Charge pump phase-locked loop with adaptive acceleration locking structure

Abstract

The invention discloses a charge pump phase-locked loop with an adaptive acceleration locking structure. The charge pump phase-locked loop with the adaptive acceleration locking structure comprises a frequency and phase discrimination module, a charge pump module, a loop filter module, a voltage-controlled oscillation module and a frequency division module of the conventional charge pump phase-locked loop, and a special adaptive acceleration lock. Such structure can remarkably improve locking speed of the phase-locked loop, and also cannot generate additional jitter for output of the locked phase-locked loop at the same time, and meanwhile, in case of loss of lock caused by external environment, the structure starts by itself to make the loop recover to a steady state quickly.

Description

technical field [0001] The invention relates to a method for realizing a phase-locked loop of a charge pump, in particular to a phase-locked loop of a charge pump with an adaptive acceleration locking structure, which belongs to the field of semiconductor integrated circuits. Background technique [0002] The high-speed serial interface is an interface that more and more integrated circuits need to have. In the high-speed serial interface, a high-precision phase-locked loop is required to be used as a reference clock for data transmission / reception. The phase-locked loop used in the high-speed serial interface Most of the rings are charge pump phase-locked loops with integer frequency division. During the locking process of traditional charge pump phase-locked loops, the phase difference between the input clock signal and the output clock of the phase-locked loop is distinguished by the frequency detector to control the work of the charge pump. The pump generates a correspon...

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Problems solved by technology

[0002] The high-speed serial interface is an interface that more and more integrated circuits need to have. In the high-speed serial interface, a high-precision phase-locked loop is required to be used as a reference clock for data transmission / reception. The phase-locked loop used in the high-speed serial interface Most of the rings are charge pump phase-locked loops with integer frequency division. During the locking process of traditional charge pump phase-locked loops, the phase difference between the input clock signal and the output clock of the phase-locked loop is distinguished by the frequency detector to control the work of the charge pump. The pump generates a corresponding control voltage to control the voltage-controlled oscillation module to oscillate from low frequency to high frequency. The locking time is long, and once the lock is lost, the entire phase-locked loop needs to repeat the same steps to re-enter the stable state. External intervention requires additional The detection and control structure controls the work of the phase-locked loop, which will inevitably bring additional jitter when switching between different states

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