LED Driving Circuit With Dynamic Reference Voltage Control
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Solution Overview
Problem
Existing driving circuits for light emitting elements face inefficiencies in power consumption and temperature management, particularly in reducing voltage drop and preventing solder deterioration due to high temperatures.
Innovation Solution
A driving circuit that adjusts the reference voltage based on the driving current and incorporates a thermal shutdown circuit and terminal temperature detection to manage power consumption and prevent overheating, featuring a DC/DC converter, current sources, and a control circuit to optimize voltage and current delivery to light emitting units.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a fixed reference voltage is used in the driving circuit, then the circuit structure is simple, but the voltage drop at the current source increases leading to higher power consumption
Solution Approach 1:
The reference voltage is changed from a fixed value to a dynamically adjustable value that varies according to the driving current. The control circuit adjusts the reference voltage in real-time based on the actual driving current flowing through the light emitting element, thereby optimizing the operating point of the current source and reducing unnecessary voltage drop and power consumption.
Solution Approach 2:
The reference voltage parameter is made variable instead of fixed. By changing the reference voltage parameter according to the driving current, the system achieves better efficiency. The control circuit modifies the reference voltage level to match the actual operating conditions, reducing the voltage drop across the current source and minimizing power loss.
2Illumination intensity
If high driving current is supplied to achieve desired luminance, then the light output is sufficient, but the temperature increases causing solder deterioration
Solution Approach 1:
The control circuit implements feedback control by continuously monitoring the driving current and adjusting the reference voltage accordingly. This feedback mechanism allows the system to maintain the required luminance while optimizing the operating conditions to reduce excessive current and associated heat generation, thereby protecting the solder joints from thermal deterioration.
Solution Approach 2:
The system dynamically adjusts the reference voltage based on real-time operating conditions including temperature considerations. By making the reference voltage adjustable rather than fixed, the control circuit can optimize the driving current level to achieve the required luminance while minimizing heat generation that could lead to solder deterioration.
3Loss of energy
If the reference voltage is adjusted according to driving current to reduce power consumption, then energy efficiency improves, but the control circuit complexity increases
Solution Approach 1:
The control circuit automatically adjusts the reference voltage based on the actual driving current without requiring external intervention or complex control algorithms. The system serves itself by using the driving current information to directly control the reference voltage level, simplifying the overall control architecture while achieving energy efficiency improvements.
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 reduces power consumption by adjusting the reference voltage and prevents solder deterioration by monitoring and managing temperature, thereby enhancing the efficiency and longevity of light emitting elements.
Implementation Method 1
at least one light emitting units commonly connected to a first terminal supplied with a driving voltage
Implementation Method 2
DC/DC converter configured to supply a driving voltage to a first terminal to which at least one light emitting units are commonly connected
Data Source
AI summary
LED terminals are respectively provided to light emitting units, and are each connected to the second terminal of the corresponding one of the light emitting units. Current sources are respectively provided to the LED terminals, and are respectively configured to supply adjustable driving currents to the respective light emitting units via the respective LED terminals. A reference voltage source generates a reference voltage that corresponds to the driving current. A control circuit controls a DC/DC converter such that the lowest voltage from among voltages at the LED terminals matches the reference voltage.