Phase-locked loop circuit and calibration method of characteristic curve of voltage-controlled oscillator

Abstract

A method for calibrating the characteristic curve of a phase-locked loop circuit and a voltage-controlled oscillator, wherein the phase-locked loop circuit includes a frequency and phase detector, a charge pump, a loop filter, a voltage-controlled oscillator, and a frequency divider. The voltage-controlled oscillator includes at least two voltage-controlled oscillator units with different characteristic curves; the phase-locked loop circuit also includes: a frequency comparison unit, a control unit, a reference voltage generation unit and a switch unit. The calibration method of the characteristic curve of the phase-locked loop circuit and the voltage-controlled oscillator provided by the technical solution of the present invention can automatically select the characteristic curve of the voltage-controlled oscillator, improve the overall performance of the phase-locked loop circuit, and improve the performance of the phase-locked loop circuit. Production yield.

Description

technical field [0001] The invention relates to the technical field of integrated circuits, in particular to a method for calibrating the characteristic curves of a phase-locked loop circuit and a voltage-controlled oscillator. Background technique [0002] Phase-locked loop (PLL, Phase-locked loops) circuit is a frequency and phase synchronization technology realized by the principle of feedback control. Its function is to keep the output signal of the circuit synchronized with its external reference signal. When the frequency or phase of the reference signal changes, the PLL circuit will detect this change and adjust the frequency or phase of the output signal through its internal feedback system until the two are resynchronized. This characteristic of the phase-locked loop circuit is widely used in the generation of clock signals. [0003] figure 1 It is a schematic diagram of the structure of a common phase-locked loop circuit. refer to figure 1 , the phase locked lo...

AI Technical Summary

Problems solved by technology

[0009] The invention solves the problem that the performance of the phase-locked loop circuit deteriorates due to the deviation between the actual characteristic curve of the voltage-controlled oscillator and its ideal characteristic curve

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