Display Device Slew Rate Control for EMI Noise Reduction
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Solution Overview
Problem
Display devices face challenges in reducing electromagnetic interference (EMI) noise due to high-rate MUX clock signals, which affect the miniaturization and high-resolution requirements of these devices.
Innovation Solution
A display panel and driving method that incorporate a timing controller with slew rate control units to manage the slew rate of MUX clock signals, using complementary positive and negative MUX clock signals and transmission gates to control the slew rates in both rising and falling sections, ensuring that intersection points occur at the same voltage, thereby reducing EMI noise.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If a MUX circuit is used to reduce the number of data lines, then the number of data lines is reduced, but EMI noise increases due to high-rate MUX clock signals
Solution Approach 1:
The patent applies parameter changes by adjusting the slew rate of the MUX clock signal. The slew rate control unit modifies the rising and falling edge characteristics of the clock signal to reduce high-frequency components that generate EMI noise. This allows the MUX circuit to operate with controlled edge transitions that minimize electromagnetic interference while maintaining the data line reduction benefit
Solution Approach 2:
The patent converts the potentially harmful high-frequency components of the MUX clock signal into a beneficial controlled transition. By deliberately shaping the clock signal edges through slew rate control, the harmful EMI-generating rapid transitions are transformed into controlled, slower transitions that reduce noise while still enabling the MUX function to reduce data line count
2Speed
If the slew rate of MUX clock signal is increased to improve switching speed, then switching speed improves, but EMI noise increases
Solution Approach 1:
The patent uses parameter changes by independently controlling the rising slew rate and falling slew rate of the MUX clock signal. The slew rate control unit adjusts these parameters to optimize the balance between switching speed and EMI noise generation, allowing different slew rates for rising and falling edges to achieve both fast switching and noise reduction
3Manufacturing precision
If the display device is miniaturized with high resolution, then resolution improves, but EMI noise management becomes more difficult
Solution Approach 1:
The patent applies parameter changes to the clock signal characteristics to accommodate miniaturized high-resolution display requirements. By controlling the slew rate parameters of the MUX clock signal, the system can achieve the fast switching needed for high-resolution displays while managing EMI noise through optimized edge transition rates
Data Source
AI summary
Provided are a display device and a driving method thereof. The display device includes a display panel including a plurality of pixels defined by allowing a plurality of gate lines and a plurality of data lines to intersect each other; a timing controller generating a gate control signal, a data control signal, a MUX clock signal, and image data; a gate driving circuit sequentially providing gate signals to the plurality of gate lines based on the gate control signal; a data driving circuit supplying a data signal to the plurality of data lines based on the image data and the data control signal to drive the pixels; and a MUX circuit receiving the data signal and outputting the data signal in a time division manner to the data lines according to the MUX clock signal. The timing controller includes a slew rate control unit controlling a slew rate of the MUX clock signal.