Integrator Input Error Correction Using Switched Current Sources
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Audio amplifiers face a trade-off between fidelity and power efficiency, particularly in portable devices where fluctuations in input voltage due to feedback currents lead to errors in signal processing, increasing power consumption when attempting to reduce these errors.
Innovation Solution
A circuit with an integrator that includes pull-up and pull-down current sources, controlled by specific signals to manage input current polarity and force the input voltage to zero, thereby correcting voltage fluctuations and maintaining signal fidelity while reducing power consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If feedback current is used to correct signal errors, then signal fidelity is improved, but input voltage fluctuation increases causing processing errors
Solution Approach 1:
The patent introduces an intermediary correction circuit between the feedback path and the integrator input. This circuit includes a correction amplifier and switching elements that actively compensate for voltage fluctuations by injecting correction currents, thereby mediating the conflict between maintaining signal fidelity and preventing voltage instability.
Solution Approach 2:
The patent implements a feedback mechanism where the input voltage fluctuation is detected and used to control switching elements that adjust the feedback current. This feedback loop continuously monitors and corrects voltage deviations, allowing the system to maintain signal fidelity while compensating for the harmful voltage fluctuations caused by feedback current.
2Measurement precision
If integrator bandwidth is increased to reduce voltage error, then signal processing accuracy is improved, but power consumption increases
Solution Approach 1:
The patent employs dynamic switching elements that activate only when voltage fluctuation correction is needed. Rather than continuously operating high-power correction circuits, the switching elements dynamically engage correction mechanisms based on real-time voltage conditions, thereby improving signal processing accuracy while minimizing unnecessary power consumption during stable operating conditions.
Data Source
AI summary
A circuit includes a first amplifier and a second amplifier, wherein first amplifier is configured to receive an input current at a first input of the first amplifier, and an output of the first op-mp is configured to drive a first input of the second amplifier. The circuit further includes a pull-up current source selectively coupled to the first input of the second amplifier, and a pull-down current source selectively coupled to the first input of the second amplifier. If the absolute value of the input current is larger than a predefined threshold current: i) the pull-up current source is configured to drive current into the first input of the second amplifier for a first polarity of the input current, and ii) the pull-down current source is configured to sink current from the first input of the second amplifier for a second polarity of the input current.