Shared Capacitor Readout Circuit for Low-Power Image Sensors
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Image sensors face challenges in reducing area and power consumption, leading to significant overhead in terms of the number of readout circuits required, which affects both space and energy efficiency.
Innovation Solution
A readout circuit design that incorporates a plurality of capacitors and a switch circuit to store and output signals from multiple pixel circuits, allowing for shared readout circuits across rows or columns, thereby reducing the number of readout circuits needed and minimizing additional area and power consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If multiple readout circuits are used for each pixel circuit, then signal reading capability is improved, but area consumption increases
Solution Approach 1:
Multiple pixel circuits share a common readout circuit by combining their signal paths through capacitive coupling. The readout circuit processes signals from multiple pixels sequentially or simultaneously, reducing the total number of readout circuits needed while maintaining full reading capability for all pixel circuits.
Solution Approach 2:
The readout circuit is designed to handle signals from multiple pixel circuits through a universal interface. By using capacitors to store and transfer signals, a single readout circuit can serve multiple pixels, making the readout circuit multi-functional and reducing overall area consumption.
2Productivity
If multiple readout circuits are used for each pixel circuit, then signal reading capability is improved, but power consumption increases
Solution Approach 1:
Multiple pixel circuits share a common readout circuit, reducing the total number of active components that consume power. By combining signal paths and using capacitive coupling, the system achieves full reading capability with fewer power-hungry readout circuits.
Solution Approach 2:
The signal from pixel circuits is copied and stored in capacitors before being transferred to the readout circuit. This allows the readout circuit to process signals without requiring continuous high-power operation, as signals are held in capacitive storage elements until ready for reading.
3Quantity of substance
If capacitors are added to the readout circuit, then signal storage capability is improved, but circuit area increases
Solution Approach 1:
Capacitors are implemented using thin-film or planar structures that minimize area consumption. The capacitive elements are designed as compact storage regions within the pixel circuit, using thin dielectric layers and optimized electrode geometries to achieve maximum storage capability with minimum area overhead.
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 design effectively reduces the area and power consumption of image sensors by allowing multiple pixel circuits to share a single readout circuit, achieving a reduction to 1/S of the original values without increasing the circuit's size or significantly altering power usage.
Implementation Method 1
a plurality of capacitors are connected to the output circuit through the switch circuit; the plurality of capacitors are configured to store output signals of a plurality of pixel circuits, respectively
Data Source
AI summary
A readout circuit, an image sensor and an electronic device are provided, which could effectively reduce an area and power consumption of the image sensor. The readout circuit includes a plurality of capacitors, a switch circuit and an output circuit; where the plurality of capacitors are connected to the output circuit through the switch circuit; the plurality of capacitors are configured to store output signals of a plurality of pixel circuits, respectively; and the output circuit is configured to output signals stored by the plurality of capacitors through the switch circuit one-by-one.