TIDUF39 March   2025

 

  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
    2. 2.2 Design Considerations
    3. 2.3 Highlighted Products
      1. 2.3.1 DAC70502: Dual-Channel, 1-LSB INL, 14-Bit, SPI Voltage-Output Digital-to-Analog Converter (DAC)
      2. 2.3.2 INA818: 35μV Offset, 8nV/√Hz Noise, Low-Power, Precision Instrumentation Amplifier
      3. 2.3.3 OPA192: High-Voltage, Rail-to-Rail Input/Output, 5µV, 0.2µV/°C, Precision Operational Amplifier
      4. 2.3.4 LM5146: 100V Synchronous Buck DC/DC Controller With Wide Duty Cycle Range
  9. 3System Design Theory
    1. 3.1 Constant Current Control Design
    2. 3.2 Constant Current and Voltage Simulation
  10. 4Hardware, Software, Testing Requirements, and Test Results
    1. 4.1 Hardware Requirements
    2. 4.2 Software Requirements
    3. 4.3 Test Setup
      1. 4.3.1 Constant Current Test Setup
      2. 4.3.2 Constant Voltage Test Setup
    4. 4.4 Test Results
      1. 4.4.1 Current Control Accuracy
      2. 4.4.2 Voltage Control Accuracy
      3. 4.4.3 CC, CV Transformation
      4. 4.4.4 Constant Current Transient Response
      5. 4.4.5 Constant Voltage Transient Response
      6. 4.4.6 Voltage Ripple at Short Circuit
      7. 4.4.7 Tracking DC-DC output
  11. 5Design and Documentation Support
    1. 5.1 Design Files
      1. 5.1.1 Schematics
      2. 5.1.2 BOM
    2. 5.2 Tools and Software
    3. 5.3 Documentation Support
    4. 5.4 Support Resources
    5. 5.5 Trademarks
  12. 6About the Author

Voltage Control Accuracy

TIDA-010089 Voltage Loop Linearity TestFigure 4-7 Voltage Loop Linearity Test

Different current drawn from the load can also affect the CV control accuracy, a CV load regulation test is required. Table 4-3 shows the variation of constant current settings with respect to load voltage regulation. The data has minimal difference with the change in current.

Table 4-3 Voltage Regulation Under Different Currents
FS (V)15
VSET (V)1234.2815
CC MODE ISET (A)LOAD VOLTAGE (V)
0.10.9974231.997922.998274.198657.9985814.9975
10.997511.9982.998354.19877.998714.9977
20.997691.998192.998534.198887.9989114.9978
40.998011.998532.998864.199237.9992914.9981
60.9983781.998872.999224.199577.999714.9984
70.998551.999042.999414.199657.9997814.9985
ERROR (%FS)0.0115330.0138670.011530.0090.0094670.01667