Current Integrator Charge Transfer for High Dynamic Range
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current electric current integrators face challenges in achieving a high readout dynamic range while maintaining system sensitivity, particularly in detecting scenes with large temperature differences, and are prone to noise due to multiple switchings of the integration capacitor.
Innovation Solution
A charge transfer circuit is used to modify the output voltage of the integration capacitor by transferring charges into it when the output voltage reaches a reference value, extending the readout dynamic range without compromising sensitivity and reducing noise.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the integration capacitor is reversed multiple times to extend dynamic range, then the readout dynamic range is improved, but noise increases due to multiple switchings
Solution Approach 1:
The patent applies preliminary action by pre-charging the capacitor to a reference voltage level before integration begins. This initial conditioning of the capacitor state allows the integration process to start from a known reference point, enabling dynamic range extension without requiring multiple reversal operations during integration, thereby reducing noise from switchings.
2Adaptability or versatility
If the integration capacitor is reversed to extend dynamic range, then the readout dynamic range is improved, but system sensitivity deteriorates
Solution Approach 1:
The patent introduces a reference voltage as an intermediary element. By comparing the integration output against this stable reference voltage and using it to control the switching timing, the system can extend dynamic range while maintaining sensitivity. The reference voltage acts as a mediator that allows dynamic range adjustment without directly interfering with the integration process or degrading signal detection capability.
3Adaptability or versatility
If the integration capacitor is reversed multiple times, then the readout dynamic range is extended, but the CTIA behavior is degraded
Solution Approach 1:
The patent applies preliminary action by pre-charging the capacitor to a reference voltage level before integration begins. This initial conditioning of the capacitor state allows the integration process to start from a known reference point, enabling dynamic range extension without requiring multiple reversal operations during integration, thereby reducing noise from switchings.
Solution Approach 2:
The patent implements feedback by continuously monitoring the output voltage and using it to control the switching timing. The output voltage feedback signal determines when the capacitor should be switched between different states, ensuring that switching operations occur at optimal moments that maintain CTIA linearity and reliability while extending the usable dynamic range.
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 approach allows for an extended dynamic range in electric current integration with reduced noise, maintaining high sensitivity and linearity of the signal, and is suitable for detecting scenes with large temperature variations without degrading the CTIA's behavior.
Implementation Method 1
an integration capacitor connected between said first input and said output of said operational amplifier; said output delivering an output voltage which varies according to the variation of the quantities of charges in said integration capacitor
Implementation Method 2
a charge transfer circuit, configured to be connected on said integration node and to transfer charges into said integration capacitor when the comparison circuit detects that said output voltage is substantially equal to said reference voltage
Data Source
AI summary
A device of integration of an electric current received on an integration node, includes an operational amplifier, an integration capacitor, and a circuit for modifying an output voltage of the operational amplifier formed by a charge transfer circuit configured to be connected on the integration node and to transfer charges into the integration capacitor. The device also includes a comparison circuit configured to trigger the modification circuit at least once during the integration duration, and a storage circuit configured to store the number of triggerings which have occurred during the integration duration. The received electric current is calculated according to the output voltage as well as to the number of triggerings multiplied by the modification of the output voltage induced by the modification circuit.