SLVT229 December   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
      1. 2.2.1 High Side Gate Drive Circuit
      2. 2.2.2 PWM Generation Circuit
    3. 2.3 Highlighted Products
      1. 2.3.1 UCC21330-Q1 Overview
      2. 2.3.2 UCC27211A-Q1 Overview
      3. 2.3.3 TPS1212-Q1 Overview
  9. 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 Efficiency Data
      2. 3.3.2 Efficiency Graphs
      3. 3.3.3 Output Voltage Ripple
      4. 3.3.4 Thermal Images
      5. 3.3.5 Switch Voltage Stress of High Side Switches
      6. 3.3.6 Load Transients
      7. 3.3.7 Reverse Step-up Operation of SCC
  10. 4Design and Documentation Support
    1. 4.1 Design Files
      1. 4.1.1 PCB Layout Recommendations
    2. 4.2 Documentation Support
    3.     Trademarks

3.3.7 Reverse Step-up Operation of SCC

Reverse step-up operation is observed (shown in Figure 3-17) via the measurement on the SW node voltage of bias buck converter. Vsw here is an indication of whether the 48V on the input (which at the same time is the HV port of the SCC) has been established or not).

Here before the cursor "b" timestamp, the peak of SW node voltage has always been following the 12V input from the LV port (which is the output port for step-down operation).

After the "b" timestamp, the peak of SW node has risen as the reverse step-up operation is charging the HV port capacitors and raising HV voltage. By the time of the cursor "a" timestamp, the reverse operation has been done.

PMP41150 Reverse Operation, 1:4 Conversion Ratio, VLV = 12V, SCC Load = 300W.Figure 3-17 Reverse Operation, 1:4 Conversion Ratio, VLV = 12V, SCC Load = 300W.