SLYS044B December   2021  – May 2024 TMAG5328

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Pin Configuration and Functions
  6. 5 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. 6 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 Magnetic Response
      3. 6.3.3 Output Type
      4. 6.3.4 Sampling Rate
      5. 6.3.5 Adjustable Threshold
        1. 6.3.5.1 Adjustable Resistor
        2. 6.3.5.2 Adjustable Voltage
      6. 6.3.6 Hall Element Location
    4. 6.4 Device Functional Modes
  8. 7 Application and Implementation
    1. 7.1 Application Information
      1. 7.1.1 Valid TMAG5328 Configurations
    2. 7.2 Typical Applications
      1. 7.2.1 Refrigerator Door Open/Close Detection
        1. 7.2.1.1 Design Requirements
        2. 7.2.1.2 Detailed Design Procedure
    3. 7.3 Power Supply Recommendations
    4. 7.4 Layout
      1. 7.4.1 Layout Guidelines
      2. 7.4.2 Layout Example
  9. 8 Device and Documentation Support
    1. 8.1 Device Nomenclature
    2. 8.2 Receiving Notification of Documentation Updates
    3. 8.3 Support Resources
    4. 8.4 Trademarks
    5. 8.5 Electrostatic Discharge Caution
    6. 8.6 Glossary
  10. 9 Revision History
  11. 10Mechanical, Packaging, and Orderable Information

7.1.1 Valid TMAG5328 Configurations

The TMAG5328 BOP is set by connecting a resistor or a voltage source to the “ADJ” pin. Figure 7-1 shows how to use resistor R1 to set the BOP. Figure 7-2 shows hows to use a DAC as a voltage source for setting the BOP. Using the DAC allows the user to dynamically change the BOP with software. To use a DAC, the output of the DAC must settle within 4µs after the 80µA current source of the “ADJ” pin is turned ON.

TMAG5328 Setting BOP of One TMAG5328 Device Using a Resistor Figure 7-1 Setting BOP of One TMAG5328 Device Using a Resistor
TMAG5328 Setting BOP of One TMAG5328 Device Using a DAC Figure 7-2 Setting BOP of One TMAG5328 Device Using a DAC

As a DAC alternative, Figure 7-3 shows how a voltage divider can be used as a voltage source. In Figure 7-3, an operational amplifier is placed between the voltage divider and the “ADJ” pin so that the voltage fed to the “ADJ” pin is not impacted by the internal current source of the TMAG5328 when the current source is turned ON. To use an op amp, the output of the op amp must settle within 4µs after the 80µA current source of the “ADJ” pin is turned ON.

TMAG5328 Setting BOP of One TMAG5328 Device Using a Voltage Divider Figure 7-3 Setting BOP of One TMAG5328 Device Using a Voltage Divider

A potentiometer or rheostat can be integrated into a voltage divider, and the user can adjust this potentiometer to dynamically update the BOP. Figure 7-4 shows how to use a potentiometer in a voltage divider to set the BOP of the TMAG5328. The maximum output voltage, which determines the maximum BOP, is set based on the values of resistors R1 and R3. The minimum output voltage, which determines the minimum BOP, is set based on the values of the maximum potentiometer resistance, R1 resistance, and R3 resistance. Select a minimum output voltage greater than 0.16V and a maximum output voltage less than 1.2V.

TMAG5328 Setting BOP of One TMAG5328 Device Using a Voltage Divider and Potentiometer Figure 7-4 Setting BOP of One TMAG5328 Device Using a Voltage Divider and Potentiometer

Figure 7-5 shows how the TMAG5328’s internal current source can drive a potentiometer or rheostat instead of a voltage divider. In this implementation, make sure the resistor R2 is at least 2kΩ to ensure that the “ADJ” resistance is always above the minimum 2kΩ. The sum of the maximum potentiometer resistance and the resistance of R1 must also be less than 15kΩ.

TMAG5328 Setting BOP of One TMAG5328 Device Using a Potentiometer and the TMAG5328’s Internal Current Source Figure 7-5 Setting BOP of One TMAG5328 Device Using a Potentiometer and the TMAG5328’s Internal Current Source

Multiple TMAG5328 devices can be used in the same system. When setting the BOP using a resistor, TI recommends that each TMAG5328 has a “ADJ” resistor, even if multiple TMAG5328 devices have the same “ADJ” resistor value. Figure 7-6 shows an example implementation that has three TMAG5328 devices. If each device is set to the same BOP, then the resistances of R1, R2, and R3 are equal.

TMAG5328 Setting BOP of Three TMAG5328 Devices Using Three Resistors Figure 7-6 Setting BOP of Three TMAG5328 Devices Using Three Resistors

When setting the BOP using a DAC, one DAC can be used to set the “ADJ” pin voltage of multiple devices only if the output of the DAC can sink the current from all of the TMAG5328 devices. Figure 7-7 shows an example of a DAC driving the “ADJ” pin of three TMAG5328 devices. A DAC can only work reliably in this specific scenario if the output of the DAC can settle within 4µs after being exposed to the three “ADJ” current sources. Each current source is 80µA, therefore the DAC can only reliably work if the output of the DAC can settle within 4µs after being exposed to 80 x 3 = 240µA of current.

TMAG5328 Setting BOP of Three TMAG5328 Devices Using a DAC Figure 7-7 Setting BOP of Three TMAG5328 Devices Using a DAC