Phase-locked loop circuit capable of reducing phase deviation and not increasing operating voltage

Abstract

A PLL circuit includes a comparator (10), an integrator (20), a phase controller (21), a current control oscillator (14) and a feedback frequency divider (16). The comparator (10) compares a phase of an input signal (fREF) with a phase of a feedback signal (fFB) to generate a comparison result. The integrator (20) generates a first current to control an oscillation frequency of an output signal (fOUT) based on the comparison result. The phase controller (21) controls a phase of the output signal (fOUT) based on the comparison result such that a phase difference between the phase of the input signal (fREF) and the phase of the output signal (fOUT) at a lock state is reduced to generate a second current. The current control oscillator (14) generates the output signal (fOUT). The feedback frequency divider (16) performs a frequency division on the output signal (fOUT) to generate the feedback signal (fFB).

Description

technical field [0001] The present invention relates to a PLL (Phase Locked Loop) circuit. More specifically, the present invention relates to a phase locked loop circuit for reducing phase shift without increasing operating voltage. Background technique [0002] In general, a PLL circuit is known as a basic technology used in various fields such as information processing, communication, and the like. Such as figure 1 The conventional PLL circuit shown in FIG. [0003] The phase-frequency comparator 50 takes the input signal f REF The phase and frequency of are respectively related to the feedback signal f output from the feedback frequency divider 55 FB The phase and frequency of are compared to generate one of an increase signal UP and a decrease signal DOWN, which indicates the error between these two signals. For example, a clock signal from an oscillator (not shown) is used as the input signal f REF . The increase signal UP generated by the phase-frequency compar...

AI Technical Summary

Problems solved by technology

However, the structure implements specific measures of the solution, and it is not enough

Images