Non-uniform Counter Widths for Image Sensor Memory Voltage
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
As image sensor resolution and frame rates increase, data transfer rates rise, leading to higher power dissipation in memory cells, causing a voltage drop that can hinder the operation of centrally located memory cells, especially at higher frequencies, due to the serial arrangement of memory cells under a common supply voltage.
Innovation Solution
The design involves memory cells with non-uniform dimensions, where peripherally located cells have smaller dimensions to reduce power dissipation and centrally located cells have larger dimensions to maintain a sufficient voltage differential, optimizing voltage delivery and reducing voltage drop across the memory bank.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If data transfer rate is increased by increasing operating frequency of memory cells, then productivity is improved, but power dissipation increases causing voltage drop that deteriorates reliability
Solution Approach 1:
The patent applies local quality by varying the counter width according to the spatial position of memory cells within the memory bank. Specifically, memory cells located at different positions (e.g., corners vs. center) are assigned different counter widths to compensate for the non-uniform voltage distribution caused by IR drop. This ensures that each memory cell receives an appropriate voltage differential for reliable operation at high frequencies, resolving the contradiction between productivity and reliability.
2Speed
If counter width is increased to improve operating frequency, then speed is improved, but power dissipation increases causing greater voltage drop
Solution Approach 1:
The patent implements local quality by assigning different counter widths to memory cells based on their specific location within the memory bank. Memory cells that require higher operating frequencies are given wider counters, while cells in positions with better voltage supply receive standard or narrower counters. This localized optimization achieves the necessary speed performance without uniformly increasing power dissipation across the entire memory bank.
Solution Approach 2:
The patent applies parameter changes by dynamically adjusting the counter width parameter according to the spatial coordinates of each memory cell. The counter width is modified as a function of position within the memory bank, allowing the system to optimize operating frequency and power dissipation characteristics for each specific location, thereby resolving the contradiction between speed and energy loss.
3Device complexity
If uniform counter dimensions are used across all memory cells, then device complexity is reduced, but performance becomes non-uniform due to voltage drop variations
Solution Approach 1:
The patent resolves this contradiction by applying local quality - using non-uniform counter dimensions that are specifically tailored to the voltage characteristics of each memory cell location. This approach increases device complexity slightly but dramatically improves operational consistency, ensuring that all memory cells regardless of position can operate reliably at the required frequency.
Solution Approach 2:
The patent employs asymmetry by deliberately designing counters with different widths at different locations within the memory bank. This asymmetric design compensates for the symmetric voltage drop pattern that occurs in uniform memory arrays, creating a non-uniform counter width distribution that balances the performance across all memory cells and ensures operational consistency.
Data Source
AI summary
Counters with various widths for an image sensor. An image sensor includes a plurality of image pixels arranged in rows and columns of a pixel array. A plurality of memory cells are individually coupled to corresponding columns of the pixel array. The memory cells are arranged in a memory bank. The memory bank includes a first memory cell coupled to a first column of the pixel array. The first memory cell includes a first counter having a first width. A second memory cell is coupled to a second column of the pixel array. The second memory cell comprises a second counter having a second width. The first width and the second width are different.