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

12.1 Layout Guidelines

The TMCS1108-Q1 is specified for a continuous current handling capability on the TMCS1108EVM, which uses 3-oz copper pour planes. This current capability is fundamentally limited by the maximum device junction temperature and the thermal environment, primarily the PCB layout and design. To maximize current-handling capability and thermal stability of the device, take care with PCB layout and construction to optimize the thermal capability. Efforts to improve the thermal performance beyond the design and construction of the TMCS1108EVM can result in increased continuous-current capability due to higher heat transfer to the ambient environment. Keys to improving thermal performance of the PCB include:

  • Use large copper planes for both input current path and isolated power planes and signals.
  • Use heavier copper PCB construction.
  • Place thermal via farms around the isolated current input.
  • Provide airflow across the surface of the PCB.

The TMCS1108-Q1 senses external magnetic fields, so make sure to minimize adjacent high-current traces in close proximity to the device. The input current trace can contribute additional magnetic field to the sensor if the input current traces are routed parallel to the vertical axis of the package. Figure 12-1 illustrates the most optimal input current routing into the TMCS1108-Q1. As the angle that the current approaches the device deviates from 0° to the horizontal axis, the current trace contributes some additional magnetic field to the sensor, increasing the effective sensitivity of the device. If current must be routed parallel to the package vertical axis, move the routing away from the package to minimize the impact to the sensitivity of the device. Terminate the input current path directly underneath the package lead footprint, and use a merged copper input trace for both the IN+ and IN– inputs.

GUID-F8EA8169-F58F-4C5C-B172-01770D46E04E-low.gifFigure 12-1 Magnetic Field Generated by Input Current Trace

In addition to thermal and magnetic optimization, make sure to consider the PCB design required creepage and clearance for system-level isolation requirements. Maintain required creepage between solder stencils, as shown in Figure 12-2, if possible. If not possible to maintain required PCB creepage between the two isolated sides at board level, add additional slots or grooves to the board. If more creepage and clearance is required for system isolation levels than is provided by the package, the entire device and solder mask can be encapsulated with an overmold compound to meet system-level requirements.

GUID-D6C151B2-555F-47F7-981E-23F9B61ABB2D-low.gifFigure 12-2 Layout for System Creepage Requirements