SBOS776C March   2016  – March 2021 INA3221-Q1

PRODUCTION DATA  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Revision History
  5. 5 Device Comparison Table
  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 Electrical Characteristics
    6. 7.6 Typical Characteristics
  8. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1 Basic ADC Functions
      2. 8.3.2 Alert Monitoring
        1. 8.3.2.1 Critical Alert
          1. 8.3.2.1.1 Summation Control Function
        2. 8.3.2.2 Warning Alert
        3. 8.3.2.3 Power-Valid Alert
        4. 8.3.2.4 Timing-Control Alert
        5. 8.3.2.5 Default Settings
      3. 8.3.3 Software Reset
    4. 8.4 Device Functional Modes
      1. 8.4.1 Averaging Function
      2. 8.4.2 Multiple Channel Monitoring
        1. 8.4.2.1 Channel Configuration
        2. 8.4.2.2 Averaging and Conversion-Time Considerations
      3. 8.4.3 Filtering and Input Considerations
    5. 8.5 Programming
      1. 8.5.1 Bus Overview
        1. 8.5.1.1 Serial Bus Address
        2. 8.5.1.2 Serial Interface
      2. 8.5.2 Writing To and Reading From the INA3221-Q1
        1. 8.5.2.1 High-Speed I2C Mode
      3. 8.5.3 SMBus Alert Response
    6. 8.6 Register Maps
      1. 8.6.1 Summary of Register Set
      2. 8.6.2 Register Descriptions
        1. 8.6.2.1  Configuration Register (address = 00h) [reset = 7127h]
        2. 8.6.2.2  Channel-1 Shunt-Voltage Register (address = 01h), [reset = 00h]
        3. 8.6.2.3  Channel-1 Bus-Voltage Register (address = 02h) [reset = 00h]
        4. 8.6.2.4  Channel-2 Shunt-Voltage Register (address = 03h) [reset = 00h]
        5. 8.6.2.5  Channel-2 Bus-Voltage Register (address = 04h) [reset = 00h]
        6. 8.6.2.6  Channel-3 Shunt-Voltage Register (address = 05h) [reset = 00h]
        7. 8.6.2.7  Channel-3 Bus-Voltage Register (address = 06h) [reset = 00h]
        8. 8.6.2.8  Channel-1 Critical-Alert Limit Register (address = 07h) [reset = 7FF8h]
        9. 8.6.2.9  Warning-Alert Channel-1 Limit Register (address = 08h) [reset = 7FF8h]
        10. 8.6.2.10 Channel-2 Critical-Alert Limit Register (address = 09h) [reset = 7FF8h]
        11. 8.6.2.11 Channel-2 Warning-Alert Limit Register (address = 0Ah) [reset = 7FF8h]
        12. 8.6.2.12 Channel-3 Critical-Alert Limit Register (address = 0Bh) [reset = 7FF8h]
        13. 8.6.2.13 Channel-3 Warning-Alert Limit Register (address = 0Ch) [reset = 7FF8h]
        14. 8.6.2.14 Shunt-Voltage Sum Register (address = 0Dh) [reset = 00h]
        15. 8.6.2.15 Shunt-Voltage Sum-Limit Register (address = 0Eh) [reset = 7FFEh]
        16. 8.6.2.16 Mask/Enable Register (address = 0Fh) [reset = 0002h]
        17. 8.6.2.17 Power-Valid Upper-Limit Register (address = 10h) [reset = 2710h]
        18. 8.6.2.18 Power-Valid Lower-Limit Register (address = 11h) [reset = 2328h]
        19. 8.6.2.19 Manufacturer ID Register (address = FEh) [reset = 5449h]
        20. 8.6.2.20 Die ID Register (address = FFh) [reset = 3220]
  9. 9 Application and Implementation
    1. 9.1 Application Information
    2. 9.2 Typical Application
      1. 9.2.1 Design Requirements
      2. 9.2.2 Detailed Design Procedure
      3. 9.2.3 Application Curves
  10. 10Power Supply Recommendations
  11. 11Layout
    1. 11.1 Layout Guidelines
    2. 11.2 Layout Example
  12. 12Device and Documentation Support
    1. 12.1 Device Support
      1. 12.1.1 Development Support
    2. 12.2 Documentation Support
      1. 12.2.1 Related Documentation
    3. 12.3 Receiving Notification of Documentation Updates
    4. 12.4 Support Resources
    5. 12.5 Trademarks
    6. 12.6 Electrostatic Discharge Caution
    7. 12.7 Glossary
  13. 13Mechanical, Packaging, and Orderable Information

Package Options

Mechanical Data (Package|Pins)
Thermal pad, mechanical data (Package|Pins)
Orderable Information
8.3.2.1.1 Summation Control Function

The INA3221-Q1 also allows the Critical alert pin to be controlled by the summation control function. This function adds the single shunt-voltage conversions for the desired channels (set by SCC1-3 in the Mask/Enable register) in order to compare the combined sum to the programmed limit.

The SCC bits either disable the summation control function or allow the summation control function to switch between including two or three channels in the Shunt-Voltage Sum register. The Shunt-Voltage Sum Limit register contains the programmed value that is compared to the value in the Shunt-Voltage Sum register in order to determine if the total summed limit is exceeded. If the shunt-voltage sum limit value is exceeded, the Critical alert pin pulls low. Either the summation alert flag indicator bit (SF) or the individual critical alert limit bits (CF1-3) in the Mask/Enable register determine the source of the alert when the Critical alert pin pulls low.

For the summation limit to have a meaningful value, use the same shunt-resistor value on all included channels. Unless equal shunt-resistor values are used for each channel, do not use this function to add the individual conversion values directly together in the Shunt-Voltage Sum register to report the total current.