TIDUF85A August   2024  – December 2024

 

  1.   1
  2.   Description
  3.   Resources
  4.   Features
  5.   Applications
  6.   6
  7. 1System Description
    1. 1.1 Key System Specifications
  8. 2System Overview
    1. 2.1 Block Diagram
      1. 2.1.1 Subsystems
        1. 2.1.1.1 Arc Detection Channels
          1. 2.1.1.1.1 Isolated Current Measurement
          2. 2.1.1.1.2 Band-Pass Filter
          3. 2.1.1.1.3 Analog-to-Digital Conversion
          4. 2.1.1.1.4 Arc Detection Using Embedded AI Models
        2. 2.1.1.2 Arc Labeling Circuit
          1. 2.1.1.2.1 Isolated String Voltage Measurement
          2. 2.1.1.2.2 Isolated Arc Voltage Measurement With Isolated Comparator
          3. 2.1.1.2.3 Window Comparator for Advanced Labeling
    2. 2.2 Design Considerations
      1. 2.2.1 Current Sensor and Input Stage
      2. 2.2.2 Analog Band-Pass Filter
      3. 2.2.3 Arc-Labeling Circuit
        1. 2.2.3.1 String Voltage Sensing
        2. 2.2.3.2 Arc Gap Voltage Sensing
        3. 2.2.3.3 Differential to Single-Ended Conversion
        4. 2.2.3.4 Window Comparator for Arc Labeling
      4. 2.2.4 Auxiliary Power Supply
      5. 2.2.5 controlCard and Debug Interface
    3. 2.3 Highlighted Products
      1. 2.3.1 TIEVM-ARC-AFE
      2. 2.3.2 TMDSCNCD28P55X – TMDSCNCD28P55X controlCARD Evaluation Module
        1. 2.3.2.1 Hardware Features
      3. 2.3.3 OPA4323 – Quad, 5.5V, 20MHz, Zero-Cross Low-Noise (6nV/√Hz) RRIO Operational Amplifier
      4. 2.3.4 OPA323 – Single, 5.5V, 20MHz, Zero-Cross Low-Noise (6nV/√Hz) RRIO Operational Amplifier
      5. 2.3.5 AMC3330 – ±1V Input, Precision Voltage Sensing Reinforced Isolated Amplifier With Integrated DC/DC
      6. 2.3.6 AMC23C11 – Fast-Response, Reinforced, Isolated Comparator With Adjustable Threshold and Latch Function
  9. 3Hardware, Testing Requirements, and Test Results
    1. 3.1 Signal Chain Verification
      1. 3.1.1 Hardware Requirements
      2. 3.1.2 Test Setup
      3. 3.1.3 Test Results
    2. 3.2 Arc Testing
  10. 4Design and Documentation Support
    1. 4.1 Design Files
      1. 4.1.1 Schematics
      2. 4.1.2 BOM
    2. 4.2 Tools and Software
    3. 4.3 Documentation Support
    4. 4.4 Support Resources
    5. 4.5 Trademarks
  11. 5About the Author
  12. 6Revision History

2.3.4 OPA323 – Single, 5.5V, 20MHz, Zero-Cross Low-Noise (6nV/√Hz) RRIO Operational Amplifier

The OPAx323 family of op amps includes single (OPA323), dual (OPA2323), and quad-channel (OPA4323), low-voltage (1.7V to 5.5V), high-bandwidth (20MHz) amplifiers (op amps) with a zero-crossover input stage and a rail-to-rail output stage. The zero-crossover input stage enables OPAx323 to achieve high linearity and low distortion for input signals with rail-to-rail swing that are typical in ADC driver applications. Gain-bandwidth of 20MHz provides a fast settling response for ADC sampling speeds between 0.5MSPS to 5MSPS depending on the settling performance required. The OPAx323 is well-optimized for power savings as the device consumes just 1.6mA typical quiescent current.

The OPAx323 easily supports precision performance in high gain voltage sensing applications such as the Wheatstone bridge, as the device features maximum offset drift of 2µV/°C and thermal noise floor of 5.5nV/rt-Hz with a minimum of 100dB CMRR. This unique combination of higher precision (low offset, drift, noise, distortion, and CMRR) and higher gain-bandwidth (fast settling and slewing) enables use in multiple applications such as the motor rotary encoders, microphone audio pre-amplifiers and ultrasonic transducers.

The OPAx323 achieves a high slew-rate of 33V/µs allowing for fast detection of faults in motor current sensing applications. Unlike traditional amplifiers, the zero-cross over input stage allows for identical precision performance for both low and high-side sensing applications, thus making OPAx323 the best choice for current sensing in a variety of end equipments such as the solar string inverters, power delivery, grid and EV infrastructure. OPAx323S devices provide shutdown functionality for additional power savings and help disable the amplifier when idle. The family features standard and small size as well as leaded and QFN packages across all the channel variants.