Hysteresis Comparator LED Driver Circuit Cost Reduction
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Solution Overview
Problem
Existing LED driver circuits, particularly those using dedicated integrated circuits, are expensive, making LED lighting less competitive compared to other lighting solutions despite offering good precision.
Innovation Solution
A cost-effective LED driver circuit utilizing a switched-mode power supply with a hysteresis-configured comparator circuit, controlled by a voltage reference and employing standard components, allowing for accurate PWM control and noise reduction through a shunt resistor and low-pass filter, enabling efficient regulation of LED current.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If dedicated LED driver integrated circuits are used, then LED current regulation precision is improved, but manufacturing cost increases
Solution Approach 1:
The patent divides the LED driver system into separate functional modules: a switched-mode power supply unit for voltage conversion and a comparator circuit for current regulation. This segmentation allows each module to be optimized independently and manufactured using standard components rather than requiring a single expensive integrated circuit, thereby reducing manufacturing cost while maintaining regulation precision.
Solution Approach 2:
The comparator circuit is designed to work with standard off-the-shelf components that can be used across multiple LED driver applications. The voltage reference and hysteresis configuration provide universal functionality that can regulate LED current accurately without requiring application-specific integrated circuits, thus reducing cost while preserving precision.
2Ease of manufacture
If simple standard components are used, then manufacturing cost decreases, but LED current regulation precision deteriorates
Solution Approach 1:
The patent implements a feedback mechanism using a comparator that continuously monitors the LED current through a sensing resistor and adjusts the switched-mode power supply output accordingly. This feedback loop, combined with hysteresis configuration, ensures precise current regulation even when using simple standard components, thereby maintaining high precision while reducing manufacturing cost.
Solution Approach 2:
The patent uses parameter changes in the comparator circuit, specifically implementing hysteresis by configuring the comparator with positive feedback through resistors. This changes the switching characteristics of the power supply to provide stable and precise current regulation. By adjusting circuit parameters rather than requiring precision integrated circuits, the design achieves accurate regulation with low-cost standard components.
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 provides a low-cost, accurate LED driver circuit capable of producing precise light control, suitable for multiple LED configurations, by reusing voltage references and minimizing component requirements, thus reducing overall costs and enhancing competitiveness.
Implementation Method 1
a hysteresis-configured comparator circuit in order to regulate the LED current, and the switching levels of the comparator being set by a voltage reference
Implementation Method 2
This corresponding voltage may be fed to the comparator circuit via a low-pass filter. This avoids the feedback arrangement being affected by switching noise.
Implementation Method 3
A shunt resistor may receive a LED current in order to establish a corresponding voltage, which is fed to the comparator circuit.
Implementation Method 4
a switched-mode power supply (smps) having down-converting characteristics, connected between the supply input terminal and the first output terminal
Data Source
AI summary
The present invention relates to a low cost LED driver module comprising a switched-mode power supply (smps) having down-converting characteristics (11) which is controlled by a comparator (31). The comparator is hysteresis configured, which reduces ripple and transients in the LED current, and the module can be accomplished with inexpensive standard components.