TIDUE18 November   2022 TPS51215A

 

  1.   Description
  2.   Resources
  3.   Features
  4.   Applications
  5.   5
  6. 1System Description
  7. 2System Overview
    1. 2.1 Block Diagram
    2. 2.2 Design Considerations
      1. 2.2.1 DCR current sense
      2. 2.2.2 Subtract and Amplify
      3. 2.2.3 Active Voltage Scale
      4. 2.2.4 IMON Output
    3. 2.3 Highlighted Products
    4. 2.4 System Design Theory
      1. 2.4.1 DCR Current Sense
      2. 2.4.2 Subtract and Amplify
      3. 2.4.3 Active Voltage Scale
      4. 2.4.4 IMON Output
  8. 3Hardware, Software, Testing Requirements, and Test Results
    1. 3.1 Hardware Requirements
    2. 3.2 Test Setup
    3. 3.3 Test Results
      1. 3.3.1 Start-up
      2. 3.3.2 VID Change
      3. 3.3.3 Load Transient
      4. 3.3.4 Load-Line Test
  9. 4Design and Documentation Support
    1. 4.1 Design Files
      1. 4.1.1 Schematics
      2. 4.1.2 BOM
      3. 4.1.3 PCB Layout Recommendations
      4. 4.1.4 Altium Project
      5. 4.1.5 Gerber Files
      6. 4.1.6 Assembly Drawings
    2. 4.2 Documentation Support
    3. 4.3 Support Resources
    4. 4.4 Trademarks
  10. 5About the Authors

2.4.3 Active Voltage Scale

Figure 2-6 Resistor Network for Voltage Scaling

The voltage scaling block to achieve output voltage load line is shown as Figure 2-6.

Based on superposition theorem:

Equation 1. V SNS = V o × R FB2 || R inject R FB1 + R FB2 || R inject + DROOP × R FB1 || R FB2 R inject + R FB1 || R FB2

Since VSNS=Vref and DC value of Vref is fixed in regulation, when load current becomes larger, DROOP will increase and VO will decrease.

The DROOP is proportional to output current, thus the decrease of VO is also proportional to output current, which corresponds to the load line needed.