SLYS048B March   2023  – August 2024 TMAG6181-Q1

PRODUCTION DATA  

  1.   1
  2. Features
  3. Applications
  4. Description
  5. Pin Configuration and Functions
  6. Specifications
    1. 5.1 Absolute Maximum Ratings
    2. 5.2 ESD Ratings
    3. 5.3 Recommended Operating Conditions
    4. 5.4 Thermal Information
    5. 5.5 Electrical Characteristics
    6. 5.6 Magnetic Characteristics
    7. 5.7 Typical Characteristics
  7. Detailed Description
    1. 6.1 Overview
    2. 6.2 Functional Block Diagram
    3. 6.3 Feature Description
      1. 6.3.1 Magnetic Flux Direction
      2. 6.3.2 Sensors Location and Placement Tolerances
      3. 6.3.3 Magnetic Response
      4. 6.3.4 Parameters Definition
        1. 6.3.4.1 AMR Output Parameters
        2. 6.3.4.2 Transient Parameters
          1. 6.3.4.2.1 Power-On Time
        3. 6.3.4.3 Hall Sensor Parameters
        4. 6.3.4.4 Angle Accuracy Parameters
      5. 6.3.5 Automatic Gain Control (AGC)
      6. 6.3.6 Turns Counter
        1. 6.3.6.1 Rotation Tracking
      7. 6.3.7 Safety and Diagnostics
        1. 6.3.7.1 Device Level Checks
        2. 6.3.7.2 System Level Checks
    4. 6.4 Device Functional Modes
      1. 6.4.1 Operating Modes
        1. 6.4.1.1 Active Mode
        2. 6.4.1.2 Active-Turns Mode
        3. 6.4.1.3 Low-Power Mode
        4. 6.4.1.4 Sleep Mode
        5. 6.4.1.5 Fault Mode
  8. Application and Implementation
    1. 7.1 Application Information
      1. 7.1.1 Power Supply as the Reference for External ADC
      2. 7.1.2 AMR Output Dependence on Airgap Distance
      3. 7.1.3 Calibration of Sensor Errors
    2. 7.2 Typical Application
      1. 7.2.1 Design Requirements
      2. 7.2.2 Detailed Design Procedure
        1. 7.2.2.1 Designing with Multiple Sensors
          1. 7.2.2.1.1 Designing for Redundancy
          2. 7.2.2.1.2 Multiplexing Multiple Sensors
      3. 7.2.3 Application Curve
    3. 7.3 Power Supply Recommendations
    4. 7.4 Layout
      1. 7.4.1 Layout Guidelines
      2. 7.4.2 Layout Example
  9. Device and Documentation Support
    1. 8.1 Receiving Notification of Documentation Updates
    2. 8.2 Support Resources
    3. 8.3 Trademarks
    4. 8.4 Electrostatic Discharge Caution
    5. 8.5 Glossary
  10. Revision History
  11. 10Mechanical, Packaging, and Orderable Information

Package Options

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

Some applications require multiple angle position sensors to detect position in different parts of the system. In those cases, the primary challenge would be the availability of multiple ADC that are required to digitize the information from the sensors. In cases where the sensor is placed remotely away from the microcontroller, there can be multiple output lines between the sensor and microcontroller.

With the ability to place the output in high-impedance state during shutdown mode, multiple TMAG6181-Q1 devices can share the analog output. This can minimize the system cost by using a single ADC per channel. Figure 7-6 shows two devices that share the same analog output, with their respective SLEEP pins controlled by the microcontroller. A pulldown resistor can be used to pull the output to ground when both the devices are placed in shutdown mode.

TMAG6181-Q1 Multiple Sensors with Shared
                    Output Figure 7-6 Multiple Sensors with Shared Output

Figure 7-7 shows how the GPIOs of the microcontroller can be used to multiplex the outputs from the two sensors. When the GPIO1 goes high, Device 1 is enabled and drives the output line to the corresponding output after the power-on time. During this time, GPIO2 is driven low and Device 2 is placed in shutdown mode. When the output from the second device must be measured, the first device must be turned off before the second device is enabled, indicated by tmux in the timing diagram. B1 and B2 correspond to the magnetic fields seen by Device 1 and Device 2 respectively.

With the ability to support up to 10nF capacitive loads, the TMAG6181-Q1 can connect multiple sensors to the same output.

TMAG6181-Q1 Timing Diagram for
                    Multiplexing the Sensor Outputs Figure 7-7 Timing Diagram for Multiplexing the Sensor Outputs