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

6.3.1 High-Accuracy Analog-to-Digital Convertor (ADC)

The INA233 integrates a highly accurate, 16-bit, delta-sigma (ΔΣ) ADC. This ADC is multiplexed to process both the shunt voltage and bus voltage measurements. The shunt voltage measurement is a differential measurement of the voltage developed when the load current flows through a shunt resistor as measured at the IN+ and IN– pins. The shunt voltage measurement has an maximum offset voltage of only 10 µV and a maximum gain error of only 0.1%. The low offset voltage of the shunt voltage measurement allows for increased accuracy at light load conditions for a given shunt resistor value. Another advantage of low offset is the ability to sense lower voltage drop across the sense resistor accurately, thus allowing for a lower-value shunt resistor. Lower-value shunt resistors reduce power loss in the current-sense circuit and help improve the power efficiency of the end application. The device can also measure the power-supply bus voltage by connecting this voltage to the VBUS pin. Internally, the voltage at VBUS is divided down to a voltage that can be measured by the ADC. The impedance of the VBUS pin to ground is approximately 830 kΩ. The differential shunt voltage is measured between the IN+ and IN– pins and the bus voltage is measured between the VBUS pin and GND.

The device takes two measurements: shunt voltage and bus voltage. The INA233 then converts these measurements to current, based on the calibration register value, and then calculates power; see the Calibration Register and Scaling section for additional information on programming the calibration register.

Although the device can be read at any time, and the data from the last conversion remain available, the conversion ready flag bit (MFR_ALERT_MASK, conversion ready bit) is provided to help coordinate one-shot or triggered conversions. The conversion ready bit is set after all conversions, averaging, and multiplication operations are complete.

The conversion ready bit clears under these conditions:

  • Writing to the MFR_ADC_CONFIG register, except when configuring the MODE bits for power-down mode; or
  • Reading the MFR_ALERT_MASK register