Dual Supply Voltage Driver for LED Power Loss Reduction

Solution Overview

Problem

Existing solid state lighting systems face inefficiencies due to high voltage requirements in driving light emitting semiconductor devices, leading to power losses and increased component stress, as they rely on a single voltage supply that can result in excessive voltage across the driving means, causing heat loss and component strain.

Innovation Solution

The introduction of a second supply voltage, in addition to a first supply voltage, allows for reduced voltage across the driver circuit, enabling lower breakdown voltage ratings and more precise voltage adjustment across LEDs, thereby minimizing power losses and component stress by using a driver-integrated circuit with a switch mode converter and power converter configurations such as boost, buck, or capacitive converters.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If a single voltage supply is used to drive light emitting semiconductor devices, then the system structure is simple, but excessive voltage across the driving means causes power losses and component stress

Engineering Contradiction:

Improvepower lossesVSAvoidsystem structure

Core Design Contradiction:

Loss of energyVSDevice complexity

Solution Approach 1:

The voltage supply is segmented into two separate supplies: a first voltage supply connected to the anode of the LED string and a second voltage supply connected to the cathode. This segmentation allows each supply to operate at lower voltages, reducing the voltage burden on the driver circuit and minimizing power losses while maintaining the ability to drive high-voltage LED strings.

Inventive Principle:

Principle #1Segmentation

2Temperature

If a single voltage supply is used, then component count is reduced, but voltage across driver circuit increases causing heat loss and component strain

Engineering Contradiction:

Improveheat lossVSAvoidcomponent count

Core Design Contradiction:

TemperatureVSDevice complexity

Solution Approach 1:

The voltage supply is segmented into two separate supplies: a first voltage supply connected to the anode of the LED string and a second voltage supply connected to the cathode. This segmentation allows each supply to operate at lower voltages, reducing the voltage burden on the driver circuit and minimizing power losses while maintaining the ability to drive high-voltage LED strings.

Inventive Principle:

Principle #1Segmentation

3Productivity

If higher switching frequencies are used, then system efficiency improves, but component stress increases with single voltage supply

Engineering Contradiction:

Improvesystem efficiencyVSAvoidcomponent stress

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The voltage supply is segmented into two separate supplies: a first voltage supply connected to the anode of the LED string and a second voltage supply connected to the cathode. This segmentation allows each supply to operate at lower voltages, reducing the voltage burden on the driver circuit and minimizing power losses while maintaining the ability to drive high-voltage LED strings.

Inventive Principle:

Principle #1Segmentation

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 reduces power losses, lowers component stress, and allows for higher switching frequencies, enabling more efficient and cost-effective operation of solid state lighting systems by adjusting voltages to match LED requirements, thus improving overall system efficiency and reducing component costs.

Implementation Method 1

enabling more efficient and cost-effective operation of solid state lighting systems by adjusting voltages to match LED requirements

Methodology Applied

Scientific EffectSwitch mode conversion:

Implementation Method 2

driver-integrated circuit with a switch mode converter and power converter configurations such as boost, buck, or capacitive converters

Methodology Applied

Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 3

power converter configurations such as boost, buck, or capacitive converters

Methodology Applied

Scientific EffectCapacitance: Capacitance

Data Source

PatentEP2177081B1Solid state lighting system and a driver integrated circuit for driving light emitting semiconductor devices

Publication Date: 2019.06.12 NXP BV

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AI summary

The present invention relates to a solid state lighting system comprising at least one light emitting semiconductor device (LEDstr), at least one driving means (LEDdr) for driving a predetermined current through the at least one light emitting semiconductor device (LEDstr). The lighting system furthermore comprises a first voltage supplying unit (PSl) coupled to provide a first supply voltage (Vbusl) to a first side of the at least one light emitting semiconductor device, and a second voltage supplying unit (PS2) coupled to provide a second supply voltage (Vbus2) for the at least one light emitting semiconductor device. The first and the second supply voltages (Vbusl, Vbus2) are selected to optimize the voltage drop across the at least one light emitting semiconductor device (LEDstr).