MF

Magnetic Field Sensors User Guide

Overview


The Magnetic Field Sensors app allows you to model and simulate the function of Analog Devices' anisotropic magnetoresistive (AMR) technologies, such as:



Using the app, you will be able to simulate the component's function and collect critical data regarding its performance in settings relevant to your desired application, according to several variable parameters:


  • Sensor and magnet relative position
  • Magnet dimensions
  • Material
  • Temperature
  • Tolerances and geometry



Getting Started


  • Access the vLab page and navigate to Apps.
  • Select the Magnetic Field Sensors app.
  • Click Open App.
  • Choose one product from the dropdown menu: ADA4570, ADA4571, or ADA4571-2.

Once a new project is created, you can see the Product and Configuration fields to your left and the Diagram of the magnet and sensor on your right.


/assets/user-guides/mfs-overview.png

Figure 1. New project



Configure


1. Sensor Position


The Magnetic Field Sensors app can simulate use of the tool with either an end-of-shaft position or one in a linear travel setup (e.g., the magnet moving parallel to the sensor).


Different sensor positions will present different configuration options.


2. Configuration Parameters


The configuration parameters vary according to the sensor position.


2.1. For end-of-shaft positioned sensors input:


  • Magnet Dimension
  • Temperature
  • Magnet Material, along with the associated remanence in militesla (mT) and temperature coefficient in %/Kelvin format
  • Tolerances – the maximum of alignment error and run out for X and Y, both in millimeters (mm)

The following information should be taken into consideration in end-of-shaft configurations:


  • Geometry/Travel distances are not a concern in this situation, so these parameters can be ignored.
  • Specification of tolerances is important as it will provide information about how much offset or runout the system can withstand.
  • If the magnet shape has a diametric or split axial shape, you will need to enter diameter data as opposed to length and width; height is analyzed for all magnet shapes.

2.2. For linear travel sensor input:


  • Dimension, in millimeters (mm): height, length, width, and magnetic distance to sensor package edge
  • Geometry, in millimeters (mm): initial Z and X travel distances as well as travel in the -X direction
  • Temperature values for maximum and minimum, in Celsius (°C) or Fahrenheit (°F)

Because ADA4570 and ADA4571 can operate in environments with a maximum temperature of 150°C, do not set the high-temperature value greater than 150.


/assets/user-guides/mfs-configuration.png

Figure 2. Configuration



Run the Simulation


After inputting (and double-checking) the values in your configuration, click Run.


Within a few seconds, the Magnetic Field Sensors app will analyze the parameters you offered, and it will chart the results in the tabs above the main field of the app:


  • Magnetic Field
  • Output Voltage
  • Error



Analyze Results


Each result tab will present you with the following data:


  • Magnetic Field tab – displays the magnetic field seen at the senor, in the X and Y axes, as the magnet is rotated through a full mechanical revolution. The strength of the magnetic field is expressed in militesla (mT) and is shown high, low and room temperatures and angles from 0 to 360 degrees (°).

  • Voltage tab – shows waveforms displaying the voltage of the output signals at high, low and room temperatures as the magnet is rotated.

  • Error tab – displays the simulated accuracy of the sensor (magnet, sensor and ideal ADC) when amplitude and offset calibrations are completed.

Note: If simulating the ADA4571-2, the results will include data for both channels.


/assets/user-guides/mfs-analyze.png

Figure 3. Results



Additional Features


  • To see the exact magnetic field strength, voltage output, or system error as the magnet is rotated, hover over the desired spot on the chart with your mouse, and the data will appear in a small rectangular box.
  • You can customize the results shown on the graphs. If you wish to remove or re-add a result, click on the corresponding temperature button above the chart (Low Temperature, Room Temperature, High Temperature).
  • If you run different configurations, you can access and compare the results in the Run Results field by clicking Run 1, Run 2 and so on.
  • To look at graphs in more detail, you can toggle the Run Results field on or off, or click on the fullscreen icon to show the graphs on the entire screen.
  • You can download the data in each tab in various formats:
    • to export the simulated values as CSV, click the CSV icon above the chart.
    • to export a screenshot as PNG, click the picture icon above the chart.