Electrical audio signal processing systems and devices – Headphone circuits
Reexamination Certificate
2008-03-03
2011-11-22
Le, Huyen D (Department: 2614)
Electrical audio signal processing systems and devices
Headphone circuits
C381S113000, C381S384000
Reexamination Certificate
active
08064613
ABSTRACT:
The coupling of an electret microphone is detected and identifying whether there is monaural or stereo speakers coupled to the USB connector is accomplished by coupling a current source to the USB ID terminal and detecting the voltage on the ID terminal. If the voltage on the ID line is substantially below the voltage associated with any other accessory when an electret microphone is coupled between the ID terminal and the ground terminal, and a microphone bias resistor is coupled to the ID line. On detection of an electret microphone being coupled between the ID terminal and the ground terminal, whether there is a monaural or stereo speakers coupled to the USB connector is determined by detecting the impedance on the one of the D+ and D− terminals to which a monaural speaker would not be coupled. An open circuit indicates a monaural speaker, otherwise stereo speakers are connected. An alternate embodiment is disclosed.
REFERENCES:
patent: 7623667 (2009-11-01), Sander et al.
patent: 7869608 (2011-01-01), Sander et al.
patent: 7937109 (2011-05-01), Wilson
patent: WO-2008/014422 (2008-01-01), None
Blakely , Sokoloff, Taylor & Zafman LLP
Le Huyen D
Maxim Integrated Products Inc.
LandOfFree
Electret microphone detection using a current source does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Electret microphone detection using a current source, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Electret microphone detection using a current source will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-4288775