Huawei Technologies Co., Limited

Shuai Du

Jun Li

Ding Li

Deyang Yin

Yixing Chu

Hongpei Wang

A polysilicon resistor is disclosed, to reduce a voltage coefficient of the polysilicon resistor. The polysilicon resistor includes: a polysilicon layer (), a voltage module (), and a substrate layer (), where the voltage module () is configured to transmit a voltage on the polysilicon layer () to the substrate layer ().

Polysilicon resistor

An example audio play circuit includes a power supply module, a power amplifier, a coupling capacitor, a load, and a plosive suppression circuit. An output terminal of the power amplifier is connected to a first terminal of the coupling capacitor and an output terminal of the plosive suppression circuit, a second terminal of the coupling capacitor is connected to the load, and an output terminal of the power supply module is connected to a power supply terminal of the power amplifier and a power supply terminal of the plosive suppression circuit. The power supply module is configured to provide a direct current power supply voltage for the power amplifier and the plosive suppression circuit. When the direct current power supply voltage rises to the first voltage threshold, the plosive suppression circuit connects the first terminal of the coupling capacitor to the ground terminal.

Audio play circuit and audio play device

An audio processing circuit includes a cascade operational amplifier circuit, an output node, and a pull-down circuit. The cascade operational amplifier circuit includes a first operational amplifier circuit and a second operational amplifier circuit. The first operational amplifier circuit includes a main operational amplifier and a secondary operational amplifier that are connected in parallel. The pull-down circuit is configured to pull down a voltage at the output node after the first operational amplifier circuit is turned on. The second operational amplifier circuit is configured to, after the secondary operational amplifier is turned on, control a voltage gain of the secondary operational amplifier to change gradually from low to high.

Audio processing circuit and terminal device

A pop sound suppression method, an audio output circuit, and a terminal suppress a pop sound that is generated when an audio output circuit is in an alternating current (AC) coupling structure. The output circuit includes an output power amplifier, a common-mode voltage buffer, a reference voltage generation circuit, a powered-on pop sound suppression switch, and a common-mode switch. The powered-on pop sound suppression switch is configured to control, in a power-on process of the audio output circuit, a voltage level of an output node to be zero. The common-mode switch is configured to control, when a reference voltage level of the reference voltage generation circuit is zero, the voltage level of the output node to be equal to the reference level.

Pop sound suppression method, audio output circuit, and terminal

Embodiments of the present invention provide a digital-to-analog conversion circuit, where the digital-to-analog conversion circuit includes a signal amplitude detector and a digital-to-analog converter. When the signal amplitude detector detects a low signal amplitude, a first current module in the digital-to-analog converter operates normally and a second current module in the digital-to-analog converter stops operating. In addition, when stopping operating, the second current module is in a state of a third bias voltage and a fourth bias voltage that are generated by a second bias circuit. When the amplitude detector detects a high signal amplitude subsequently, the second current module resumes normal operation. After operating normally, the second current module switches back to a first bias voltage and a second bias voltage that are generated by a first bias circuit. This reduces a nonlinearity problem caused before a second current module resumes normal operation.

Digital-to-analog conversion circuit

A circuit system including an operational amplification circuit is disclosed. The operational amplification circuit includes N stages of operational amplification units that are cascaded, an input terminal of the 1stage of operational amplification unit is an input terminal of the operational amplification circuit, and an output terminal of the Nstage of operational amplification unit is an output terminal of the operational amplification circuit; an output terminal of the istage of operational amplification unit is connected to an input terminal of the (i+1)stage of operational amplification unit, so as to provide an input signal for the (i+1)stage of operational amplification unit; and there is a feedback channel from the output terminal of the Nstage of operational amplification unit to an input terminal of each of the 1stage of operational amplification unit to the Nstage of operational amplification unit.

Growing community of inventors

Chengdu, China

Shuai Du