LED Driver Offset Compensation Low Resistance Current Sensing
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Solution Overview
Problem
Existing LED drivers face challenges in maintaining stable current control through LED channels due to power inefficiency caused by detection resistors, which consume power and generate heat, and low detection voltage levels that can lead to offset issues and difficulty in controlling LED brightness.
Innovation Solution
A light emitting diode (LED) driver that includes a power supplying unit, a driving unit with an amplification unit, an operational amplifier, and an offset compensation unit to amplify detection voltage, compensate for voltage offsets, and adjust current flow to maintain constant brightness, using a low power consumption resistor and integrated circuit design.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a detection resistor with high resistance value is used to detect current, then current detection accuracy is improved, but power consumption increases and heat is generated
Solution Approach 1:
The patent changes the resistance value parameter of the detection resistor to a low resistance value (e.g., 0.1 ohm to 1 ohm) to reduce power consumption and heat generation. This parameter change is compensated by adjusting the gain of the amplification unit to maintain detection accuracy despite the lower resistance value.
2Use of energy by moving object
If a detection resistor with low resistance value is used to reduce power consumption, then power efficiency is improved, but detection voltage level becomes too low causing offset issues
Solution Approach 1:
The patent introduces an amplification unit as an intermediary component between the detection resistor and the control circuit. This amplification unit boosts the low detection voltage signal to an appropriate level, enabling the use of low resistance detection resistors without suffering from insufficient detection voltage.
Solution Approach 2:
The patent changes the gain parameter of the amplification unit to compensate for the low detection voltage. By adjusting the gain to a predetermined value, the amplified detection voltage reaches an appropriate level for stable LED current control while maintaining low power consumption.
3Stability of the object's composition
If a detection resistor is used to maintain constant current, then LED brightness stability is improved, but power consumption increases due to heat generation
Solution Approach 1:
The patent changes the resistance value parameter to a low value to minimize power loss and heat generation. The stability of LED brightness is maintained through the combination of low resistance detection and high-gain amplification, which together provide accurate current sensing without excessive power dissipation.
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 improves power efficiency by using low power consumption resistors and compensates for voltage offsets, enabling stable and constant LED brightness control, thereby enhancing the performance of LED drivers.
Implementation Method 1
a driving unit amplifying a detection voltage detected based on a current from the LED channel by a predetermined gain
Implementation Method 2
a detection resistor used for detecting current flowing through the LED channel so as to obtain the detection voltage
Implementation Method 3
a power supplying unit converting an input voltage into a predetermined driving voltage so as to supply the driving voltage to an LED channel
Data Source
AI summary
There is provided a light emitting diode driver capable of improving power efficiency by using a resistor having a low power consumption rating while controlling an LED channel so that it has constant brightness stably. The light emitting diode driver includes: a power supplying unit converting an input voltage into a predetermined driving voltage so as to supply the driving voltage to an LED channel; and a driving unit amplifying a detection voltage detected based on a current from the LED channel by a predetermined gain and controlling the current flowing through the LED channel so that the amplified detection voltage has a level equal to that of a predetermined reference voltage.