle encoder using these devices is the actual sensor location on the PCB. The sensor placement in the package may result with unintentional placement errors in any of the 3 axes.

GUID-20220208-SS0I-NWNW-7LDR-DHTR0DHHQSFS-low.png Figure 2-20 TIDA-060040 Sensor Placement
GUID-20220208-SS0I-WVQZ-HNB3-XZN64CP0VJWF-low.png Figure 2-21 DRV5055 Sensor Location

DRV5055 has the benefit that the sensor location in the XY plane is centered relative to the package. However, the implementation for this device requires two sensors placed 90° separated about the magnet. Additionally, it may be necessary to use an LPG through-hole package depending on the sensor location.

GUID-20220208-SS0I-X95Q-5LXN-2RQCSPMK2NBL-low.png Figure 2-22 TMAG5170 Sensor Location

For TMAG5170, the layout files TIDA-060040 contain an alignment layer which indicates the actual sensor location. Additionally, a via has been placed at the target sensor location to assist with alignment.