Shanghai Zhaoxin Semiconductor Co., Ltd.

Via Alliance Semiconductor Co., Ltd.

Yongqi Zhou

Yang Chen

Xiaoguang Wang

A multi-phase clock generator is provided in the application. The multi-phase clock generator includes a first oscillator circuit and a second oscillator circuit. The first oscillator circuit includes a plurality of first delay circuits. The first oscillator circuit receives the first number of multi-phase input clock signals and outputs the second number of first output clock signals, wherein the second number is larger than the first number. The second oscillator circuit is coupled to the first oscillator circuit. The second oscillator circuit includes a plurality of second delay circuits. The second oscillator circuit receives the second number of first output clock signals and outputs the second number of second output clock signals. The number of second delay circuits is less than the number of first delay circuits.

Multi-phase clock generator and method thereof

A time-to-digital convertor comprises a phase frequency detector, a first conversion module, a gated ring oscillator and a counting module. The phase frequency detector outputs a first detection signal and a second detection signal according to a first clock signal and a second clock signal. The first conversion module receives the first detection signal and the second detection signal to generate a first control signal and a second control signal. The gated ring oscillator receives the first and second control signals and outputs a plurality of clock signals according to the pulse width difference between the first and second control signals. The counting module counts the plurality of clock signals to generate the phase difference between the first and second clock signals.

Time to digital converter

An oscillator circuit comprises differential amplifiers connected in series and an auxiliary start circuit. A first output terminal and a second output terminal of each differential amplifier are respectively coupled to a first input terminal and a second input terminal of the next differential amplifier. Said first output terminal of the last differential amplifier is coupled to said second input terminal of the first differential amplifier. Said second output terminal of said last differential amplifier is coupled to said first input terminal of said first differential amplifiers. Said auxiliary start circuit generates a first disturbance signal and a second disturbance signal to said first input terminal and said second input terminal of a second differential amplifier according to said signal state of said first input terminal of a first differential amplifier. Said first different amplifier is one of said differential amplifiers. Said second differential amplifier is another differential amplifier.

Oscillator circuit

An eye pattern generator for generating an eye pattern of an input signal is provided. The eye pattern generator includes first and second comparators and a control circuit. The first comparator receives the input signal, a clock signal, and a first voltage and compares the input signal with the first voltage according to the clock signal to generate a first comparison signal. The second comparator receives the input signal, the clock signal, and a second voltage lower than the first voltage and compares the input signal with the second voltage according to the clock signal to generate a second comparison signal. The control circuit changes at least one of a level of the first voltage and a level of the second voltage according to the first and second comparison signals to form a region boundary between an open-eye region and a closed-eye region of the eye pattern.

Eye pattern generator

A bias-current-control circuit is provided. The bias-current-control circuit includes a transconductance circuit, a constant-current source, and a current-mirror circuit. The transconductance circuit is connected to a node and detects a voltage signal to generate a first current. The constant-current source is connected to the node and generates a tail current. The current-mirror circuit includes a reference current terminal and a bias current terminal, and the reference current terminal is coupled to the node. A second current which flows through the reference current terminal is determined by a current difference between the tail current and the first current. A bias current which flows through the bias current terminal is generated based on the second current. Furthermore, the second current and the bias current are in a predetermined ratio.

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Shanghai, China

Yongqi Zhou