Huawei Technologies Co., Limited

Honor Device Co., Ltd.

Yunhai Li

Yang Liu

Shizhe Li

Jing Chang

Lu Feng

Chienfeng Yeh

Haihong Zhang

Chuanguo Wang

Yonghua Zhang

An earphone, including: a housing, a first speaker unit, a second speaker unit. The housing has a sound output hole. The first speaker unit and the second speaker unit are separately independently fastened in the housing. The first speaker unit produces a sound toward the sound output hole. The second speaker unit is located on a side that is of the first speaker unit and that is away from the sound output hole and is spaced apart from the first speaker unit. A sound production frequency of the second speaker unit is smaller than a sound production frequency of the first speaker unit. A cavity is enclosed by the first speaker unit, the second speaker unit, and an inner wall of the housing, the cavity serves as a front cavity of the second speaker unit, and the front cavity communicates with the sound output hole through a sound output channel.

Earphone

A bias circuit and a voltage-controlled oscillator (VCO) thereof suitable for improving the stability of the bias circuit are provided. The bias circuit includes: an error amplifier circuit, having an inverting input terminal connected to a reference voltage; a voltage-controlled current source, having a voltage control terminal connected to a voltage output terminal of the error amplifier circuit, in which a current generated by the current source is controlled by a voltage at the voltage output terminal of the error amplifier circuit; a delay control circuit, having a current input terminal connected to the voltage-controlled current source, an output terminal connected to a non-inverting input terminal of the error amplifier circuit, and a voltage input terminal connected to a supply terminal of the control voltage, and the delay control circuit is adapted to adjust an output voltage of the delay control circuit according to a control voltage.

Bias circuit and voltage-controlled oscillator

Growing community of inventors

Shenzhen, China

Yunhai Li