Broadband high-precision phase-locked loop circuit

Abstract

The invention discloses a broadband high-precision phase-locked loop circuit which comprises a phase-looked loop 1, a phase-looked loop 2 and a loop selection module. The phase-looked loop 1 is high in loop gain and wide in frequency range and is used for rough locking of frequency points. The phase-looked loop 2 is narrow in loop bandwidth and used for reducing frequency and phase errors and guaranteeing low jitter. The loop selection module realizes operation switching of the phase-looked loop 1 and the phase-looked loop 2 according to digital signals outputted by a digital filter in the phase-looked loop 1. The broadband high-precision phase-locked loop circuit is characterized in that in initial operation, the phase-looked loop 1 high in loop gain is adopted for rough locking of a target frequency point, then the loop selection module controls to switch operation of the phase-looked loop 2, and accurate frequency and phase adjustment is realized. The broadband high-precision phase-locked loop circuit has advantages of wide frequency locking range, quickness in capturing, high precision, high stability and the like.

Description

[0001] The invention relates to the technical field of integrated circuits, in particular to a phase-locked loop circuit with wide frequency band and high precision. Background technique [0002] A phase-locked loop is a control system that can keep the output signal and the reference signal synchronized in frequency and phase, and has become an indispensable basic macro-unit in modern circuit system design. PLL technology is more and more widely used in wireless and communication systems, hard disk drive circuits, wireless transceivers and microprocessors and other fields. The earliest phase-locked loops are composed of pure analog devices. With the improvement of people's requirements for phase-locked loop performance, cost, function and other aspects and the continuous progress of integrated circuit design technology, the types of phase-locked loops are constantly being introduced. , can be divided into the following categories: digital phase-locked loop, all-digital phas...

AI Technical Summary

Problems solved by technology

The traditional analog phase-locked loop has high precision in frequency locking, but the applicable frequency range is narrow, and the application is relatively limited, while the digital phase-locked loop can be applied to a large frequency range and has good anti-interference performance, but because the loop is subject to discrete digital signal control, the final output frequency can only be approximately close to the reference frequency f ref , that is, the frequency locking accuracy is low

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