Imaging Pixel ADC Circuit with Segmented Power Amplification
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current imaging devices face challenges in achieving high image quality due to limitations in analog-to-digital conversion processes, particularly in comparing pixel signals with reference signals effectively, which affects the accuracy and reliability of captured images.
Innovation Solution
The proposed imaging device incorporates a light-receiving pixel, a reference signal generator, and multiple amplification sections with specific transistor and switch configurations to perform comparison operations based on pixel and reference signals, utilizing distinct power supply nodes to enhance signal processing and output, thereby improving image data conversion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a single power supply is used for all amplification sections, then the device complexity is reduced, but power supply noise and voltage fluctuations affect signal processing accuracy
Solution Approach 1:
The power supply system is segmented into multiple independent power supply circuits, each providing power to specific amplification sections. This segmentation isolates power supply noise and voltage fluctuations to individual sections, preventing them from affecting the entire signal processing chain, thereby improving signal processing accuracy while maintaining manageable device complexity through modular power supply design.
2Measurement precision
If multiple amplification sections with different power supplies are used, then signal processing accuracy is improved, but the device complexity increases
Solution Approach 1:
The signal processing chain is divided into multiple amplification sections (first, second, third amplification sections) with distinct power supplies. Each section handles specific signal processing tasks with optimized power characteristics, improving image data conversion accuracy by isolating noise sources while maintaining clear functional boundaries that manage overall device complexity.
Solution Approach 2:
Different amplification sections are provided with different power supply characteristics tailored to their specific functions. The first amplification section uses a first power supply optimized for its signal range, while subsequent sections use different power supplies suited to their respective signal processing requirements, achieving local optimization of signal processing accuracy without requiring a uniformly complex system architecture.
3Ease of manufacture
If power supply voltages are shared across all sections, then the device is easier to manufacture, but noise and fluctuations degrade image quality
Solution Approach 1:
The power supply system is segmented into multiple independent circuits that can be implemented using standard manufacturing processes for multi-power supply integrated circuits. While this increases manufacturing complexity compared to single power supply designs, the segmentation prevents noise and voltage fluctuations from propagating across the entire system, thereby protecting image quality and providing better overall reliability that justifies the enhanced manufacturing requirements.
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 enhances the image quality by accurately converting pixel signals into digital data, reducing noise and fluctuations in power supply voltages, leading to improved image capture and processing accuracy.
Implementation Method 1
a pixel generates a pixel signal corresponding to the amount of received light
Data Source
AI summary
An imaging device according to the present disclosure includes a light-receiving pixel; a reference signal generator; a first amplification section; a second amplification section; a third amplification section; and a counter. The first amplification section is coupled to a first power supply node and a second power supply node. The first amplification section performs a comparison operation on the basis of a pixel signal and a reference signal. The first amplification section outputs a signal corresponding to a result of the comparison to a first node. The second amplification section includes a first transistor and a first load circuit. The first transistor includes a gate coupled to the first node, a drain coupled to a second node, and a source coupled to the second power supply node. The third amplification section includes a second transistor and a first switch. The second transistor includes a gate coupled to the second node, a source coupled to the first power supply node, and a drain coupled to a third node. The first switch applies a predetermined voltage to the third node by being turned on. The counter is coupled to a third power supply node and a fourth power supply node. The counter stops a count operation on the basis of a voltage of the third node.