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

2.2.1 High Side Gate Drive Circuit

In this reference design, Q5 to Q10 can be regarded as three half-bridges with the low-side FET ground referenced; hence gate driving is much more straight forward and can be done with half-bridge gate driver like UCC27211A-Q1 used in the system.

However, Q1, Q2, Q3, and Q4 in the circuit need special gate drive strategy, since the source of these four switches is not ground-referenced. Therefore, an isolated dual-channel gate driver UCC21330A-Q1 is used to drive these four switches.

PMP41150 High Side Gate Drive CircuitFigure 2-2 High Side Gate Drive Circuit

In addition, a cascaded bootstrap circuit is needed. D8, D7, D6 and D5 are used to provide stable gate drive bias voltage for driving Q1, Q2, Q3 and Q4. To encounter the voltage drop in diode along the cascaded bootstrap path, UCC21330A-Q1 is selected due to having the lowest UVLO voltage at 5V compared to other versions in UCC21330-Q1 family.

An optional diode D1 is also added in parallel to the internal diode within UCC27211-Q1. Due to the high switching frequency and the number of high side MOSFETs, the current stress of internal bootstrap diode is higher than the usual use case. An additional parallel diode can help with the resulting increased voltage drop.