Shared Signal Interface Circuit With Inductive Interference Matching
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Solution Overview
Problem
Existing signal transmission circuits face interference issues when transmitting both digital and analog signals through a common interface, leading to reduced digital signal quality and potential communication failures due to the parasitic capacitance of analog switches.
Innovation Solution
A signal transmission circuit with a common interface, a first switch, a second switch, and an interference-resistant branch is implemented, where the interference-resistant branch eliminates the interference of the second switch on the digital signal by using impedance matching circuits, such as inductive branches, to ensure high-quality digital signal transmission.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If digital signal and analog signal are transmitted through the same common interface, then the number of output interfaces is reduced, but the quality of digital signal is reduced and communication failure may occur
Solution Approach 1:
The patent introduces an interference-resistant branch as an intermediary component between the second switch and the common interface. This branch includes an inductor that acts as a mediator to counteract the capacitive interference from the second switch, allowing both digital and analog signals to share the common interface without degrading digital signal quality
Solution Approach 2:
The patent changes the electrical parameters of the circuit by adding an inductor with specific inductance value in the interference-resistant branch. This parameter change creates an inductive reactance that compensates for the capacitive effect of the second switch, thereby improving digital signal transmission quality while maintaining interface multiplexing
2Adaptability or versatility
If analog switch is used for analog signal transmission, then analog signal can be transmitted through common interface, but capacitive interference from analog switch degrades digital signal quality
Solution Approach 1:
The patent applies the counterweight principle by introducing an inductor that produces inductive reactance to counterbalance the capacitive reactance of the second switch. The inductor acts as an electrical 'counterweight' that offsets the harmful capacitive interference, enabling both analog and digital signals to coexist on the common interface without degradation
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
The solution effectively reduces interference from analog switches, guaranteeing the quality of digital signals and ensuring successful communication by offsetting capacitive interference through inductive matching, thereby improving signal quality and meeting HiFi audio standards.
Implementation Method 1
the interference-resistant branch eliminates the interference of the second switch on the digital signal by using impedance matching circuits, such as inductive branches
Implementation Method 2
offsetting capacitive interference through inductive matching
Data Source
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AI summary
Disclosed by the embodiments of the present application is a signal transmission circuit, comprising: a common interface, a first switch, a second switch, and an interference-resistant branch; the common interface is configured to, receive a digital signal through the first switch when the first switch is closed, or to receive an analog signal through the second switch when the second switch is closed; the interference-resistant branch is configured to eliminate an interference of the second switch on the digital signal; a signal input of the interference-resistant branch is configured to receive the digital signal, and a signal output of the interference-resistant branch is connected to a signal input of the first switch; and/or, the signal input of the interference-resistant branch is connected to a signal output of the second switch, and the signal output of the interference-resistant branch is connected to a signal input of the common interface.