High-speed phase-locked loop oscillator circuit

Abstract

The invention discloses a high-speed phase-locked loop oscillator circuit. The high-speed phase-locked loop oscillator circuit comprises a phase discriminator, a charge pump, a voltage-controlled oscillator, a loop filter and a feedback frequency divider, wherein the voltage-controlled oscillator and the loop filter are respectively connected with the charge pump; the feedback frequency divider is connected with the output end of the voltage-controlled oscillator; the charge pump is connected with the phase discriminator; the phase discriminator is used for generating phase control signals; the voltage-controlled oscillator is a loop oscillator which comprises a four-stage differential delay module and a feedforward path; the feedforward path is used for enabling the differential delay module to receive an input signal in advance so as to enable the voltage-controlled oscillator to oscillate at a high frequency. Through the manner, the feedforward path is additionally arranged on the four-stage differential delay module of the high-speed phase-locked loop oscillator circuit, so that the differential delay module can receive the input signal in advance; the delay time is shortened under the same power consumption and process; the voltage-controlled oscillator can oscillate at the higher working frequency.

Description

technical field [0001] The invention relates to an internal circuit of a phase-locked loop, in particular to a high-speed phase-locked loop oscillator circuit. Background technique [0002] In the field of high-speed serial communication, the phase-locked loop (PLL) is a very important module. It generates the clock signal required in both data transmission and reception engineering. The voltage-controlled oscillator (VCO) is the most important module inside the PLL, and its design determines the speed, accuracy and stability of the PLL clock. [0003] see figure 1 , figure 2 , the classic VCO structure is a ring oscillator (Ring OSC) composed of four-stage differential delay modules. The control voltage Vconin is first converted into a control current, and the control current acts on the entire loop. Different currents cause the delay module to have different delay times, resulting in different oscillation frequencies. [0004] Traditional VCO structures work well in...

AI Technical Summary

Problems solved by technology

However, in the 5G USB3.0 circuit, due to the need for high stability, the size of the device is relatively large, so the parasitic resistance and capacitance are also relatively large, making it difficult to reach the oscillation frequency of 5G

Images