SBOS576C May   2012  – September 2025 INA3221

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Device Comparison Table
  6. 5 Pin Configuration and Functions
  7. 6 Specifications
    1. 6.1 Absolute Maximum Ratings
    2. 6.2 ESD Ratings
    3. 6.3 Recommended Operating Conditions
    4. 6.4 Thermal Information
    5. 6.5 Electrical Characteristics
    6. 6.6 Typical Characteristics
  8. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1 Basic ADC Functions
      2. 7.3.2 Alert Monitoring
        1. 7.3.2.1 Critical Alert
          1. 7.3.2.1.1 Summation Control Function
        2. 7.3.2.2 Warning Alert
        3. 7.3.2.3 Power-Valid Alert
        4. 7.3.2.4 Timing-Control Alert
        5. 7.3.2.5 Default Settings
      3. 7.3.3 Software Reset
    4. 7.4 Device Functional Modes
      1. 7.4.1 Averaging Function
      2. 7.4.2 Multiple Channel Monitoring
        1. 7.4.2.1 Channel Configuration
        2. 7.4.2.2 Averaging and Conversion-Time Considerations
      3. 7.4.3 Filtering and Input Considerations
    5. 7.5 Programming
      1. 7.5.1 Bus Overview
        1. 7.5.1.1 Serial Bus Address
        2. 7.5.1.2 Serial Interface
      2. 7.5.2 Writing To and Reading From the INA3221
        1. 7.5.2.1 High-Speed I2C Mode
      3. 7.5.3 SMBus Alert Response
    6. 7.6 Register Maps
      1. 7.6.1 Summary of Register Set
      2. 7.6.2 Register Descriptions
        1. 7.6.2.1  Configuration Register (address = 00h) [reset = 7127h]
        2. 7.6.2.2  Channel-1 Shunt-Voltage Register (address = 01h), [reset = 00h]
        3. 7.6.2.3  Channel-1 Bus-Voltage Register (address = 02h) [reset = 00h]
        4. 7.6.2.4  Channel-2 Shunt-Voltage Register (address = 03h) [reset = 00h]
        5. 7.6.2.5  Channel-2 Bus-Voltage Register (address = 04h) [reset = 00h]
        6. 7.6.2.6  Channel-3 Shunt-Voltage Register (address = 05h) [reset = 00h]
        7. 7.6.2.7  Channel-3 Bus-Voltage Register (address = 06h) [reset = 00h]
        8. 7.6.2.8  Channel-1 Critical-Alert Limit Register (address = 07h) [reset = 7FF8h]
        9. 7.6.2.9  Warning-Alert Channel-1 Limit Register (address = 08h) [reset = 7FF8h]
        10. 7.6.2.10 Channel-2 Critical-Alert Limit Register (address = 09h) [reset = 7FF8h]
        11. 7.6.2.11 Channel-2 Warning-Alert Limit Register (address = 0Ah) [reset = 7FF8h]
        12. 7.6.2.12 Channel-3 Critical-Alert Limit Register (address = 0Bh) [reset = 7FF8h]
        13. 7.6.2.13 Channel-3 Warning-Alert Limit Register (address = 0Ch) [reset = 7FF8h]
        14. 7.6.2.14 Shunt-Voltage Sum Register (address = 0Dh) [reset = 00h]
        15. 7.6.2.15 Shunt-Voltage Sum-Limit Register (address = 0Eh) [reset = 7FFEh]
        16. 7.6.2.16 Mask/Enable Register (address = 0Fh) [reset = 0002h]
        17. 7.6.2.17 Power-valid Upper-limit Register (address = 10h) [reset = 2710h]
        18. 7.6.2.18 Power-Valid Lower-Limit Register (address = 11h) [reset = 2328h]
        19. 7.6.2.19 Manufacturer ID Register (address = FEh) [reset = 5449h]
        20. 7.6.2.20 Die ID Register (address = FFh) [reset = 3220]
  9. 8 Application and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Application
      1. 8.2.1 Design Requirements
      2. 8.2.2 Detailed Design Procedure
      3. 8.2.3 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 Documentation Support
      1. 9.2.1 Related Documentation
    3. 9.3 Receiving Notification of Documentation Updates
    4. 9.4 Support Resources
    5. 9.5 Trademarks
    6. 9.6 Electrostatic Discharge Caution
    7. 9.7 Glossary
  11. 10Revision History
  12. 11Mechanical, Packaging, and Orderable Information

7.6.2.14 Shunt-Voltage Sum Register (address = 0Dh) [reset = 00h]

This register contains the sum of the single conversion shunt voltages of the selected channels based on the summation control bits 12, 13, and 14 in the Mask/Enable register.

This register is updated with the most recent sum following each complete cycle of all selected channels. The Shunt-Voltage Sum register LSB value is 40µV.

Table 7-31 Shunt-Voltage Sum Register
1514131211109876543210
SIGNSV13SV12SV11SV10SV9SV8SV7SV6SV5SV4SV3SV2SV1SV0—
R-0R-0R-0R-0R-0R-0R-0R-0R-0R-0R-0R-0R-0R-0R-0R-0
LEGEND: R/W = Read/Write; R = Read only; -n = value after reset
Table 7-32 Shunt-Voltage Sum Register Field Descriptions
BitFieldTypeResetDescription
15SIGNR0hSign bit.
0 = positive number
1 = negative number in twos complement format
14-1SV13-0R0hShunt-voltage sum data bits
0ReservedR0hReserved