SLIA097 March   2022 DRV5011 , DRV5011 , DRV5012 , DRV5012 , DRV5013 , DRV5013 , DRV5015 , DRV5015 , DRV5021 , DRV5021 , DRV5023 , DRV5023 , DRV5032 , DRV5032 , DRV5033 , DRV5033 , TMAG5110 , TMAG5110 , TMAG5111 , TMAG5111 , TMAG5123 , TMAG5123 , TMAG5231 , TMAG5231 , TMAG5328 , TMAG5328

 

  1.   Trademarks
  2. 1Introduction
  3. 2Flow Meter Design
    1. 2.1 Mechanical Considerations
    2. 2.2 Magnetic Considerations
      1. 2.2.1 Material
      2. 2.2.2 Geometry
      3. 2.2.3 Magnetic Deign Tools
    3. 2.3 Hall-Effect Sensor Considerations
      1. 2.3.1 Device Sensitivity
      2. 2.3.2 Unipolar Switch
      3. 2.3.3 Omnipolar Switch
      4. 2.3.4 1D Latch
      5. 2.3.5 2D Integrated Latch
      6. 2.3.6 Bandwidth
      7. 2.3.7 Package
      8. 2.3.8 Power Consumption
  4. 3Flow Meter Development
    1. 3.1 3D-Print Recommendations
    2. 3.2 Flow Meter Assembly Considerations
    3. 3.3 Flow Meter Assembly Guide
      1. 3.3.1 Shaft Installation
      2. 3.3.2 Bearing Installation
      3. 3.3.3 Magnet Installation
      4. 3.3.4 Impeller Installation
      5. 3.3.5 O-ring Installation
      6. 3.3.6 Flow Meter Top Installation
      7. 3.3.7 PCB Mounting
      8. 3.3.8 Cover Installation
  5. 4Flow Meter Evaluation
    1. 4.1 Flow Meter Testing
  6. 5Error Sources
    1. 5.1 Mechanical Error
    2. 5.2 Sampling Error
    3. 5.3 Magnetic Error
  7. 6Flow Meter PCB
    1. 6.1 PCB Schematic
    2. 6.2 PCB Layout
  8. 7Bill of Materials (BOM)
  9. 8References

2.3.4 1D Latch

1D Hall-effect latches share similar operational characteristics as switches, but uniquely retain the previous output state until a magnetic pole of the opposite polarity is detected. Therefore, it is necessary that the sensor detect changing magnetic polarities to create corresponding changes on the output. Assuming equal spacing of magnets, the output waveform of a latch is approximately 50% duty cycle regardless of sensing frequency. Figure 2-5 demonstrates the operational characteristics of a Hall-effect latch.

Figure 2-5 Latch Operation