Phase-locked loop locking indication circuit and phase-locked loop

Abstract

The invention discloses a phase-locked loop locking indication circuit. An analog-digital converter receives a voltage control signal, conducts analog-digital conversion on the voltage control signal and outputs the voltage control signal; a frequency control signal is output by a controller; the voltage control signal acquired after analog-digital conversion and the frequency control signal are received by a field programmable logic array, and when the difference between the voltage control signal acquired after analog-digital conversion and the frequency control signal is smaller than a first threshold value, a locking indication signal is output, and locking indication of the phase-locked loop is achieved; because locking indication is achieved by the phase-locked loop locking induction circuit by detecting the voltage control signal and the frequency control signal and is not related to the value of the output frequency of the phase-locked loop, engineering application on broadband and high frequency application occasions can be achieved, and the phase-locked loop locking indication circuit can be applied to locking indication under high output frequency or broadband frequency synthesis conditions without additional complex circuits.

Description

technical field [0001] The invention relates to the technical field of power electronics, in particular to a phase-locked loop lock indicating circuit and a phase-locked loop. Background technique [0002] A phase-locked loop (PLL for short) has many advantages in implementing frequency synthesis, such as a simple circuit, small size, and flexible frequency configuration, so it is widely used. In high-speed wired communication, it is used for clock generation, clock recovery, etc.; in wireless communication, it is used for the generation of radio frequency local oscillator frequency. [0003] The lock indication function indicates whether the phase-locked loop can be locked normally, which is very important for the status indication and troubleshooting of the phase-locked loop itself and the system to which the phase-locked loop is applied. In the case that the phase detection frequency is not very high, the general phase-locked loop chip itself has the locking indication f...

AI Technical Summary

Problems solved by technology

[0005] In view of this, the present invention provides a phase-locked loop lock indication circuit and a phase-locked loop to solve the problem that the prior art needs to add additional complex circuits to be suitable for lock indication under high output frequency conditions

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