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

1.3 Analog-to-Digital Conversion

This design offers the evaluation of an external ADC and the internal ADC of the C2000 MCU. In general, the ADC has to sample with at least double the frequency of the analyzed frequency range, to fulfill the sampling theorem. With a frequency band of 30 kHz to 100 kHz, a sampling speed of 250 kSPS is selected in this design. Furthermore, up to four independent channels have to be sampled continuously, which means a sampling speed of 1 MSPS is required as a minimum. As an external ADC, the ADS8363 is chosen. This 8-channel 16-bit device allows sampling with up to 2 MSPS and is interfaced via SPI to the C2000 MCU. As an alternative the internal ADC of the C2000 MCU can be used. The specifications on the internal ADC vary between versions. The TMS320F280049C, for example, provides three 3.45 MSPS 12-bit ADCs, which support 7 inputs each.