SBOSA72 July   2021 TMCS1108-Q1

PRODUCTION DATA  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Revision History
  5. 5 Device Comparison
  6. 6 Pin Configuration and Functions
  7. 7 Specifications
    1. 7.1 Absolute Maximum Ratings
    2. 7.2 ESD Ratings
    3. 7.3 Recommended Operating Conditions
    4. 7.4 Thermal Information
    5. 7.5 Power Ratings
    6. 7.6 Electrical Characteristics
    7. 7.7 Typical Characteristics
      1. 7.7.1 Insulation Characteristics Curves
  8. 8 Parameter Measurement Information
    1. 8.1 Accuracy Parameters
      1. 8.1.1 Sensitivity Error
      2. 8.1.2 Offset Error and Offset Error Drift
      3. 8.1.3 Nonlinearity Error
      4. 8.1.4 Power Supply Rejection Ratio
      5. 8.1.5 Common-Mode Rejection Ratio
      6. 8.1.6 External Magnetic Field Errors
    2. 8.2 Transient Response Parameters
      1. 8.2.1 Slew Rate
      2. 8.2.2 Propagation Delay and Response Time
      3. 8.2.3 Current Overload Parameters
      4. 8.2.4 CMTI, Common-Mode Transient Immunity
    3. 8.3 Safe Operating Area
      1. 8.3.1 Continuous DC or Sinusoidal AC Current
      2. 8.3.2 Repetitive Pulsed Current SOA
      3. 8.3.3 Single Event Current Capability
  9. 9 Detailed Description
    1. 9.1 Overview
    2. 9.2 Functional Block Diagram
    3. 9.3 Feature Description
      1. 9.3.1 Current Input
      2. 9.3.2 High-Precision Signal Chain
        1. 9.3.2.1 Lifetime and Environmental Stability
        2. 9.3.2.2 Frequency Response
        3. 9.3.2.3 Transient Response
      3. 9.3.3 Internal Reference Voltage
      4. 9.3.4 Current-Sensing Measurable Ranges
    4. 9.4 Device Functional Modes
      1. 9.4.1 Power-Down Behavior
  10. 10Application and Implementation
    1. 10.1 Application Information
      1. 10.1.1 Total Error Calculation Examples
        1. 10.1.1.1 Room Temperature Error Calculations
        2. 10.1.1.2 Full Temperature Range Error Calculations
    2. 10.2 Typical Application
      1. 10.2.1 Design Requirements
      2. 10.2.2 Detailed Design Procedure
      3. 10.2.3 Application Curve
  11. 11Power Supply Recommendations
  12. 12Layout
    1. 12.1 Layout Guidelines
    2. 12.2 Layout Example
  13. 13Device and Documentation Support
    1. 13.1 Device Support
      1. 13.1.1 Development Support
    2. 13.2 Documentation Support
      1. 13.2.1 Related Documentation
    3. 13.3 Receiving Notification of Documentation Updates
    4. 13.4 Support Resources
    5. 13.5 Trademarks
    6. 13.6 Electrostatic Discharge Caution
    7. 13.7 Glossary
  14. 14Mechanical, Packaging, and Orderable Information

Package Options

Refer to the PDF data sheet for device specific package drawings

Mechanical Data (Package|Pins)
  • D|8
Thermal pad, mechanical data (Package|Pins)
Orderable Information

8.1.6 External Magnetic Field Errors

The TMCS1108-Q1 does not have stray field-rejection capabilities, so external magnetic fields from adjacent high-current traces or nearby magnets can impact the output measurement. The total sensitivity (S) of the device is comprised of the initial transformation of input current to magnetic field quantified as the magnetic coupling factor (G), as well as the sensitivity of the Hall element and the analog circuitry that is factory calibrated to provide a final sensitivity. The output voltage is proportional to the input current by the device sensitivity, as defined in Equation 11.

Equation 11. GUID-444CB38A-9B00-4E5D-A111-CB20AF55BED7-low.gif

where

  • S is the TMCS1108-Q1 sensitivity in mV/A.
  • G is the magnetic coupling factor in mT/A.
  • SHall is the sensitivity of the Hall plate in mV/mT.
  • AV is the calibrated analog circuitry gain in V/V.

An external field, BEXT, is measured by the Hall sensor and signal chain, in addition to the field generated by the leadframe current, and is added as an extra input term in the total output voltage function:

Equation 12. GUID-374A1D22-EDDF-4ABA-B797-80A5F17CA6E4-low.gif

Observable from Equation 12 is that the impact of an external field is an additional equivalent input current signal, IBEXT, shown in Equation 13. This effective additional input current has no dependence on Hall or analog circuitry sensitivity, so all gain variants have equivalent input-referred current error due to external magnetic fields.

Equation 13. GUID-AA59B9B7-A9A8-438A-B8A2-DBECEE43B74D-low.gif

This additional current error generates a percentage error defined by Equation 14.

Equation 14. GUID-1EEBC7AA-A5E9-42A7-B96D-DEFFAE894101-low.gif