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. 05, 2007
Filed:
Aug. 17, 2006
Nicolas Marty, Fontaine, FR;
Nicolas Marty, Fontaine, FR;
STMicroelectronics S.A., Montrouge, FR;
Abstract
An audio amplification device includes an input for receiving an input audio signal and an output for delivering an output audio signal and an amplifier (OA) comprising a differential pair of MOS transistors. The gate of the first transistor is coupled to the input of the device. The gate of the second MOS transistor receives a reference voltage which takes the form of a rising ramp when the power is turned on. The drain of one of the transistors is coupled to the output. The amplifier also includes a biasing circuitry for biasing the bulk of the transistors to a first voltage level approximately equal to a supply voltage at the beginning of the reference voltage ramp, and to a second voltage level (V) approximately equal to the voltage of their source at the end of the ramp. The generation of a pop is thus avoided when the power is turned on, while still benefiting from an optimum PSRR in the normal operation phase.