LED Backlight Driving Circuit Dynamic Frequency Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional LED backlight driving circuits have a fixed driving frequency, which leads to increased power consumption and reduced efficiency when the working current of the LED string is decreased, as the power consumption of components like the inductor, rectifier diode, and FETs is proportional to the driving frequency.
Innovation Solution
A LED backlight driving circuit that includes a current detection module, a control signal module, and a frequency regulation module, which detects the working current of the LED string and adjusts the driving frequency by selectively switching circuit loops with different resistances to communicate with the driver chip, allowing for dynamic frequency adjustment based on the working current.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If the driving frequency is fixed, then the circuit design is simple, but the power consumption increases and driving efficiency decreases when the working current is decreased
Solution Approach 1:
The patent applies the dynamics principle by making the driving frequency adjustable rather than fixed. The frequency regulation module dynamically changes the driving frequency based on the working current magnitude, allowing the system to adapt to different operating conditions and reduce power consumption when working current is decreased.
Solution Approach 2:
The patent changes the parameter of driving frequency based on the working current magnitude. When the working current is decreased, the driving frequency is correspondingly decreased, which reduces the power consumption of components like the inductor, rectifier diode, and FETs while maintaining optimal driving efficiency.
2Loss of energy
If the driving frequency is decreased to reduce power consumption, then the power consumption decreases, but the driving efficiency may be compromised if the frequency is not adjusted appropriately
Solution Approach 1:
The patent implements feedback through the current detection module that continuously monitors the working current and provides detection signals to the control signal module. This feedback mechanism ensures that the driving frequency is adjusted appropriately based on the actual working current, maintaining optimal driving efficiency while reducing power consumption.
Solution Approach 2:
The system dynamically adjusts the driving frequency based on real-time working current conditions. The frequency regulation module ensures that the driving frequency is decreased correspondingly when the working current is decreased, maintaining the balance between power consumption and driving efficiency across different operating conditions.
3Power
If the duty ratio of the second square wave signal is decreased to reduce working current, then the working current decreases, but the driving frequency should be decreased correspondingly which is not possible in a fixed frequency circuit
Solution Approach 1:
The patent makes the driving frequency dynamic by introducing the frequency regulation module that adjusts the driving frequency based on the working current magnitude. This allows the system to adapt to different operating conditions, enabling the driving frequency to be decreased when the working current is decreased, which would not be possible in a fixed frequency circuit.
Solution Approach 2:
The system changes the driving frequency parameter based on the working current magnitude. When the duty ratio of the second square wave signal is decreased to reduce working current, the driving frequency is correspondingly decreased through the frequency regulation module, providing the adaptability needed to optimize performance across different operating conditions.
Data Source
AI summary
A LED backlight driving circuit includes a voltage boosting circuit for converting an input voltage into an output voltage for a LED string; a current control module connected to a negative terminal of the LED string and for regulating a working current of the LED string; a driver chip for supplying the voltage boost circuit and current control module respectively with first and second square wave signals; a current detection module for detecting the working current of the LED string to generate detection signal; a control signal module for receiving the detection signal to generate a control signal; and a frequency regulation module for receiving the control signal to thereby generate a resistance. The frequency regulation module connects the driver chip, and the driver chip regulates a driving frequency of the driving circuit according to the resistance. A LCD device using the driving circuit also is provided.