LED Driving Circuit Voltage Boosting via Charge Pump
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Solution Overview
Problem
Conventional LED driving circuits face challenges with drive voltage shortages and power loss, especially when driving a large number of LEDs connected in series, which affects efficient current regulation and luminance homogeneity.
Innovation Solution
A circuit topology that includes a set of LEDs arranged in series with a power supply, a switching element, and a charge pump, controlled by a controller to switch between ON and OFF states, allowing for efficient voltage step-up and current regulation using inductor/transformer or capacitive multiplier configurations, thereby reducing power dissipation and improving efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If conventional LED driving circuits are used to drive a large number of LEDs connected in series, then the drive voltage requirement increases, but the available drive voltage becomes insufficient
Solution Approach 1:
The circuit segments the drive function into two parts: a main power supply providing base voltage and a charge pump circuit providing voltage boosting capability. This segmentation allows the system to handle high voltage requirements by combining multiple voltage sources rather than relying on a single power supply.
Solution Approach 2:
The charge pump circuit acts as an intermediary between the main power supply and the LED array. It receives power from the main supply and transforms it into the higher voltage needed to drive series-connected LEDs, mediating the voltage mismatch between available power and LED requirements.
2Reliability
If conventional LED driving circuits are used, then current regulation can be achieved, but power loss increases
Solution Approach 1:
The charge pump operates in periodic cycles, charging capacitors during off-periods and discharging them during on-periods. This periodic action allows energy to be stored and reused rather than continuously dissipated, reducing overall power loss while maintaining current regulation.
Solution Approach 2:
The circuit recovers energy that would otherwise be lost during switching transitions. The charge pump captures and stores energy in capacitors during non-critical periods and releases it when needed, effectively recovering energy rather than allowing it to be dissipated as heat.
3Power
If more components are added to improve voltage step-up capability, then drive voltage shortage is resolved, but device complexity increases
Solution Approach 1:
The charge pump circuit performs multiple functions: voltage step-up, energy storage, and power factor correction. By making this single circuit block multi-functional, the design avoids adding separate components for each function, thereby reducing overall complexity while achieving voltage step-up capability.
Solution Approach 2:
The patent combines the voltage boosting function with the existing power supply circuitry. Rather than adding a completely separate voltage multiplier stage, the charge pump is integrated with the main power supply, merging functions to reduce component count and simplify the overall circuit architecture.
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 solution enables efficient driving of LEDs with improved power consumption and luminance homogeneity, allowing for adjustable brightness and dimming capabilities with fewer components, and is not limited by the number of LEDs connected.
Implementation Method 1
a first charge pump coupled to the third node, wherein the first charge pump is charged by the power supply responsive to the switching element being in an ON state
Data Source
AI summary
Systems and methods for light emitting diodes (LEDs) circuits are provided. Aspects include a set of light emitting diodes (LEDs) arranged in series between a first node and a second node, a power supply coupled to the first node, a first switching element arranged in series between the first node and a third node, wherein the first switching element is in parallel with the set of LEDs, a first charge pump coupled to the third node, a controller configured to operate the first switching element by providing a control voltage for switching the first switching element between an ON and an OFF, wherein the control voltage comprises a switching frequency, and wherein the first charge pump is charged by the power supply responsive to the switching element being in an ON state.