SBOSAC3B July   2023  – August 2025 INA745A , INA745B

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 Timing Requirements (I2C)
    7. 5.7 Timing Diagram
    8. 5.8 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 Integrated Shunt Resistor
      2. 6.3.2 Safe Operating Area
      3. 6.3.3 Versatile Measurement Capability
      4. 6.3.4 Internal Measurement and Calculation Engine
      5. 6.3.5 High-Precision Delta-Sigma ADC
        1. 6.3.5.1 Low Latency Digital Filter
        2. 6.3.5.2 Flexible Conversion Times and Averaging
      6. 6.3.6 Integrated Precision Oscillator
      7. 6.3.7 Multi-Alert Monitoring and Fault Detection
    4. 6.4 Device Functional Modes
      1. 6.4.1 Shutdown Mode
      2. 6.4.2 Power-On Reset
    5. 6.5 Programming
      1. 6.5.1 I2C Serial Interface
        1. 6.5.1.1 Writing to and Reading Through the I2C Serial Interface
        2. 6.5.1.2 High-Speed I2C Mode
        3. 6.5.1.3 SMBus Alert Response
  8. 7 Register Maps
    1. 7.1 INA745x Registers
  9. 8 Application and Implementation
    1. 8.1 Application Information
      1. 8.1.1 Device Measurement Range and Resolution
      2. 8.1.2 ADC Output Data Rate and Noise Performance
    2. 8.2 Typical Application
      1. 8.2.1 Design Requirements
      2. 8.2.2 Detailed Design Procedure
        1. 8.2.2.1 Configure the Device
        2. 8.2.2.2 Set Desired Fault Thresholds
        3. 8.2.2.3 Calculate Returned Values
      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 Documentation Support
      1. 9.1.1 Related Documentation
    2. 9.2 Receiving Notification of Documentation Updates
    3. 9.3 Support Resources
    4. 9.4 Trademarks
    5. 9.5 Electrostatic Discharge Caution
    6. 9.6 Glossary
  11. 10Revision History
  12. 11Mechanical, Packaging, and Orderable Information

6.3.2 Safe Operating Area

The heat generated by the device power dissipation limits the maximum current that can be safely handled by the package. The current consumed to power the device is low, therefore the primary source of heating is due to the current flow through the internal shunt resistor. The maximum safe-operating current level shown in Figure 6-4 is set to verify that the heat generated in the package is limited so that the internal junction temperature of the silicon does not exceed 150°C. This data is collected on the INA745x evaluation module (SENS109A).

INA745A INA745B Maximum Continuous Shunt Current vs Ambient Temperature Figure 6-4 Maximum Continuous Shunt Current vs Ambient Temperature

Even though the shunt can withstand currents greater than 35A, the current measurement capability is limited by ADC full scale range of 39.32A. The ADC full scale range is also a function of temperature (see Figure 8-1).

In applications with overcurrent transients, the peak amplitude and duration of the overcurrent event is important to determine the device heating. Figure 6-5 shows the peak pulse current versus pulse duration that the device can withstand before the maximum junction temperature of 150°C is exceeded. The data shown in this curve is collected at TA =-40°C, 25°C, and 125°C using the INA745x evaluation module (SENS109A).

INA745A INA745B Maximum Pulse Current vs Pulse Duration (Single Event) Figure 6-5 Maximum Pulse Current vs Pulse Duration (Single Event)