Variable High-Pass Filter Circuit for Low-Latency Audio Settling
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Solution Overview
Problem
Existing audio circuit designs that aim to reduce audio latency often compromise audio data recording performance, as they either filter essential low-frequency components or require complex adjustments to achieve short latencies.
Innovation Solution
A circuit design utilizing variable resistors and capacitors that dynamically adjust their resistance and feedback settings based on signal stability, switching between high and low resistance modes to minimize latency while preserving audio performance, employing high-pass filters with adjustable 3-dB corner frequencies to ensure optimal signal processing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of time
If specific resistances and capacitances are used to shorten audio latency, then audio latency is reduced, but audio data recording performance deteriorates
Solution Approach 1:
The patent applies dynamics by making the resistor values variable rather than fixed. The circuit switches between different resistance values (first and second resistance values) depending on the operating state. During the settling period, lower resistance values are used to reduce latency and accelerate signal settling. After settling, higher resistance values are used to preserve audio recording performance by maintaining appropriate time constants with the capacitors.
Solution Approach 2:
The patent changes the electrical parameters (resistance values) of the circuit components based on the operational phase. By adjusting the resistor values in the high-pass filters and feedback paths, the circuit optimizes its time constant parameters dynamically - using smaller time constants during settling to reduce latency, and larger time constants during normal operation to maintain audio quality.
2Loss of time
If low resistance values are used to reduce settling time, then audio latency is shortened, but low-frequency components are filtered out
Solution Approach 1:
The patent dynamically adjusts the resistance values in the high-pass filter circuits based on the operational phase. During the settling period, lower resistance values are applied to reduce the time constant and accelerate settling. After settling is complete, the resistance values are increased to raise the corner frequency of the high-pass filters, thereby preserving low-frequency audio components that would otherwise be attenuated.
Solution Approach 2:
The circuit operates in periodic phases: initially in a settling phase where low resistance values are used to quickly establish stable output, then transitions to a normal operation phase where high resistance values are used to preserve audio fidelity. This periodic switching of resistance values allows the system to achieve both fast settling and good audio quality at different times in the operational cycle.
Data Source
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AI summary
The present invention provides a circuit having a filter with an amplifier circuit for filtering and amplifying an input signal to generate an output signal, wherein a corner frequency of the filter is adjustable to control a settling time of the output signal.