Display Driver Variable Current Source for Power Waste Reduction
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Solution Overview
Problem
Conventional display drivers face challenges in reducing power waste and heat generation, particularly as display panel size and resolution increase, leading to high power consumption and heat production due to the need for enhanced slew rate.
Innovation Solution
A display driver incorporating a variable current source controlled by a comparator based on the difference between input data values, which adjusts the current source to optimize power efficiency without increasing slew rate unnecessarily.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If the tail current of the output buffer is statically increased to enhance slew rate, then the drive ability is improved, but the power consumption greatly increases
Solution Approach 1:
The patent applies dynamics by transforming the static tail current into a dynamic, variable current that adapts to actual driving needs. The output buffer's tail current is controlled by a variable current source that responds to data change requirements, allowing the slew rate to be enhanced only when necessary rather than maintaining a constantly high current level.
Solution Approach 2:
The patent implements parameter changes by making the tail current parameter variable rather than fixed. The variable current source adjusts the current magnitude based on the difference between consecutive data values, changing the electrical parameter dynamically to match the actual driving demand and reduce unnecessary power consumption.
2Productivity
If the number of drive channel circuits is increased to handle larger display panels, then the drive ability is improved, but heat generation and power consumption increase
Solution Approach 1:
The patent applies dynamics by making the current consumption of each drive channel dynamic rather than static. Each output buffer adjusts its tail current based on actual data change requirements, allowing the system to handle large display panels with multiple channels while minimizing the heat generated by each individual channel when full drive capability is not needed.
3Speed
If the high driving signal is periodically generated to enhance slew rate, then the drive ability is improved, but the power consumption of the source driver increases
Solution Approach 1:
The patent applies periodic action by using the periodic comparison of consecutive data values to control the variable current source. The system periodically evaluates whether data changes require enhanced driving capability, and only activates the variable current when such changes are detected, thereby reducing energy waste compared to continuous high driving signals.
Solution Approach 2:
The patent implements feedback by using the comparator to continuously monitor the difference between consecutive data values and adjust the variable current source accordingly. This closed-loop control ensures that the tail current is enhanced only when the feedback indicates actual driving needs, eliminating redundant power consumption from unnecessary current increases.
Data Source
AI summary
A display driver and a driving method thereof is disclosed. The display driver includes at least one first latch, at least one second latch, an output buffer, and a comparator. The first latch receives input data. The input terminal of the second latch is coupled to the output terminal of the first latch. The output buffer, including at least one variable current source, is coupled to the second latch. The comparator is coupled to the first latch, the second latch, and the variable current source. The comparator generates at least one control signal of the variable current source.