Differential-to-Single-Ended Converter With Noise-Balanced Feedback
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional differential to single-ended converters face issues with common-mode feedback circuit noises and large voltage swings at input terminals, which degrade the linearity of output signals.
Innovation Solution
A differential to single-ended converter design featuring a feedback circuit that generates a first feedback signal to reduce voltage swing at the operational amplifier's positive terminal and a second feedback signal to balance noises at both terminals, using resistors and a buffer to control noise and maintain linearity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a differential operational amplifier is used to implement the differential to single-ended converter, then the converter can process differential input signals, but common-mode feedback circuit noises are introduced
Solution Approach 1:
The feedback circuit is segmented into two independent feedback paths: a first feedback path connecting the output to the positive input terminal, and a second feedback path connecting the output to the negative input terminal. This segmentation allows independent optimization of each feedback path to address different problems - the first path reduces voltage swing while the second path balances noise, thereby resolving the contradiction between differential signal processing and noise introduction.
2Device complexity
If a single-ended operational amplifier is used to implement the differential to single-ended converter, then the circuit structure is simplified, but large voltage swing at the input terminal degrades linearity
Solution Approach 1:
A feedback mechanism is introduced where a first feedback signal is generated from the output signal and fed back to the positive input terminal of the operational amplifier. This feedback signal is designed to reduce the voltage swing at the input terminal, thereby improving linearity while maintaining the simplified single-ended operational amplifier structure.
3Manufacturing precision
If feedback circuit is added to reduce voltage swing at operational amplifier terminals, then linearity is improved, but noise from the feedback circuit may affect the output signal
Solution Approach 1:
The feedback circuit employs asymmetric feedback paths with different configurations: the first feedback path connects to the positive input terminal to reduce voltage swing, while the second feedback path connects to the negative input terminal specifically to balance noise. This asymmetric design allows each feedback path to address different aspects of the problem, improving linearity while managing noise.
Data Source
AI summary
The present invention provides a differential to single-ended converter including a first input node, a second input node, an operational amplifier and a feedback circuit. The operational amplifier has a first terminal and a second terminal, wherein the first terminal of the operational amplifier receives a first signal from the first input terminal, and the second terminal of the operational amplifier receives a second signal from the second input terminal. The feedback circuit is configured to receive an output signal of the operational amplifier and generate a first feedback signal to the first terminal of the operational amplifier to reduce a swing of the first signal, and generate a second feedback signal to the second terminal of the operational amplifier to balance noises induced by the feedback circuit and inputted to the first terminal and the second terminal.