Phase Waveform Extraction and Coupling Noise Prediction of Buck Converter in Printed Circuit Boards

Abstract

Buck DC-DC circuits are widely used in design of server PCB power supply, due to its fast switching voltage speed, the generation of phase noise is unavoidable, therefore, in order to design a stable system, it is important to extract the phase waveform and predict the phase coupling noise This paper presents a method for extracting phase waveforms and evaluating phase-coupled noise before the PCB Gerber Out. Methods as below (i) Construct a buck circuit simulation model, including voltage controller, MOSFET, PCB parasitics and capacitor RLC equivalent model for extracting phase waveform, and (ii) Combine phase waveform models, MOSFET models and PCB layout and simulation tools to simulate phase-coupled noise. Finally, the effectiveness and practicability of the evaluation method are verified by comparing the simulation results with the actual test results.