Single-Inductor DC-DC Converter for Multiple Output Voltages

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Solution Overview

Problem

Existing DC-DC converters require multiple inductive energy storage devices to generate multiple output voltages, increasing hardware complexity, especially when the output voltage priorities are not predetermined.

Innovation Solution

A DC-DC converter design utilizing a single inductive energy storage device, with bidirectional high-side switching units and a control unit to manage energy distribution to multiple outputs based on decision criteria, preventing cross-currents and optimizing power loss.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If multiple inductive energy storage devices are used to generate multiple output voltages, then the ability to provide different output voltages is improved, but the hardware complexity increases

Engineering Contradiction:
Improveability to provide different output voltagesVSAvoidhardware complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The single inductor is designed to serve multiple output voltages through a multi-bridge circuit architecture. The inductor performs the same energy storage function for multiple different output voltage levels, eliminating the need for separate inductors for each output voltage, thus reducing hardware complexity while maintaining versatility

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The circuit employs dynamic switching control where electronic switches dynamically connect the single inductor to different output terminals based on the required output voltage. This dynamic reconfiguration allows one inductor to adaptively serve multiple output voltage requirements without requiring multiple fixed inductors

Inventive Principle:
Principle #15Dynamics

2Adaptability or versatility

If multiple inductive energy storage devices are used to generate multiple output voltages, then the output voltage flexibility is improved, but the efficiency deteriorates

Engineering Contradiction:
Improveoutput voltage flexibilityVSAvoidefficiency
Core Design Contradiction:
Adaptability or versatilityVSLoss of energy

Solution Approach 1:

Multiple bridge circuits are merged into a single integrated structure sharing one common inductor. This merging eliminates redundant energy storage and transfer operations that would occur with separate inductors, reducing energy losses while maintaining the ability to generate multiple output voltages

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The single inductor maintains continuous energy storage and transfer operations across multiple output voltages through coordinated switching. The inductor continuously cycles between charging from the input and discharging to different outputs, eliminating idle periods and reducing energy losses associated with switching between separate inductors

Inventive Principle:
Principle #20Continuity of useful action

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

Enables generation of multiple output voltages with reduced hardware complexity by using a single inductor, minimizing power loss, and efficiently managing energy distribution to meet varying output demands.

Implementation Method 1

an inductor, which is arranged between the connection nodes of the input and output half-bridges and which can be charged with electrical energy in a charging phase of one of several successive clocked control cycles and can be discharged in a discharging phase of a control cycle to forward electrical energy to one of the output terminals

Methodology Applied
Scientific EffectInductive energy storage: Inductor

Implementation Method 2

each high-side switch unit has a first electronic switch and a second electronic switch, each with a diode connected in parallel to the switch

Methodology Applied
Scientific EffectDiode rectification: Diode

Data Source

PatentEP4472047B1Dc-dc converter for converting an input voltage into at least two desired output voltages
Publication Date: 2026.04.22 ELMOS SEMICON AG
  • EP4472047B1 patent drawingFigure 1
  • EP4472047B1 patent drawingFigure 2
  • EP4472047B1 patent drawingFigure 3

AI summary

The invention relates to a DC-DC converter (DC converter) characterized, among other things, by the fact that only a single inductive energy storage device (hereinafter referred to as the inductor) is required to provide multiple output voltages. The multiple output half-bridges (AH1, AH2) have bidirectional high-side switching units (HSE1, HSE2), each connected between one of the output terminals (Vout1, Vout2) and a common connection node (VKAH). A low-side switch (M3), common to all output half-bridges (AH1, AH2), is located between the connection node (VKAH) and a reference potential terminal (GND). During the dead-time intervals in the switching phases or during commutation, one of the two electronic switches of the high-side switching unit (HSE1, HSE2) connected to the output terminal (Vout1, Vout2) to be supplied with electrical charge is closed.This switch is already closed during the charging phase. On the input side, the input voltage connection (Vin) is either coupled via the inductor (IND) to the connection node (VKAH) of the output half-bridges (AH1, AH2) or there is an input half-bridge (EH) with a high-side switch (M1) and a low-side switch (M2), whose common connection node (VKEH) is connected to the inductor (IND).