Multi-Level Power Converter With Inductor Bypass for Low-Loss Step-Down
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
There is a demand for high-efficiency, compact power converters with a small input-to-output voltage conversion ratio, particularly for applications like SSDs and wearable PMICs, where conventional buck converters are inefficient due to large inductor sizes and resistive losses.
Innovation Solution
A hybrid multi-level power converter design with a capacitive voltage divider and inductor bypass, utilizing a two-stage topology where a magnetizing current path and a parallel current path are established at different times to bypass the inductor, reducing resistive losses and achieving efficient power conversion with smaller components.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If conventional buck converters are used to achieve voltage conversion, then voltage regulation is provided, but inductor size and resistive losses increase area and reduce efficiency
Solution Approach 1:
The power conversion process is segmented into multiple discrete voltage levels (e.g., VIN, VIN/2, VIN/3, VOUT) achieved through series/parallel switching of capacitors. This segmentation eliminates the need for a large inductor by using capacitive voltage division and switching networks to step down voltage in stages, thereby reducing inductor size and resistive losses.
Solution Approach 2:
The inductor, which is the primary source of resistive losses and large area occupation in conventional buck converters, is extracted or removed from the circuit topology. The patent replaces the inductor-based energy storage and voltage transformation with a capacitor-based multi-level switching architecture, eliminating the harmful effects of inductor resistance while maintaining voltage conversion functionality.
2Productivity
If inductor-based buck converters are used for voltage conversion, then power conversion is achieved, but efficiency decreases due to resistive losses
Solution Approach 1:
The magnetic field-based inductor system is replaced with an electric field-based capacitor switching system. Instead of using inductors to store and transfer energy magnetically (which incur resistive losses), the patent uses capacitors to store energy electrically and switches them in series/parallel configurations to achieve voltage conversion, thereby eliminating resistive losses and improving power conversion efficiency.
Solution Approach 2:
The patent changes the operating parameters by using multiple voltage levels (e.g., VIN, VIN/2, VIN/3, VOUT) instead of direct buck conversion. By intermediate voltage steps and capacitive division, the current stress on individual components is reduced, and resistive losses are minimized, leading to higher overall efficiency.
3Area of stationary object
If conventional buck converter topology is used, then voltage regulation is provided, but area occupation increases due to large inductor and capacitor sizes
Solution Approach 1:
The patent introduces a temporal dimension to voltage regulation by using switching networks that dynamically reconfigure capacitor connections over time. Instead of relying on large passive components for voltage transformation, the system uses time-based switching of capacitors in series/parallel configurations to achieve multi-level voltage conversion, thereby reducing component sizes and overall converter area while maintaining regulation capability.
Solution Approach 2:
The capacitors in the patent serve multiple functions: voltage storage, voltage division, and active participation in voltage transformation through switching. This multi-functionality eliminates the need for separate large inductors and reduces the size of individual capacitors, as each capacitor contributes to both energy storage and voltage conversion, thereby reducing total converter area.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This design achieves higher efficiency and smaller area than conventional buck converters by bypassing the inductor during capacitive states, reducing resistive losses and eliminating the need for dedicated inductor current regulation, while maintaining efficient voltage regulation across flying capacitors.
Implementation Method 1
While in the magnetizing state, a current may flows along said magnetizing current path, resulting in a magnetic field generated by said inductor
Implementation Method 2
establish, in a magnetizing state, a magnetizing current path in the second stage from the intermediate node via the inductor to the output of the power converter
Implementation Method 3
The first stage may comprise a capacitive voltage divider with a first flying capacitor
Data Source
AI summary
The present document relates to power converters. A power converter has a first stage coupled between an input of the power converter and an intermediate node, and a second stage coupled between the intermediate node and an output of the power converter. The first stage has a capacitive voltage divider with a first flying capacitor, and the second stage has a second flying capacitor and an inductor. On the one hand, the power converter establishes, in a magnetizing state, a magnetizing current path in the second stage from the intermediate node via the inductor to the output of the power converter. On the other hand, the power converter establishes, in a capacitive state, a parallel current path in the second stage from the intermediate node via the second flying capacitor to the output of the power converter.