Two-Phase Coupled Inductor Inversion for PCB Layout Simplification

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing multi-phase DC-to-DC converters with coupled inductors face challenges due to complex and costly winding designs, which lead to high impedance and inefficient PCB layouts, particularly when achieving inverse magnetic coupling, necessitating separate switching circuit locations and complex trace configurations.

Innovation Solution

The development of a two-phase coupled inductor design with staple-style windings and a magnetic core configuration that allows for inverse magnetic coupling between windings, enabling all switching power stages to be disposed on a common side of the inductor, using short, wide, and simple PCB traces for terminal connections.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If complex winding designs are used to achieve inverse magnetic coupling, then magnetic coupling performance is improved, but manufacturing cost and impedance increase

Engineering Contradiction:
Improvemagnetic coupling performanceVSAvoidwinding design complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent inverts the conventional winding arrangement by placing both windings on the same side of the magnetic core rather than on opposite sides. This inversion achieves inverse magnetic coupling (where currents flow in opposite directions through the windings) while simplifying the winding design and reducing impedance, thereby resolving the contradiction between coupling performance and complexity.

Inventive Principle:
Principle #13The other way round (Inversion)

Solution Approach 2:

The patent employs asymmetric winding configuration where the two windings are positioned adjacently on one side of the core with different orientations - one winding wraps around the core while the other is positioned to create the inverse coupling effect. This asymmetric arrangement achieves the desired magnetic coupling performance with simpler, shorter windings that have lower impedance.

Inventive Principle:
Principle #4Asymmetry

2Reliability

If separate switching circuit locations are used to achieve inverse magnetic coupling, then magnetic coupling is improved, but PCB layout complexity increases

Engineering Contradiction:
Improvemagnetic couplingVSAvoidPCB layout complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent merges the switching circuits by allowing both to be located on the same side of the inductor component. The inductor is designed with all four terminals (two for each winding) accessible on one side, enabling both switching circuits to be positioned adjacently on the PCB without requiring separate locations on opposite sides of the component, thereby simplifying the PCB layout.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent transitions from a three-dimensional spatial separation (switching circuits on opposite sides of the inductor) to a two-dimensional planar arrangement (both switching circuits on the same side of the PCB). This dimensional change allows all switching power stages to be disposed on a common side while maintaining inverse magnetic coupling through the specially designed winding configuration.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

3Reliability

If complex trace configurations are used to connect terminals, then inverse magnetic coupling is achieved, but trace impedance and manufacturing complexity increase

Engineering Contradiction:
Improveinverse magnetic couplingVSAvoidPCB manufacturing simplicity
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent inverts the conventional terminal arrangement by bringing all four terminals to the same side of the inductor rather than having terminals on opposite sides. This inversion allows for simple, short PCB traces to connect all terminals without requiring complex trace configurations, thereby reducing trace impedance and simplifying manufacturing while maintaining inverse magnetic coupling.

Inventive Principle:
Principle #13The other way round (Inversion)

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 configuration reduces manufacturing costs, minimizes winding resistance, and simplifies PCB layouts by allowing all switching power stages to be on a single side, while maintaining efficient inverse magnetic coupling, thus improving the overall performance and reliability of the DC-to-DC converter.

Implementation Method 1

DC-to-DC converter 100 includes a coupled inductor 102, which includes two windings 104, 106, and a magnetic core 108 magnetically coupling windings 104, 106

Methodology Applied
Scientific EffectMagnetic coupling: Magnetic Field

Implementation Method 2

a current flowing through winding 104 from switching node 120 to common node 114 induces a current in winding 106 flowing from switching node 122 to common node 114

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Data Source

PatentEP2577691B1Two-phase coupled inductors which promote improved printed circuit board layout
Publication Date: 2017.01.04 VOLTERRA SEMICONDUCTOR CORPORATION
  • EP2577691B1 patent drawingFigure 1~3
  • EP2577691B1 patent drawingFigure 4~5
  • EP2577691B1 patent drawingFigure 6~7

AI summary

Two-phase coupled inductors including a magnetic core, at least a first winding, and at least three solder tabs. Power supplies including a printed circuit board, a two-phase coupled inductor affixed to the printed circuit board, and first and second switching circuits affixed to the printed circuit board. Each of the first and second switching circuits are electrically coupled to a respective solder tab of the two-phase coupled inductor affixed to the printed circuit board.