SLVAFK5A December   2023  – February 2024 LM5177

 

  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
  10. 7Revision History

Dual Phase Operation at Variable Load

To verify the thermal stability of the EVM with parallel operation and load sharing, thermal images (Figure 4-11 to Figure 4-18) are taken of EVM for normal and extreme load conditions under different LM5177 converter topologies. The maximum operating temperature of LM5177 is 120 degrees Celsius. The results show that the maximum load current capability in boost mode is limit to 12 A because of the peak current limiter, and have a high temperature under extreme load (12 A) conditions compared to the buck and buck-boost modes.

GUID-20230424-SS0I-GZVW-3BV2-BTC947T2DWXS-low.jpgFigure 4-11 Thermal Condition in Boost Region (VIN=8 V and 8 A Load)
GUID-20230424-SS0I-G2XC-P1GF-PKKZRV7BKNH8-low.jpgFigure 4-13 Thermal Condition in Boost Region (VIN=10 V and 8 A Load)
GUID-20230424-SS0I-CC1D-RBSV-H9LFKP5MQR6M-low.jpgFigure 4-15 Thermal Condition in Buck-Boost Region (VIN=16 V and 8 A Load)
GUID-20230424-SS0I-969W-RKHV-VC7RJNKMHRML-low.jpgFigure 4-17 Thermal Condition in Buck Region (VIN=24 V and 8 A Load)
GUID-20230424-SS0I-HZZP-2WRX-KXQDXSTFFML2-low.jpgFigure 4-12 Thermal Condition in Boost Region (VIN=8 V and 12 A Load)
GUID-20230424-SS0I-PXK4-7HWQ-QK85CTPBVDFB-low.jpgFigure 4-14 Thermal Condition in Boost Region (VIN=10 V and 14 A Load)
GUID-20230424-SS0I-TQCL-ZV4M-DN6LTXN5M2KW-low.jpgFigure 4-16 Thermal Condition in Buck-Boost Region (VIN=16 V and 18 A Load)
GUID-20230424-SS0I-SW1D-R005-14DNSGTPLWWD-low.jpgFigure 4-18 Thermal Condition in Buck Region (VIN=24 V and 18 A Load)