External Termination Circuit for Display Signal Attenuation
Solution Overview
Problem
The attenuation of display interface signals in mobile apparatuses due to high impedance traces and internal termination impedance components in display driver integrated circuits (DDICs) leads to signal degradation, particularly when multiple DDICs are driven by a single signal producing circuit, increasing costs and reducing display capabilities.
Innovation Solution
A termination circuit is introduced that connects an impedance component between nodes of a cable, parallel to the series impedance of the trace and internal termination impedance components, reducing the overall impedance and attenuating effects on the display interface signal, and optionally includes switches and capacitors to adapt to different signal types.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If an impedance component is added in parallel to reduce overall impedance, then signal attenuation is reduced, but device complexity increases
Solution Approach 1:
A termination circuit is introduced as an intermediary component between the cable and the display driver integrated circuit. This termination circuit includes an impedance component connected in parallel to the series impedance formed by the trace and internal termination impedance, thereby reducing the overall impedance and minimizing signal attenuation without requiring fundamental changes to the existing DDIC architecture.
2Ease of operation
If internal termination impedance components are included in DDICs, then line termination function is provided, but signal attenuation increases
Solution Approach 1:
The invention merges the line termination function with an external termination circuit that includes a parallel impedance component. By combining the internal termination impedance component with the external parallel impedance, the overall impedance is reduced while maintaining the necessary line termination function, thereby improving signal strength without sacrificing termination capability.
3Adaptability or versatility
If multiple DDICs are driven by a single signal producing circuit, then display capabilities are enhanced, but signal attenuation increases due to increased load
Solution Approach 1:
The invention segments the termination function by providing individual termination circuits for each display driver integrated circuit. Each termination circuit includes its own parallel impedance component, allowing each DDIC to be properly terminated independently. This segmentation approach enables multiple DDICs to be driven by a single signal producing circuit while maintaining signal strength by preventing signal degradation at each individual connection point.
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
This configuration significantly reduces signal attenuation, especially for signals with small amplitude ranges, and allows for efficient transmission of both low and high-speed signals without the need for additional timing control circuits, thereby reducing costs and enhancing display capabilities.
Implementation Method 1
an impedance component connected between a first node and a second node, each of which is a node of a conductor of a cable. The first end of the cable can be configured to be connected to a signal producing circuit. A second end of the cable can be configured to be connected to a display driver integrated circuit
Data Source
AI summary
A termination circuit can include an impedance component. A first port can be configured to be connected to a first node. The first node can be a node of a conductor of a cable. A first end of the cable can be configured to be connected to a signal producing circuit. A second end of the cable can be configured to be connected to a first end of a trace disposed on a substrate of a display device. A second end of the trace can be connected to a display driver integrated circuit (DDIC). The DDIC can lack a termination impedance component internal to the DDIC to provide a line termination function for a serial interface with the signal producing circuit. A second port can be configured to be connected to a second node. The impedance component can be connected between the first port and the second port.