TIDUEZ9B July   2022  – April 2023

 

  1.   Description
  2.   Resources
  3.   Features
  4.   Applications
  5.   5
  6. 1System Description
    1. 1.1 Isolated Current Measurement
    2. 1.2 Band-Pass Filter
    3. 1.3 Analog-to-Digital Conversion
    4. 1.4 Arc Detection Algorithm
    5. 1.5 Key System Specifications
  7. 2System Overview
    1. 2.1 Block Diagram
    2. 2.2 Design Considerations
      1. 2.2.1 Current Transformer Circuit
      2. 2.2.2 Analog Band-Pass Filter
      3. 2.2.3 Analog-to-Digital Conversion
      4. 2.2.4 Power Supply
      5. 2.2.5 Debugging and Status Indication Options
    3. 2.3 Highlighted Products
      1. 2.3.1 TPS259474
      2. 2.3.2 TPS562202
      3. 2.3.3 TPS745
      4. 2.3.4 OPAx322
      5. 2.3.5 ADS8363
      6. 2.3.6 REF5025
      7. 2.3.7 TMDSCNCD280049C
  8. 3Hardware, Software, Testing Requirements, and Test Results
    1. 3.1 Hardware and Software Requirements
      1. 3.1.1 Hardware
      2. 3.1.2 Software
        1. 3.1.2.1 Arc Detection Theory
        2. 3.1.2.2 Software Implementation
    2. 3.2 Test Setup
      1. 3.2.1 ControlCARD Configuration
      2. 3.2.2 Setup for Hardware and Software Validation
      3. 3.2.3 Setup for Arc Testing
    3. 3.3 Test Results
      1. 3.3.1 Test Results of Hardware and Software Validation
      2. 3.3.2 Testing With Arcs
  9. 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 Support Resources
    4. 4.4 Trademarks
  10. 5About the Author
  11. 6Revision History

3.1.2.2 Software Implementation

This section describes the basic functionality of the example software. The example software for the internal ADC implementation is available in the DigitalPower SDK. Request software supporting the ADS8363 from MySecureSoftware. This software is just for evaluation, since it only computes the arc noise in the defined frequency band, but does not implement any conditions or thresholds to indicate if there is arcing or not. The computed arc noise can be observed in the variable AD_result. With correct setup this value increases during an arcing condition.

The software implementation differs between the projects for evaluating the intern or the external ADC, but the general idea is the same. The software reads 1024 samples from the ADC and passes these samples then to the arc detection algorithm. Nearly all the sampling and data manipulation is done using background resources like the Direct Memory Access (DMA), to make sure that the arc detection is running continuously. The sampled data is stored in an array called CH1Data with the size of 1024. As soon as this array is filled up it is passed to the arc detection algorithm, which copies the values into a different memory location, to allow the CH1Data array to be filled up again by the DMA in the background, without corrupting the data used by the arc detection algorithm running in the foreground.

More details on how to control the software and how to observe these variables are found in Section 3.2.