公开(公告)号：US10236832B1

公开(公告)日：2019-03-19

申请号：US16014053

申请日：2018-06-21

Applicant: Airoha Technology Corp.

Inventor： Jia-An Jheng ,  Yu-Hua Liu ,  Ya-Ling Yang

IPC: H03F1/30 ,  H04R3/00 ,  H03F3/187

Abstract: An audio system includes a reference voltage generation circuit to generate a digital encoding signal and generate an analog reference voltage according to the digital encoding signal, wherein, during a booting procedure and/or a shutdown procedure, the analog reference voltage is smoothly increased and/or decreased at a smooth rate related to a bit number of the digital encoding signal; a first analog operational amplifier for receiving the analog reference voltage to generate a common voltage, which is smoothly increased and/or decreased during the booting procedure and/or the shutdown procedure; and a differential analog operational amplifier pair, coupled to the first analog operational amplifier, for receiving a differential audio input signal pair and outputting a differential output voltage pair to drive a load, wherein, during the booting procedure and/or the shutdown procedure, the differential audio output signal pair is smoothly increased and/or decreased.