SLVAFW9 August   2024 LM51772

 

  1.   1
  2.   Abstract
  3.   Trademarks
  4. 1Introduction
  5. 2Parallel or Multiphase Power Stages
    1. 2.1 Paralleling Power Stages
      1. 2.1.1 Load Balancing Requirement
    2. 2.2 Clock Generation
    3. 2.3 Interconnection of the Power Stages
  6. 3Application Implementation
    1. 3.1 Soft-start Capacitor
    2. 3.2 Compensation
    3. 3.3 Input and Output Capacitor
    4. 3.4 Usage of the Average Current Sensor
  7. 4Test Results
    1. 4.1 Load Current Balancing
    2. 4.2 Inductor Current
    3. 4.3 Thermal Images
      1. 4.3.1 Dual Phase Operation at Variable Load
      2. 4.3.2 Comparison Between Single Phase and Dual Phase Operation
  8. 5Summary
  9. 6References

1 Introduction

The LM51772 device is a wide input voltage range, four-switch buck-boost controller IC with integrated drivers for N-channel MOSFETs.

One single LM51772 converter can deliver power greater than 200 W. To get higher output power, parallel power stages are needed to solve the excessive board heating problem because of the increased switching and conduction losses. Parallel operation of power stages can also provide many other benefits like: enhanced modularity, design flexibility, and minimized component ratings. These benefits can be realized only if the LM51772 converters evenly share the total load power. This application report shows how to configure and interconnect the LM51772 devices to get a well-balanced load-sharing. Test results show less than a 10% error in load sharing without sacrificing the overall performance.