JAJU875 July   2020

 

  1.   概要
  2.   リソース
  3.   特長
  4.   アプリケーション
  5.   5
  6. 1System Description
    1. 1.1 Key System Specifications
  7. 2System Overview
    1. 2.1 ブロック図
    2. 2.2 Design Considerations
    3. 2.3 Highlighted Products
      1. 2.3.1 TPS62864
      2. 2.3.2 TPS62088
      3. 2.3.3 TLV73318
    4. 2.4 System Design Theory
      1. 2.4.1 Designing Buck Converter Circuit TPS62864
      2. 2.4.2 Designing Buck Converter Circuit TPS62088
      3. 2.4.3 Designing Buck Converter Circuit TLV73318
  8. 3Hardware, Software, Testing Requirements, and Test Results
    1. 3.1 Testing and Results
      1. 3.1.1 Test Setup
      2. 3.1.2 Test Results
        1. 3.1.2.1 Startup with no load
        2. 3.1.2.2 Load Transient Rail SoC 0.9V
        3. 3.1.2.3 Load Transient Rail NAND I/O 1.2 V
        4. 3.1.2.4 Load Transient Rail NAND VCC 2.5 V
        5. 3.1.2.5 Output Ripple Rail SoC 0.9 V
        6. 3.1.2.6 Output Ripple Rail NAND I/O 1.2 V
        7. 3.1.2.7 Output Ripple Rail NAND VCC 2.5 V
        8. 3.1.2.8 Output Ripple Rail SOC I/O 1.8 V
        9. 3.1.2.9 Efficiency
  9. 4Design Files
    1. 4.1 Schematics
    2. 4.2 Bill of Materials
    3. 4.3 PCB Layout Recommendations
      1. 4.3.1 Layout Prints
    4. 4.4 Altium Project
    5. 4.5 Gerber Files
    6. 4.6 Assembly Drawings
  10. 5Software Files
  11. 6Related Documentation
    1. 6.1 Trademarks
    2. 6.2 Third-Party Products Disclaimer

2.4.1 Designing Buck Converter Circuit TPS62864

GUID-8159F505-4711-409D-B499-9AA33434B130-low.gifFigure 2-4 Designing Buck Converter Circuit TPS62864

To support a simple evaluation, a tantalum input capacitor C3 is used to ensure a steady, low-impedance supply voltage for the ICs.

Also, to achieve a smaller package size, the GRM155R60J226ME11 22uF 0402 capacitors were used in C2, C4, and C5. The recommended minimum input capacitance for this device is 8uF. According to the characteristics of this capacitor, this would mean that the maximum input voltage should be 3.3 V to ensure that C2 effective capacitance is 8uF. Similar considerations were applied for the TPS62088 designs.