SBOS644D February   2013  – July 2022 INA231

PRODUCTION DATA  

  1. Features
  2. Applications
  3. Description
  4. Revision History
  5. Device Comparison
  6. Pin Configuration and Functions
  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 Electrical Characteristics
    6. 7.6 Timing Requirements: I2C Bus
    7. 7.7 Typical Characteristics
  8. Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1 Basic Analog-to-Digital Converter (ADC) Functions
        1. 8.3.1.1 Power Calculation
        2. 8.3.1.2 ALERT Pin
    4. 8.4 Device Functional Modes
      1. 8.4.1 Averaging and Conversion Time Considerations
    5. 8.5 Programming
      1. 8.5.1 Configure, Measure, and Calculate Example
      2. 8.5.2 Programming the Power Measurement Engine
        1. 8.5.2.1 Calibration Register and Scaling
      3. 8.5.3 Simple Current Shunt Monitor Usage (No Programming Necessary)
      4. 8.5.4 Default INA231 Settings
      5. 8.5.5 Writing to and Reading from the INA231
        1. 8.5.5.1 Bus Overview
          1. 8.5.5.1.1 Serial Bus Address
          2. 8.5.5.1.2 Serial Interface
        2. 8.5.5.2 High-Speed I2C Mode
      6. 8.5.6 SMBus Alert Response
    6. 8.6 Register Maps
      1. 8.6.1 Configuration Register (00h, Read/Write)
        1. 8.6.1.1 AVG Bit Settings [11:9]
        2. 8.6.1.2 VBUS CT Bit Settings [8:6]
        3. 8.6.1.3 VSH CT Bit Settings [5:3]
        4. 8.6.1.4 Mode Settings [2:0]
      2. 8.6.2 Shunt Voltage Register (01h, Read-Only)
      3. 8.6.3 Bus Voltage Register (02h, Read-Only)
      4. 8.6.4 Power Register (03h, Read-Only)
      5. 8.6.5 Current Register (04h, Read-Only)
      6. 8.6.6 Calibration Register (05h, Read/Write)
      7. 8.6.7 Mask/Enable Register (06h, Read/Write)
      8. 8.6.8 Alert Limit Register (07h, Read/Write)
  9. Application and Implementation
    1. 9.1 Application Information
      1. 9.1.1 Filtering and Input Considerations
    2. 9.2 Typical Applications
      1. 9.2.1 Design Requirements
      2. 9.2.2 Detailed Design Procedure
      3. 9.2.3 Application Curves
    3. 9.3 Power Supply Recommendations
    4. 9.4 Layout
      1. 9.4.1 Layout Guidelines
      2. 9.4.2 Layout Example
  10. 10Device and Documentation Support
    1. 10.1 Documentation Support
      1. 10.1.1 Related Documentation
    2. 10.2 Receiving Notification of Documentation Updates
    3. 10.3 Support Resources
    4. 10.4 Trademarks
    5. 10.5 Electrostatic Discharge Caution
    6. 10.6 Glossary
  11. 11Mechanical, Packaging, and Orderable Information

Package Options

Refer to the PDF data sheet for device specific package drawings

Mechanical Data (Package|Pins)
  • YFF|12
  • YFD|12
Thermal pad, mechanical data (Package|Pins)
Orderable Information

Power Calculation

The current and power are calculated after shunt voltage and bus voltage measurements, as shown in Figure 8-2. The current is calculated after a shunt voltage measurement based on the value set in the Calibration register. If there is no value loaded into the Calibration register, the current value stored is zero. Power is calculated following the bus voltage measurement based on the previous current calculation and bus voltage measurement. If there is no value loaded in the Calibration register, the power value stored is also zero. These calculations are performed in the background and do not add to the overall conversion time. These current and power values are considered intermediate results (unless the averaging is set to 1) and are stored in an internal accumulation register, not the corresponding output registers. Following every measured sample, the newly-calculated values for current and power are appended to this accumulation register until all of the samples have been measured and averaged based on the number of averages set in the Configuration register.

GUID-2ECFAD2F-9FE1-4606-8804-7E4311DD0F53-low.gifFigure 8-2 Power Calculation Scheme

In addition to the current and power accumulating after every sample, the shunt and bus voltage measurements are also collected. After all of the samples have been measured and the corresponding current and power calculations have been made, the accumulated average for each of these parameters is then loaded to the corresponding output registers where they can then be read.