LED Driver Circuit Using Charge Pump and Linear Regulator

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Solution Overview

Problem

Existing LED driver circuits for multiple LED strings are complex and inefficient due to the need for multiple power converters and high power dissipation by linear regulators, which increases energy loss and reduces power efficiency.

Innovation Solution

A circuit configuration that includes a power converter, one or more charge pumps, and a linear regulator to generate output signals for multiple LED strings, eliminating the need for additional power converters and minimizing power dissipation by the linear regulator, thereby reducing complexity and energy loss.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If multiple power converters are used to drive multiple LED strings, then each LED string can be independently controlled, but the circuit complexity increases

Engineering Contradiction:

Improveindependent LED string controlVSAvoidcircuit complexity

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent combines multiple power conversion functions into a single integrated circuit that can drive multiple LED strings. The circuit uses one power converter core with multiple output channels, each capable of independent LED string control. This merging approach maintains the adaptability of controlling multiple LED strings independently while significantly reducing the overall circuit complexity compared to using separate power converters for each string.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The power converter circuit is designed with multi-functionality to serve multiple LED strings through a single device. The circuit can operate in different modes (buck, boost, buck-boost) and can independently regulate current to multiple LED strings simultaneously. This universal design allows one power converter to perform the functions that would otherwise require multiple separate converters, reducing complexity while maintaining control versatility.

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Reliability

If a linear regulator is used to regulate voltage for LED strings, then voltage control is achieved, but power dissipation increases

Engineering Contradiction:

Improvevoltage controlVSAvoidpower dissipation

Core Design Contradiction:

ReliabilityVSLoss of energy

Solution Approach 1:

The patent replaces the traditional linear regulator (which dissipates excess power as heat) with a switching power converter architecture. The switching converter uses energy storage elements (inductors and capacitors) to transfer and regulate power efficiently, converting excess voltage into useful current rather than dissipating it as heat. This substitution maintains reliable voltage and current control for LED strings while dramatically reducing power dissipation and improving overall efficiency.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Adaptability or versatility

If additional power converters are added to support multiple lighting modes, then more lighting modes are available, but the circuit complexity increases

Engineering Contradiction:

Improvelighting modesVSAvoidcircuit complexity

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent implements a dynamic power converter that can switch between different operating modes (buck mode for high voltage input, boost mode for low voltage input, buck-boost for intermediate voltages) to support multiple lighting modes. The circuit uses control logic to dynamically adjust its operation based on input voltage conditions and desired output requirements. This dynamic capability allows the single power converter to provide multiple lighting modes without requiring separate dedicated converters for each mode, thereby maintaining versatility while minimizing complexity.

Inventive Principle:

Principle #15Dynamics

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

The proposed circuit design achieves efficient power delivery to multiple LED strings with reduced complexity and energy loss, enhancing power efficiency and simplifying the circuit architecture.

Implementation Method 1

a power converter unit configured to receive an input signal from a power source and generate a first output signal including a first voltage

Methodology Applied

Scientific EffectPower conversion:

Implementation Method 2

a charge pump configured to receive at least a portion of the first output signal from the power converter unit and generate a second output signal including a second voltage

Methodology Applied

Scientific EffectCharge pumping:

Implementation Method 3

a linear regulator configured to receive the second output signal from the charge pump and generate a third output signal including a third voltage

Methodology Applied

Scientific EffectLinear regulation:

Data Source

PatentUS10624165B1Circuit for providing power to two or more strings of LEDs

Publication Date: 2020.04.14 INFINEON TECHNOLOGIES AG

AI summary

This disclosure includes systems, methods, and techniques for controlling delivery of power to one or more strings of light-emitting diodes (LEDs). For example, a circuit includes a power converter unit configured to receive an input signal from a power source and generate a first output signal comprising a first voltage, a charge pump configured to receive at least a portion of the first output signal from the power converter unit and generate a second output signal comprising a second voltage, and a linear regulator configured to receive the second output signal from the charge pump and generate a third output signal comprising a third voltage.