Clock Frequency Optimization of a Compensated Spread-Spectrum Controller in Buck Converters

This research investigates the spread-spectrum technique’s impact on buck converters, with a focus on electromagnetic emissions and output voltage ripple. The ripple, attributed to constant delay time in the PWM generator, induces changes in the duty cycle as the switching frequency varie...

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Main Authors: Jurica Kundrata, Adrijan Baric
Format: Article
Language:English
Published: IEEE 2024-01-01
Series:IEEE Access
Subjects:
Online Access:https://ieeexplore.ieee.org/document/10381686/
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author Jurica Kundrata
Adrijan Baric
author_facet Jurica Kundrata
Adrijan Baric
author_sort Jurica Kundrata
collection DOAJ
description This research investigates the spread-spectrum technique’s impact on buck converters, with a focus on electromagnetic emissions and output voltage ripple. The ripple, attributed to constant delay time in the PWM generator, induces changes in the duty cycle as the switching frequency varies due to the spread-spectrum technique. To alleviate this, a time delay compensation mechanism recalculated at each switching frequency change is proposed. To address duty cycle inaccuracies from integer calculations in a digital core, a remainder accumulator in time delay calculation is introduced. A numerical model parametrized by the controller’s clock frequency and spread-spectrum resolution examines duty cycle error, ripple, and EMI peak reduction. Findings indicate that the proposed compensator and accumulator reduce duty cycle error while maintaining comparable ripple and achieving similar EMI peak reduction. EMI peak reduction plateaus at higher clock frequencies, suggesting an optimal clock frequency. Experimental results from an FPGA prototype corroborate the model and simulations, showing substantial duty cycle error reduction, comparable ripple, and maximized EMI peak reduction. The study thus illustrates the spread-spectrum technique’s potential in buck converters, providing an optimal configuration for EMI reduction and minimizing duty cycle error and ripple.
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spelling doaj.art-a37775f1224747cc890cf41eac1ad73f2024-01-12T00:02:24ZengIEEEIEEE Access2169-35362024-01-01124881489110.1109/ACCESS.2024.335035510381686Clock Frequency Optimization of a Compensated Spread-Spectrum Controller in Buck ConvertersJurica Kundrata0https://orcid.org/0000-0003-1687-0548Adrijan Baric1https://orcid.org/0000-0001-5642-3086Faculty of Electrical Engineering and Computing, University of Zagreb, Zagreb, CroatiaFaculty of Electrical Engineering and Computing, University of Zagreb, Zagreb, CroatiaThis research investigates the spread-spectrum technique’s impact on buck converters, with a focus on electromagnetic emissions and output voltage ripple. The ripple, attributed to constant delay time in the PWM generator, induces changes in the duty cycle as the switching frequency varies due to the spread-spectrum technique. To alleviate this, a time delay compensation mechanism recalculated at each switching frequency change is proposed. To address duty cycle inaccuracies from integer calculations in a digital core, a remainder accumulator in time delay calculation is introduced. A numerical model parametrized by the controller’s clock frequency and spread-spectrum resolution examines duty cycle error, ripple, and EMI peak reduction. Findings indicate that the proposed compensator and accumulator reduce duty cycle error while maintaining comparable ripple and achieving similar EMI peak reduction. EMI peak reduction plateaus at higher clock frequencies, suggesting an optimal clock frequency. Experimental results from an FPGA prototype corroborate the model and simulations, showing substantial duty cycle error reduction, comparable ripple, and maximized EMI peak reduction. The study thus illustrates the spread-spectrum technique’s potential in buck converters, providing an optimal configuration for EMI reduction and minimizing duty cycle error and ripple.https://ieeexplore.ieee.org/document/10381686/DC-DC converterdigital designduty cycle rippleEMIspread-spectrum
spellingShingle Jurica Kundrata
Adrijan Baric
Clock Frequency Optimization of a Compensated Spread-Spectrum Controller in Buck Converters
IEEE Access
DC-DC converter
digital design
duty cycle ripple
EMI
spread-spectrum
title Clock Frequency Optimization of a Compensated Spread-Spectrum Controller in Buck Converters
title_full Clock Frequency Optimization of a Compensated Spread-Spectrum Controller in Buck Converters
title_fullStr Clock Frequency Optimization of a Compensated Spread-Spectrum Controller in Buck Converters
title_full_unstemmed Clock Frequency Optimization of a Compensated Spread-Spectrum Controller in Buck Converters
title_short Clock Frequency Optimization of a Compensated Spread-Spectrum Controller in Buck Converters
title_sort clock frequency optimization of a compensated spread spectrum controller in buck converters
topic DC-DC converter
digital design
duty cycle ripple
EMI
spread-spectrum
url https://ieeexplore.ieee.org/document/10381686/
work_keys_str_mv AT juricakundrata clockfrequencyoptimizationofacompensatedspreadspectrumcontrollerinbuckconverters
AT adrijanbaric clockfrequencyoptimizationofacompensatedspreadspectrumcontrollerinbuckconverters