Buck Switcher with Integrated Boost Functionality

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Solution Overview

Problem

Conventional electronic devices that require both buck and boost switchers face challenges in minimizing size and cost due to the need for separate inductors, which occupy significant board space and increase production costs.

Innovation Solution

A buck switcher with integrated boost functionality that shares a single inductor and avoids series-coupled switches in the buck current path, allowing for both buck and boost modes without compromising performance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If separate buck and boost switchers are implemented, then both buck and boost functionality are provided, but board space is significantly increased

Engineering Contradiction:

Improvebuck and boost functionalityVSAvoidboard space

Core Design Contradiction:

Adaptability or versatilityVSArea of stationary object

Solution Approach 1:

The patent combines both buck and boost switcher functionalities into a single integrated circuit device. The buck switcher and boost switcher share common components including the inductor, high-side switch, low-side switch, and control logic, allowing both voltage step-down and voltage step-up operations from a single power supply voltage to serve different load requirements.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The integrated switcher device performs multiple functions by operating in different modes. The same physical components (inductor, switches, capacitors) are utilized for both buck operation (when load voltage is less than power supply voltage) and boost operation (when load voltage exceeds power supply voltage), making the device universal for different voltage conversion needs.

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Adaptability or versatility

If separate buck and boost switchers are implemented, then both buck and boost functionality are provided, but production cost is increased

Engineering Contradiction:

Improvebuck and boost functionalityVSAvoidproduction cost

Core Design Contradiction:

Adaptability or versatilityVSEase of manufacture

Solution Approach 1:

The patent merges two separate switcher circuits into one integrated device, reducing the total component count. Shared components include the inductor, high-side and low-side switches, control logic, and supporting capacitors, which eliminates the need for duplicate components and reduces assembly steps, thereby lowering production costs.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The integrated switcher provides both buck and boost functionality through a single device that can operate in different modes based on control signals. This multi-functionality eliminates the need to manufacture and stock separate buck and boost switcher devices, simplifying the supply chain and reducing overall production costs.

Inventive Principle:

Principle #6Universality (Multi-functionality)

3Adaptability or versatility

If series-coupled switches are used in the buck current path, then boost functionality is added, but additional resistance is introduced compromising buck performance

Engineering Contradiction:

Improveboost functionalityVSAvoidbuck performance

Core Design Contradiction:

Adaptability or versatilityVSReliability

Solution Approach 1:

The patent uses dynamic switching control where the high-side and low-side switches are activated based on the operating mode (buck or boost). During buck operation, the switches are configured to minimize resistance in the current path. During boost operation, the same switches are reconfigured through control logic to enable voltage step-up, optimizing performance for each mode without permanently degrading the other.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The switcher circuit changes its electrical parameters (switching states, current paths, duty cycle) dynamically based on the desired operation mode. By adjusting the control parameters and switching configurations, the circuit achieves both buck and boost functionality while maintaining optimal performance characteristics for each mode, avoiding fixed resistance compromises.

Inventive Principle:

Principle #35Parameter changes

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 approach minimizes board space and reduces costs by using shared components, while maintaining performance by avoiding additional resistance in the buck current path.

Implementation Method 1

both a magnetic buck switcher and a magnetic boost switcher generally use an inductor

Methodology Applied

Scientific EffectElectromagnetic induction: Electromagnetic Induction

Data Source

PatentUS8093874B1Method and system for adding boost functionality to a buck switcher with minimal cost

Publication Date: 2012.01.10 NAT SEMICON CORP

AI summary

A buck (with boost) switcher is provided that adds boost functionality to a buck switcher without compromising the buck's performance with extra series-coupled switches nor requiring a second inductor. The switcher has an integrated circuit that is capable of receiving a power supply voltage and a mode signal and generating on separate outputs either a boost voltage or a buck voltage based on the power supply voltage and the mode signal. The mode signal corresponds to one of a buck mode and a boost mode. The switcher also has a single inductor that is coupled to the integrated circuit and is capable of being used by the integrated circuit to generate the boost voltage (or a high voltage capable current) in the boost mode and to generate the buck voltage in the buck mode.