SBOS790A April   2017  – March 2025 INA233

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Pin Configuration and Functions
  6. 5 Specifications
    1. 5.1 Absolute Maximum Ratings
    2. 5.2 ESD Ratings
    3. 5.3 Recommended Operating Conditions
    4. 5.4 Thermal Information
    5. 5.5 Electrical Characteristics
    6. 5.6 Typical Characteristics
  7. 6 Detailed Description
    1. 6.1 Overview
    2. 6.2 Functional Block Diagram
    3. 6.3 Feature Description
      1. 6.3.1 High-Accuracy Analog-to-Digital Convertor (ADC)
      2. 6.3.2 Interleaved Power Calculation
      3. 6.3.3 Power Accumulator and Energy Measurement
      4. 6.3.4 I2C-, SMBus-, and PMBus-Compatible Digital Interface
      5. 6.3.5 Multiple Fault Event Reporting
    4. 6.4 Device Functional Modes
      1. 6.4.1 Continuous Verses Triggered Operation
      2. 6.4.2 Device Shutdown
      3. 6.4.3 Averaging and Conversion Time Considerations
      4. 6.4.4 Filtering and Input Considerations
    5. 6.5 Programming
      1. 6.5.1 Default Settings
      2. 6.5.2 Calibration Register and Scaling
      3. 6.5.3 Reading and Writing Telemetry Data and Warning Thresholds
      4. 6.5.4 Reading Telemetry Data and Warning Thresholds
        1. 6.5.4.1 Writing Telemetry Data and Warning Thresholds
      5. 6.5.5 System-Level Calibration With MFR_CALIRATION Command
      6. 6.5.6 Bus Overview
        1. 6.5.6.1 Serial Bus Address
        2. 6.5.6.2 Serial Interface
        3. 6.5.6.3 Writing to and Reading From the INA233
          1. 6.5.6.3.1 Packet Error Checking
          2. 6.5.6.3.2 Bus Timing Requirements
        4. 6.5.6.4 SMBus Alert Response
    6. 6.6 Register Maps
      1. 6.6.1 PMBus Command Support
      2. 6.6.2 Standard PMBus Commands
        1. 6.6.2.1  CLEAR_FAULTS (03h)
        2. 6.6.2.2  RESTORE_DEFAULT_ALL (12h)
        3. 6.6.2.3  CAPABILITY (19h)
        4. 6.6.2.4  IOUT_OC_WARN_LIMIT (4Ah) [default = 01111111 11111000]
        5. 6.6.2.5  VIN_OV_WARN_LIMIT (57h) [default = 01111111 11111000]
        6. 6.6.2.6  VIN_UV_WARN_LIMIT (58h) [default = 00000000 00000000]
        7. 6.6.2.7  PIN_OP_WARN_LIMIT (6Bh) [default = 11111111 11110000]
        8. 6.6.2.8  STATUS_BYTE (78h)
        9. 6.6.2.9  STATUS_WORD (79h)
        10. 6.6.2.10 STATUS_IOUT (7Bh)
        11. 6.6.2.11 STATUS_INPUT (7Ch)
        12. 6.6.2.12 STATUS_CML (7Eh)
        13. 6.6.2.13 STATUS_MFR_SPECIFIC (80h)
        14. 6.6.2.14 READ_EIN (86h)
        15. 6.6.2.15 READ_VIN (88h)
        16. 6.6.2.16 READ_IIN (89h)
        17. 6.6.2.17 READ_VOUT (8Bh)
        18. 6.6.2.18 READ_IOUT (8Ch, R)
        19. 6.6.2.19 READ_POUT (96h, R)
        20. 6.6.2.20 READ_PIN (97h, R)
        21. 6.6.2.21 MFR_ID (99h)
        22. 6.6.2.22 MFR_MODEL (9Ah)
        23. 6.6.2.23 MFR_REVISION (9Bh)
      3. 6.6.3 Manufacturer-Specific PMBus Commands
        1. 6.6.3.1 MFR_ADC_CONFIG (D0h) [default = 01000001 00100111]
        2. 6.6.3.2 MFR_READ_VSHUNT (D1h) [default = 00000000 00000000]
        3. 6.6.3.3 MFR_ALERT_MASK (D2h) [default = XXXXXXXX 11110000]
        4. 6.6.3.4 MFR_CALIBRATION (D4h) [default = 00000000 00000001]
        5. 6.6.3.5 MFR_DEVICE_CONFIG (D5h) [default = 00000010]
        6. 6.6.3.6 5.1.1 CLEAR_EIN (D6h)
        7. 6.6.3.7 TI_MFR_ID (E0h) [value = 01010100 01001001]
        8. 6.6.3.8 TI_MFR_MODEL (E1h) [value = 00110011 00110011]
        9. 6.6.3.9 TI_MFR_REVISION (E2h) [value = 01000001 00110000]
  8. 7 Application and Implementation
    1. 7.1 Application Information
    2. 7.2 Typical Application
      1. 7.2.1 Design Requirements
      2. 7.2.2 Detailed Design Procedure
        1. 7.2.2.1 Programming the Calibration Register
        2. 7.2.2.2 Calculating PMBus Coefficients
        3. 7.2.2.3 Programming Warning Thresholds
        4. 7.2.2.4 Calculating Returned Telemetry Values
      3. 7.2.3 Application Curves
    3. 7.3 Power Supply Recommendations
    4. 7.4 Layout
      1. 7.4.1 Layout Guidelines
      2. 7.4.2 Layout Example
  9. 8 Device and Documentation Support
    1. 8.1 Device Support
      1. 8.1.1 Development Support
    2. 8.2 Documentation Support
      1. 8.2.1 Related Documentation
    3. 8.3 Receiving Notification of Documentation Updates
    4. 8.4 Support Resources
    5. 8.5 Trademarks
    6. 8.6 Electrostatic Discharge Caution
    7. 8.7 Glossary
  10. 9 Revision History
  11. 10Mechanical, Packaging, and Orderable Information

7.2.2.2 Calculating PMBus Coefficients

The m, b, and R coefficients are fixed for bus voltage measurements returned by the READ_VIN and READ_VOUT and are available from Table 6-1.

For current and power measurements, the value for the m and R coefficients must be calculated. For current measurements returned by the READ_IIN and READ_IOUT commands, the value for m is calculated by inverting the Current_LSB used to set the MFR_CALIBRATION register and shifting the decimal location if needed to minimize rounding errors. In this example, using the Current_LSB of 1 mA/bit, the value of m is calculated to be 1000. Shifting the decimal location does not obtain higher accuracy because the value for m is a whole number. The value for R in this example is 0 because the decimal location for the value of m does not need shifting.

The POWER_LSB value is 25 times the value of the CURRENT_LSB, therefore, the value for m is reduced by a factor of 25. For this example, the value for the m power coefficient 1000 / 25 or 40. For this case, the R coefficient is also 0 because m is a whole number. If m is not a whole number, then shifting the decimal place is advantageous to reduce rounding errors while keeping the value between –32768 and 32767. Decimal shifts to the right result in negative values for R and shifts to the left result in positive values; the number of shifts is the absolute value of R.

The value of 0 can be used for b for both current and power measurements with very little loss in accuracy because the offset for power and current measurements is very low. The m, b, and R coefficients are fixed for bus voltage measurements returned by the READ_VIN and READ_VOUT and are available from Table 6-1.