Image Sensor Data Transmission Circuit Split Bus Segments
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional CMOS image sensors face challenges in data transmission due to RC time constant characteristics of transmission lines, which affect signal quality and require careful determination of line length and area, limiting efficient data transfer in portable electronic devices.
Innovation Solution
The implementation of a data transmission circuit with multiple bus segments and data regeneration circuits, where each data regeneration circuit can operate as a buffer, logic gate, or synchronous circuit, synchronizing data and address transmission timing to enhance data transfer efficiency across the bus segments.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single transmission line is used to transmit pixel signals, then the structure is simple, but the RC time constant increases with line length, degrading signal quality and limiting transmission distance
Solution Approach 1:
The transmission line is divided into multiple bus segments (first bus segment, second bus segment, third bus segment, etc.) with data regeneration circuits positioned between them. This segmentation reduces the effective length of each transmission segment, thereby reducing the RC time constant of each segment while maintaining overall transmission capability and signal quality across the entire data transmission path.
2Quantity of substance
If the transmission line length is increased to accommodate more pixels, then more pixels can be covered, but the RC time constant increases, affecting signal integrity
Solution Approach 1:
By dividing the transmission path into multiple bus segments with regeneration circuits, the system can cover a larger number of pixels without sacrificing signal integrity. Each segment maintains acceptable signal quality through reduced RC time constant, while the regeneration circuits restore signals between segments, enabling extended coverage.
Solution Approach 2:
Data regeneration circuits are introduced as intermediary elements between bus segments. These regeneration circuits actively restore and retransmit signals, acting as mediators that maintain signal integrity across extended transmission distances, thereby enabling the system to cover more pixels while preserving signal quality.
3Reliability
If data regeneration circuits are added between bus segments, then signal quality is maintained over longer distances, but the device complexity increases
Solution Approach 1:
The transmission system is segmented into manageable bus segments with regeneration circuits positioned between them. This segmentation approach maintains signal quality by limiting each segment's RC time constant while distributing the complexity of regeneration circuits across multiple locations, making the overall system more manageable and modular.
4Productivity
If synchronous circuits are used for data regeneration, then data transmission timing is synchronized and efficient, but the circuit complexity increases
Solution Approach 1:
Synchronous circuits operate based on periodic clock signals, regenerating data at regular intervals synchronized with the pixel readout timing. This periodic operation ensures that data is regenerated and transmitted in sync with the imaging sequence, improving transmission efficiency and timing accuracy while using standard synchronous circuit design techniques.
Data Source
AI summary
A data transmission circuit of an image sensor includes first to Kth bus segments, and first to Kth data regeneration circuits respectively connected to the first to Kth bus segments and the first to (K−1)th data regeneration circuits respectively connected to the second to Kth bus segments. Each of the first to Kth data regeneration circuits may be embodied as one of a buffer, a logic gate, and a synchronous circuit operating in response to a clock signal.