SBOS576C May   2012  – September 2026 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
  9. 8 Register Maps
    1. 8.1 Summary of Register Set
    2. 8.2 Register Descriptions
      1. 8.2.1  Configuration Register (address = 00h) [reset = 7127h]
      2. 8.2.2  Channel-1 Shunt-Voltage Register (address = 01h), [reset = 00h]
      3. 8.2.3  Channel-1 Bus-Voltage Register (address = 02h) [reset = 00h]
      4. 8.2.4  Channel-2 Shunt-Voltage Register (address = 03h) [reset = 00h]
      5. 8.2.5  Channel-2 Bus-Voltage Register (address = 04h) [reset = 00h]
      6. 8.2.6  Channel-3 Shunt-Voltage Register (address = 05h) [reset = 00h]
      7. 8.2.7  Channel-3 Bus-Voltage Register (address = 06h) [reset = 00h]
      8. 8.2.8  Channel-1 Critical-Alert Limit Register (address = 07h) [reset = 7FF8h]
      9. 8.2.9  Warning-Alert Channel-1 Limit Register (address = 08h) [reset = 7FF8h]
      10. 8.2.10 Channel-2 Critical-Alert Limit Register (address = 09h) [reset = 7FF8h]
      11. 8.2.11 Channel-2 Warning-Alert Limit Register (address = 0Ah) [reset = 7FF8h]
      12. 8.2.12 Channel-3 Critical-Alert Limit Register (address = 0Bh) [reset = 7FF8h]
      13. 8.2.13 Channel-3 Warning-Alert Limit Register (address = 0Ch) [reset = 7FF8h]
      14. 8.2.14 Shunt-Voltage Sum Register (address = 0Dh) [reset = 00h]
      15. 8.2.15 Shunt-Voltage Sum-Limit Register (address = 0Eh) [reset = 7FFEh]
      16. 8.2.16 Mask/Enable Register (address = 0Fh) [reset = 0002h]
      17. 8.2.17 Power-valid Upper-limit Register (address = 10h) [reset = 2710h]
      18. 8.2.18 Power-Valid Lower-Limit Register (address = 11h) [reset = 2328h]
      19. 8.2.19 Manufacturer ID Register (address = FEh) [reset = 5449h]
      20. 8.2.20 Die ID Register (address = FFh) [reset = 3220]
  10. 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
    3. 9.3 Power Supply Recommendations
    4. 9.4 Layout
      1. 9.4.1 Layout Guidelines
      2. 9.4.2 Layout Example
  11. 10Device and Documentation Support
    1. 10.1 Device Support
      1. 10.1.1 Development Support
    2. 10.2 Documentation Support
      1. 10.2.1 Related Documentation
    3. 10.3 Receiving Notification of Documentation Updates
    4. 10.4 Support Resources
    5. 10.5 Trademarks
    6. 10.6 Electrostatic Discharge Caution
    7. 10.7 Glossary
  12. 11Revision History
  13. 12Mechanical, Packaging, and Orderable Information

7.5.2.1 High-Speed I2C Mode

When the bus is idle, the SDA and SCL lines are pulled high by the pull-up resistors. The controller generates a start condition followed by a valid serial byte with the high-speed (Hs) controller code 00001XXX. This transmission is made in fast (400kHz) or standard (100kHz) (F/S) mode at no more than 400kHz. The INA3221 does not acknowledge the Hs controller code, but does recognize the code and switches the internal filters to support 2.44MHz operation.

The controller then generates a repeated start condition (a repeated start condition has the same timing as the start condition). After this repeated start condition, the protocol is the same as F/S mode, except that transmission speeds up to 2.44MHz are allowed. Instead of using a stop condition, the controller uses a repeated start conditions to secure the bus in Hs mode. A stop condition ends the Hs mode, and switches all internal INA3221 filters to support F/S mode.

Figure 7-13 shows the bus timing, and Table 7-2 lists the bus timing definitions.

INA3221 Bus TimingFigure 7-13 Bus Timing
Table 7-2 Bus Timing Definitions(1)
PARAMETERFAST MODEHIGH-SPEED MODEUNIT
MINMAXMINMAX
f(SCL)SCL operating frequency0.0010.40.0012.44MHz
t(BUF)Bus free time between stop and start conditions1300160ns
t(HDSTA)Hold time after repeated START condition.
After this period, the first clock is generated.		600160ns
t(SUSTA)Repeated start condition setup time600160ns
t(SUSTO)STOP condition setup time600160ns
t(HDDAT)Data hold time00ns
t(VDDAT)Data valid time1200260ns
t(SUDAT)Data setup time10010ns
t(LOW)SCL clock low period1300270ns
t(HIGH)SCL clock high period60060ns
tfDAData fall time500150ns
tfCLClock fall time30040ns
trClock rise time30040ns
Clock rise time for SCLK ≤ 100kHz1000ns
(1) Values based on a statistical analysis of a one-time sample of devices. Minimum and maximum values are not production tested.
A0 = A1 = 0.