Design, Voltage Mode Control and Non-ideal Analysis of a Low Voltage-High Current Synchronous Buck Converter

Abstract

Synchronous and non-synchronous buck converters are uninsulated DC-DC converters which are widely used in any application that needs low voltage and high current. Switches are accepted as ideal during simulations of these converters in order to simplify the analysis. Non-ideal case can be analyzed by adding the resistances of switches and inductances as components to simulation. In this study, steady state and transient state are both analyzed for non-ideal case for continuous conduction mode by designing a 225 W synchronous buck converter. Simulations are performed in MATLAB/Simulink by calculated design parameters. A digital controller was designed according to simulation results in order to control the output voltage. Stability analysis for the designed converter was achieved. In the second part of the study, converter was manufactured and designed controller was embedded to a DSP based microcontroller. The performance of the system was investigated by testing the designed circuit under variable load and input voltage conditions and a comparison between simulation results for non-ideal case and practical results was made.

Keywords

• switch-mode power supply,converter,synchronous buck,transient state,steady state,stability,C2000 Piccolo LaunchPad

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