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 Critical Alert

The critical-alert feature monitors functions based on individual conversions of each shunt-voltage channel. The critical-alert limit feature compares the shunt-voltage conversion for each shunt-voltage channel to the value programmed into the corresponding limit register, in order to determine if the measured value exceeds the intended limit. Exceeding the programmed limit indicates that the current through the shunt resistor is too high.

At power-up, the default critical-alert limit value for each channel is set to the positive full-scale value, effectively disabling the alert. Program the corresponding limit registers at any time to begin monitoring for out-of-range conditions. The Critical alert pin pulls low if any channel measurement exceeds the limit present in the corresponding-channel critical-alert limit register. When the Critical alert pulls low, read the Mask/Enable register to determine which channel caused the critical alert flag indicator bit (CF1-3) to assert (= 1).