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:
Jun. 17, 2025
Filed:
May. 30, 2023
Sigmastar Technology Ltd., Fujian, CN;
SIGMASTAR TECHNOLOGY LTD., Fujian, CN;
Abstract
An audio player device includes a digital-to-analog converter (DAC), a startup circuit, a multiplexer and an output amplifier. The DAC converts audio data into a first signal and a second signal. The startup circuit gradually increases a level of a startup voltage according to a reference voltage during a predetermined period. The multiplexer outputs the startup voltage as a control voltage during the predetermined period, and switches to output the reference voltage as the control voltage after the predetermined period has elapsed. The output amplifier generates an audio signal according to the control voltage, the first signal and the second signal. The control voltage is used to set a common mode voltage of the output amplifier.