SBOS743B July   2015  – September 2024 INA226-Q1

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 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 Basic ADC Functions
        1. 6.3.1.1 Power Calculation
        2. 6.3.1.2 Alert Pin
    4. 6.4 Device Functional Modes
      1. 6.4.1 Averaging and Conversion Time Considerations
      2. 6.4.2 Filtering and Input Considerations
    5. 6.5 Programming
      1. 6.5.1 Programming the Calibration Register
      2. 6.5.2 Programming the Power Measurement Engine
        1. 6.5.2.1 Calibration Register and Scaling
      3. 6.5.3 Simple Current Shunt Monitor Usage (No Programming Necessary)
      4. 6.5.4 Default Settings
      5. 6.5.5 Bus Overview
        1. 6.5.5.1 Serial Bus Address
        2. 6.5.5.2 Serial Interface
        3. 6.5.5.3 Writing to and Reading From the INA226-Q1
          1. 6.5.5.3.1 High-Speed I2C Mode
        4. 6.5.5.4 SMBus Alert Response
  8. 7 Registers
    1. 7.1 Register Maps
      1. 7.1.1  Configuration Register (00h) (Read/Write)
      2. 7.1.2  Shunt Voltage Register (01h) (Read-Only)
      3. 7.1.3  Bus Voltage Register (02h) (Read-Only) #GUID-792F23A7-1E45-4FB9-9334-0BF769622DE4/SBOS5477597
      4. 7.1.4  Power Register (03h) (Read-Only)
      5. 7.1.5  Current Register (04h) (Read-Only)
      6. 7.1.6  Calibration Register (05h) (Read/Write)
      7. 7.1.7  Mask/Enable Register (06h) (Read/Write)
      8. 7.1.8  Alert Limit Register (07h) (Read/Write)
      9. 7.1.9  Manufacturer ID Register (FEh) (Read-Only)
      10. 7.1.10 Die ID Register (FFh) (Read-Only)
  9. 8 Application and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Applications
      1. 8.2.1 High-Side Sensing Circuit Application
        1. 8.2.1.1 Design Requirements
        2. 8.2.1.2 Detailed Design Procedure
        3. 8.2.1.3 Application Curves
    3. 8.3 Power Supply Recommendations
    4. 8.4 Layout
      1. 8.4.1 Layout Guidelines
      2. 8.4.2 Layout Example
  10. 9 Device and Documentation Support
    1. 9.1 Device Support
      1. 9.1.1 Development Support
    2. 9.2 Receiving Notification of Documentation Updates
    3. 9.3 Support Resources
    4. 9.4 Trademarks
    5. 9.5 Electrostatic Discharge Caution
    6. 9.6 Glossary
  11. 10Revision History
  12. 11Mechanical, Packaging, and Orderable Information

6.5.2.1 Calibration Register and Scaling

The Calibration Register enables the user to scale the Current Register (04h) and Power Register (03h) to the most useful value for a given application. For example, set the Calibration Register such that the largest possible number is generated in the Current Register (04h) or Power Register (03h) at the expected full-scale point. This approach yields the highest resolution using the previously calculated minimum Current_LSB in the equation for the Calibration Register. The Calibration Register can also be selected to provide values in the Current Register (04h) and Power Register (03h) that either provide direct decimal equivalents of the values being measured, or yield a round LSB value for each corresponding register. After these choices are made, the Calibration Register also offers possibilities for end user system-level calibration. After determining the exact current by using an external ammeter, the value of the Calibration Register can then be adjusted based on the measured current result of the INA226-Q1 to cancel the total system error as shown in Equation 5.

Equation 5. C o r r e c t e d _ F u l l _ S c a l e _ C a l = t r u n c C a l × M e a s S h u n t C u r r e n t D e v i c e _ C u r r e n t