Efficiency and EMI simulation for l6565 based Quasi-resonant (QR) ZVS flyback converter

Sophia Li

Introduction:
Efficiency and EMI are two important aspects in power converters. Saber simulator has good modeling and simulation ability to analyses these in virtual mode. This demo is using QR ZVS flyback converter example comes from ST Microelectronics application note AN13261. L6565 quasi-resonant (QR) controller is used in this design.
In the “L6565 modeling and Quasi-resonant (QR) ZVS flyback converter simulation” example, L6565 modeling process is described, using switch for Power MOSFET and linear transformer. In this example, for efficiency simulation, Power MOSFET stp7nb80 and transformer are modeled using Saber. The efficiency simulation result fits well with real test result.
In the circuit test process, using experiments to run time domain analysis, checked different input voltage, full load and half load work status. Then checked the full load efficiency and EMI.

Circuit Snapshot:
Refer to the attached snapshot “l6565_flyback_level2.png”

How to use the example:
Download the attached l6565_flyback_level2.zip file and unzip the contents. Open the flyback2.ai_dsn in SaberRD and run all the experiments in the Experiment Analyzer tool. After simulation, look at the generated graph and experiment report.
For more details of the design, how to run the simulation, etc., refer to the README.pdf file in the folder.

Note:
This design works only in SaberRD commercial edition 2016.03 and above.