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

3 Application Implementation

To demonstrate the practical implementation for the parallel operation of two buck-boost converters using LM51772 devices, an evaluation module is designed based on the block diagram shown in Figure 3-1. The designed setup has an overall power rating of 200W and an output voltage of 20V. Additionally, the selected peak current limit for each converter is 20A.

Block Diagram of Two LM51772 in Parallel OperationFigure 3-1 Block Diagram of Two LM51772 in Parallel Operation

The value for the external components used in the power stage and with LM51772 controller can easily selected by using the LM51772 Buck-Boost Quickstart Calculator Tool. These values need to be calculated for an individual power stage. Therefore, the total load current value can be divided by the number of power stages to calculate the external component values for each converter. Apart from this, some components required a special setting, as mentioned below.