Feedback Amplifier Reset Circuit for Accurate Multichannel Reset
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Solution Overview
Problem
Existing reset mechanisms in feedback amplifier circuits, particularly in multichannel configurations, lead to unpredictable and inaccurate reset behavior due to deviations in bias voltages when multiple integrators reset simultaneously, affecting the accuracy of the reset operation.
Innovation Solution
A method involving a control circuit that manages the connection and disconnection of feedback and reset capacitors across reference voltages using specific switch control signals, allowing for predictable and accurate resetting of feedback capacitors without altering the bias voltages, ensuring consistent reset voltage differences across multiple integrators.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If multiple integrators share common bias voltages and reset simultaneously, then reset operation can be performed, but the bias voltages deviate from their values causing unpredictable and inaccurate reset behavior
Solution Approach 1:
The patent divides the reset operation into two distinct phases: first connecting reset capacitors to bias voltages to charge them, then disconnecting and connecting them to feedback capacitors to transfer charge. This segmentation prevents simultaneous drawing of current from bias voltages by multiple integrators, eliminating voltage deviations and ensuring accurate reset operations in multichannel configurations.
Solution Approach 2:
The reset capacitors are pre-charged to the bias voltages before being connected to the feedback capacitors. This preliminary charging action ensures that when the reset operation occurs, the capacitors have the correct voltage levels already established, preventing any deviation in bias voltages during the actual reset transfer.
2Ease of operation
If feedback capacitors are reset by connecting them directly to bias voltages, then reset can be achieved, but the total capacitance across bias voltages becomes unpredictable when multiple integrators reset simultaneously
Solution Approach 1:
The patent introduces reset capacitors as intermediary elements between the bias voltages and the feedback capacitors. These reset capacitors are first charged to the bias voltages, then disconnected and connected to the feedback capacitors to transfer charge. This intermediary approach ensures that the total capacitance drawn from bias voltages is always predictable (only the reset capacitors), regardless of how many integrators are resetting simultaneously.
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 ensures accurate and predictable resetting of feedback capacitors, maintaining the stability of the amplifier's operating regime and preventing non-linear behavior, even in multichannel configurations, by managing the reset process through controlled switch operations.
Implementation Method 1
a reset capacitor CR selectively connected between first and second voltages V1, V2, to reset a voltage across the feedback capacitor CF
Data Source
AI summary
An amplifier system can include a feedback amplifier circuit having an amplifier, a feedback capacitor connected between an input terminal and an output terminal of the amplifier by at least one first switch, and a reset capacitor connected across the feedback capacitor by at least one second switch and between a pair of reference voltages by at least one third switch. During an input-signal processing phase of operation, a control circuit may close the at least one first switch and open the at least one second switch to electrically connect the feedback capacitor between the input and output terminals to engage feedback processing by the feedback amplifier circuit, and close the third switch to electrically connect the reset capacitor between the first and second voltages to charge the reset capacitor to a selectable voltage difference. During a reset phase of operation, the control circuit may open the at least one third switch, close the at least one second switch and open the at least one first switch to electrically connect the reset capacitor across the feedback capacitor to reset the feedback capacitor using the reset capacitor. The amplifier system can optionally include a plurality of the feedback amplifier circuits.