Headset Phone Jack Multiplexing Microphone and Remote Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Prior art stereo headsets are limited in functionality due to the constraints of phone plugs, which can only support one additional function beyond speakers, such as a microphone or wired remote control, as the fourth ring is shared for these purposes.
Innovation Solution
A headset design that utilizes a phone jack with at least three electrically conductive rings, incorporating both microphone and remote control features on a single ring, along with integrated circuitry including a charge pump, multi-voltage LDO, and ADC, enabling signal multiplexing and supporting multiple control buttons, allowing for both microphone and remote control functionality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a phone plug with four rings is used to support additional functionality beyond speakers, then the headset can include either a microphone or a wired remote control on the fourth ring, but it is limited to only one additional function
Solution Approach 1:
The fourth ring of the phone plug is designed to support multiple functions by implementing a selection mechanism that can switch between microphone mode and wired remote control mode. The circuit includes a microphone connected to the fourth ring and a remote control circuit also connected to the fourth ring, with switching circuitry that selects which function is active based on detection signals. This allows a single connector configuration to serve multiple purposes.
2Adaptability or versatility
If both microphone and wired remote control are integrated into a single headset using a four-ring phone plug, then multifunctionality is achieved, but signal interference between microphone and remote control signals occurs on the shared fourth ring
Solution Approach 1:
The headset implements dynamic switching between microphone and remote control functions based on detected signal conditions. The circuit continuously monitors the fourth ring for specific signal patterns and automatically switches between microphone mode and remote control mode to prevent signal interference. This dynamic adaptation ensures that only one function is active at a time on the shared fourth ring, maintaining signal integrity.
Solution Approach 2:
A detection circuit and switching mechanism serve as intermediaries between the microphone and remote control circuits. The detection circuit monitors signals on the fourth ring and activates the appropriate function while preventing the other from interfering. This intermediary layer isolates the two functions and manages their interaction through the shared connector, preventing mutual interference.
Data Source
AI summary
In an example embodiment a headset includes a phone jack, a speaker connected to the phone jack, a microphone coupled to the phone jack and a resistive switch string coupled to the phone jack to the same ring of the phone jack as the microphone. In another example an integrated circuit device includes a charge pump, a multi-voltage LDO having an input which is capable of being coupled to an output of the charge pump, an ADC; and a pull-up resistor coupled between an output of the LDO and an input of the ADC. In another example embodiment, a method for headset signal multiplexing includes providing a headset with a plurality of signal sources and voltage division multiplexing the plurality of signal sources on a common wire.