Earphone Jack Bias Voltage Control for Popping Noise
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Solution Overview
Problem
Conventional earphone jack devices in portable electronic devices can generate instantaneous pulse electric potentials when an earphone plug is inserted, leading to popping noise and potential damage due to sudden changes in bias voltage.
Innovation Solution
The earphone jack device incorporates a power management integrated circuit (PMIC) module with a second bias voltage interface and a filter circuit, which detects the insertion of an earphone plug and generates a second bias voltage only after correct connection, preventing sudden voltage changes and ensuring stable operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the MSM module generates bias voltage to actuate the audio signal processor module during phone calls or audio playback, then the audio function is enabled, but inserting an earphone plug causes sudden voltage changes that generate instantaneous pulse electric potentials leading to popping noise and potential damage
Solution Approach 1:
The patent segments the bias voltage supply into two independent paths: one for the audio signal processor module (controlled by MSM module) and another for the earphone plug (controlled by PMIC module). This segmentation allows independent control of voltage application, preventing the sudden voltage changes that cause popping noise while maintaining audio functionality.
Solution Approach 2:
The patent introduces a PMIC module as an intermediary between the MSM module and the earphone plug. This intermediary detects plug insertion and controls the timing of bias voltage application to the earphone, ensuring voltage is applied only after proper connection is detected, thereby preventing instantaneous pulse electric potentials.
2Productivity
If the bias voltage is applied immediately when the plug is inserted, then the earphone is quickly actuated, but this causes sudden voltage changes that generate instantaneous pulse electric potentials
Solution Approach 1:
The patent implements preliminary detection of plug insertion before applying bias voltage. The PMIC module detects the presence of the plug and verifies proper connection beforehand, then activates the bias voltage only after confirmation. This preliminary action prevents instantaneous pulse electric potentials while ensuring quick earphone actuation.
Solution Approach 2:
The patent applies preliminary anti-action by detecting plug insertion and preparing the voltage control system in advance, then preventing voltage application until proper connection is confirmed. This counteracts the potential harmful effect of sudden voltage changes before they can occur.
Data Source
AI summary
A portable electronic device includes an earphone jack device for connecting a plug of an earphone and a main circuit board. The main circuit board includes an audio signal processor module connected to the earphone jack device, an MSM module connected to the audio signal processor module, and a PMIC module connected to the earphone jack device. The MSM module generates a first bias voltage inputted into the audio signal processor module to actuate the audio signal processor module to play audio signals, and the PMIC module generates a second bias voltage inputted to the earphone jack device to actuate the earphone connected to the earphone jack device.