Comprehensive Analysis and Design of Current-Balance Loop in Constant On-Time Controlled Multi-Phase Buck Converter

Constant on-time (COT) controlled multi-phase buck converter has been widely used in high-current applications such as computing devices to achieve high entire-load-range efficiency. However, the literature lacks comprehensive analysis and design guide of the current-balance loop in COT control, res...

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Bibliographic Details
Main Authors: Ching-Jan Chen, Zih-Yuan Zeng, Ching-Hsiang Cheng, Fu-To Lin
Format: Article
Language:English
Published: IEEE 2020-01-01
Series:IEEE Access
Subjects:
Online Access:https://ieeexplore.ieee.org/document/9229205/
Description
Summary:Constant on-time (COT) controlled multi-phase buck converter has been widely used in high-current applications such as computing devices to achieve high entire-load-range efficiency. However, the literature lacks comprehensive analysis and design guide of the current-balance loop in COT control, resulting in possible low efficiency, per-phase current protection false-trigger, and stability issue. To solve the aforementioned issues, dc inductor current equations and small-signal models are proposed for COT control with the current-balance loop. Current-balance loop gain design guideline is then proposed to achieve accurate dc current balance and stability. Experiment and simulation results verify the analysis and the accuracy of the proposed models.
ISSN:2169-3536