Huawei Technologies Co., Limited

Yongwang Liu

Bingzhao Zhang

Jie Peng

Yanqin Chen

Junming Han

Chunbiao Wu

Embodiments of this application disclose an RC oscillator that amplifies a difference between a first voltage and a second voltage by using a first amplifier and a second amplifier. The first amplifier may include a first amplification circuit and a second amplification circuit. The first amplification circuit and the second amplification circuit may share a same voltage-current conversion circuit. The RC oscillator disclosed in the embodiments of this application not only avoids noise introduced by the first amplifier, but also reduces internal noise of the RC oscillator and a jitter of a clock signal.

RC oscillator

A drive circuit for a serial communications system is provided. The drive circuit may include a mode controller, a pre-drive circuit, and a main drive circuit. The main drive circuit includes multiple mode control switches and at least one pair of differential switches. The mode controller is configured to: generate a mode control signal, and transmit the mode control signal to the main drive circuit. The pre-drive circuit is configured to: convert a differential digital signal into a differential control signal, and transmit the differential control signal to the main drive circuit. The main drive circuit controls on/off states of the multiple mode control switches according to the mode control signal, and works in corresponding working modes. The drive circuit controls the states of the mode control switches in the main drive circuit, so that the main drive circuit works in different working modes.

Converting a mode controlling differential signal in a drive circuit and a driving method

A phase-locked loop circuit, which includes a phase frequency detector, a charge pump, a loop low-pass filter, a first voltage-current converter, a second voltage-current converter, a current-controlled oscillator, a frequency divider, a comparator, and a mode controller, where the mode controller is configured to control the switches SSand Sincluded in the loop low-pass filter to connect or disconnect. Using the phase-locked loop circuit, a voltage value of a second control voltage signal VCprovided for the first voltage-current converter can reach, in a relatively short time, a voltage value of a first control voltage signal VCprovided for the second voltage-current converter, thereby increasing a speed of establishing the phase-locked loop circuit and implementing a quick response of the phase-locked loop circuit.

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Shanghai, China

Yongwang Liu