The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Aug. 04, 2015
Filed:
Jul. 02, 2012
Timothy M. Johnson, San Jose, CA (US);
Adriane S. Niehaus, San Jose, CA (US);
Timothy M. Johnson, San Jose, CA (US);
Adriane S. Niehaus, San Jose, CA (US);
Apple Inc., Cupertino, CA (US);
Abstract
Whether an audio output amplifier of an electronic device is connected through an accessory connector to a headphone or a self powered audio device is determined by sensing the signature of the input power signal in an input power line to a voltage regulator circuit that ultimately powers the amplifier. The signature is sensed flowing through a sense circuit that is in series in the input power line while the amplifier outputs a high power, inaudible signal to the connected device. The signature is output to a controller. The controller indirectly determines from the signature, whether the impedance of the connected device is that of (1) a headphone (speaker) for which a headphone amplifier is selected to provide more power for a lower impedance load, or (2) a self powered output device ('line in' input) for which a 'line out' amplifier and isolation resistor are selected to drive a high capacitive load.
Data source: USPTO (United States Patent and Trademark Office) public patent records. Weekly synchronization. How IDiyas builds this profile