Multi-Phase Buck Converter Ripple Cancellation Using Suppression Stages
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional multi-phase buck converters generate excessive ripple, which is inversely proportional to the number of phases and inductance, leading to inefficient dynamic voltage and frequency scaling, high costs, and large board area requirements.
Innovation Solution
Implementing a harmonic suppression buck converter with a different number of phases and inductances to cancel N-th harmonic currents, using integrated driver MOS switches and an intermediate supply voltage for optimal ripple cancellation, allowing for reduced inductance and capacitance while maintaining low ripple specifications.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If the number of phases and inductance are increased to reduce ripple, then the board area and cost increase, but the ripple reduction is insufficient
Solution Approach 1:
The system is divided into a main buck converter and a separate harmonic suppression buck converter. The suppression converter has M phases that are segmented to specifically target and cancel N-th harmonic currents from the main converter, achieving ripple reduction without proportionally increasing the total phase count and board area of the main converter.
Solution Approach 2:
The harmonic suppression buck converter acts as an intermediary system that generates suppression currents to cancel the harmful harmonic currents. This intermediary converter uses different inductance values and phase configurations to specifically target the N-th harmonics, reducing ripple without requiring the main converter to be oversized.
2Device complexity
If conventional multi-phase buck converters are used, then the system is simple in structure, but excessive ripple is generated
Solution Approach 1:
The power conversion system is segmented into two functional parts: the main buck converter for primary voltage conversion and the harmonic suppression buck converter for ripple cancellation. This segmentation allows each part to be optimized for its specific function, maintaining relative structural simplicity while achieving low ripple through coordinated operation.
Solution Approach 2:
The harmonic suppression buck converter serves as an intermediary that actively counteracts the harmful effects of the main converter. By generating suppression currents that are 180 degrees out of phase with the N-th harmonics, it cancels ripple without requiring fundamental changes to the main converter structure.
3Object-affected harmful factors
If larger inductance is used to reduce ripple, then the transient response becomes slower, but ripple is reduced
Solution Approach 1:
The system separates the ripple reduction function from the main power conversion path. The main converter can use smaller inductors for faster transient response, while the suppression converter handles ripple cancellation independently, allowing both fast response and low ripple to coexist without the traditional trade-off.
Solution Approach 2:
The suppression buck converter uses different inductance parameters (Lsup) compared to the main converter. By optimizing the inductance ratio and phase configuration, the system achieves ripple cancellation without being constrained by the inductance values needed for fast transient response in the main converter.
Data Source
AI summary
Methods and systems for ripple suppression in multi-phase buck converters may comprise a buck converter for providing an output voltage with controlled ripple current. The buck converter may include one or more main buck converter stages and one or more suppression buck converter stages coupled with the one or more main buck converter stages. The one or more suppression buck converter stages may provide suppression currents to reduce ripple currents generated in the one or main buck converter stages.