SBOSAC3A July   2023  – December 2023 INA745A , INA745B

PRODMIX  

  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 Application and Implementation
    1. 7.1 Application Information
      1. 7.1.1 Device Measurement Range and Resolution
      2. 7.1.2 ADC Output Data Rate and Noise Performance
    2. 7.2 Typical Application
      1. 7.2.1 Design Requirements
      2. 7.2.2 Detailed Design Procedure
        1. 7.2.2.1 Configure the Device
        2. 7.2.2.2 Set Desired Fault Thresholds
        3. 7.2.2.3 Calculate Returned 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
    5. 7.5 Register Maps
      1. 7.5.1 INA745x Registers
  9. 8 Device and Documentation Support
    1. 8.1 Receiving Notification of Documentation Updates
    2. 8.2 Support Resources
    3. 8.3 Trademarks
    4. 8.4 Electrostatic Discharge Caution
    5. 8.5 Glossary
  10. 9 Revision History
  11. 10Mechanical, Packaging, and Orderable Information

Package Options

Mechanical Data (Package|Pins)
Thermal pad, mechanical data (Package|Pins)
Orderable Information

7.1.2 ADC Output Data Rate and Noise Performance

The INA745x noise performance and effective resolution depend on the ADC conversion time. The device also supports digital averaging which can further help decrease digital noise. The flexibility of the device to select ADC conversion time and data averaging offers increased signal-to-noise ratio and achieves the highest dynamic range with lowest offset. The profile of the noise at lower signals levels is dominated by the system noise that is comprised mainly of 1/f noise or white noise. The INA745x effective resolution of the ADC can be increased by increasing the conversion time and increasing the number of averages.

Table 7-2 summarizes the output data rate conversion settings supported by the device. The fastest conversion setting is 50 µs. Typical noise-free resolution is represented as Effective Number of Bits (ENOB) based on device measured data. The ENOB is calculated based on noise peak-to-peak values, which assures that full noise distribution is taken into consideration.

Table 7-2 INA745x Noise Performance
ADC CONVERSION TIME PERIOD [µs] OUTPUT SAMPLE AVERAGING [SAMPLES] OUTPUT SAMPLE PERIOD [ms] NOISE-FREE ENOB CURRENT MEASUREMENT
50 1 0.05 9.9
84 0.084 10.3
150 0.15 10.9
280 0.28 11.8
540 0.54 12.0
1052 1.052 12.5
2074 2.074 13.1
4120 4.12 13.7
50 4 0.2 11.1
84 0.336 11.4
150 0.6 12.1
280 1.12 12.8
540 2.16 13.4
1052 4.208 13.7
2074 8.296 14.7
4120 16.48 14.7
50 16 0.8 12.2
84 1.344 13.1
150 2.4 13.4
280 4.48 13.7
540 8.64 14.1
1052 16.832 14.7
2074 33.184 15.7
4120 65.92 15.7
50 64 3.2 13.1
84 5.376 13.7
150 9.6 14.1
280 17.92 14.7
540 34.56 15.7
1052 67.328 15.7
2074 132.736 15.7
4120 263.68 15.7
50 128 6.4 13.4
84 10.752 14.1
150 19.2 14.7
280 35.84 15.7
540 69.12 15.7
1052 134.656 15.7
2074 265.472 15.7
4120 527.36 15.7
50 256 12.8 14.1
84 21.504 14.7
150 38.4 15.7
280 71.68 15.7
540 138.24 15.7
1052 269.312 15.7
2074 530.944 15.7
4120 1054.72 15.7
50 512 25.6 14.1
84 43 15.7
150 76.8 15.7
280 143.36 15.7
540 276.48 15.7
1052 538.624 15.7
2074 1061.888 15.7
4120 2109.44 16.0
50 1024 51.2 15.7
84 86.016 15.7
150 153.6 15.7
280 286.72 15.7
540 552.96 15.7
1052 1077.248 15.7
2074 2123.776 16.0
4120 4218.88 16.0