Title:
AUDIO PROCESSING CIRCUIT AND TERMINAL DEVICE
Document Type and Number:
WIPO Patent Application WO/2018/233363
Kind Code:
A1
Abstract:
An audio processing circuit and a terminal device. The circuit comprises a cascaded operational amplifier circuit, an output node, and a pull-down circuit. The cascaded operational amplifier circuit is used for amplifying an input voltage, and outputting the amplified voltage to the output node. The cascaded operational amplifier circuit comprises a first operational amplifier circuit and a second operational amplifier circuit. The first operational amplifier circuit is a previous-stage operational amplifier of the second operational amplifier circuit. The first operational amplifier circuit comprises a main operational amplifier and a secondary operational amplifier connected in parallel. One end of the pull-down circuit is coupled to the output node, and the other end of the pull-down circuit is grounded or connected to a common-mode voltage module. The pull-down circuit is used for pulling down the voltage of the output node when the first operational amplifier circuit is turned on. The second operational amplifier circuit is used for turning on the auxiliary operational amplifier, and then controlling the voltage gain of the auxiliary operational amplifier to gradually change from low to high, thereby controlling the voltage of the output node to follow the gradual change of output resistance, i.e., gradually changing from low to high. By using the circuit provided by this solution, POP noises in a process of establishing an operational amplifier path can be effectively suppressed.
Inventors:
YIN DEYANG (CN)
LI JUN (CN)
LI DING (CN)
DU SHUAI (CN)
LI JUN (CN)
LI DING (CN)
DU SHUAI (CN)
Application Number:
PCT/CN2018/083521
Publication Date:
December 27, 2018
Filing Date:
April 18, 2018
Export Citation:
Assignee:
HUAWEI TECH CO LTD (CN)
International Classes:
H04R3/02; H03F3/72
Foreign References:
| US20170063309A1 | 2017-03-02 | |||
| US20120146719A1 | 2012-06-14 | |||
| EP2317644A1 | 2011-05-04 | |||
| CN105048980A | 2015-11-11 | |||
| CN201710487751A | 2017-06-23 |
Other References:
See also references of EP 3641338A4
Attorney, Agent or Firm:
SHENPAT INTELLECTUAL PROPERTY AGENCY (CN)
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