Phase-locked loop

Abstract

The invention relates to the technical field of electronic communication, and discloses a phase-locked loop, which comprises a tuning voltage generation unit, a tuning voltage detection unit, a bidirectional sub-band counting unit, an adjustment amplitude control unit and a voltage-controlled oscillator; in actual use, the output frequency sub-band of the voltage-controlled oscillator is controlled through an output signal of the bidirectional sub-band counting unit; then an output signal of the bidirectional sub-band counting unit is determined by a counting direction and an adjusting amplitude, the counting direction is input by the tuning voltage detection unit, and the adjusting amplitude is input by the adjusting amplitude control unit, so that the frequency of the phase-locked loop does not need to be adjusted one by one; and therefore, the sub-band selection time of the phase-locked loop can be shortened according to the multi-stage adjustment of the difference between the reference frequency and the output frequency of the voltage-controlled oscillator.

Description

technical field [0001] The invention relates to the technical field of electronic communication, in particular to a phase-locked loop. Background technique [0002] Phase-locked loop is a negative feedback control system that uses the voltage generated by phase synchronization to tune the voltage-controlled oscillator to generate the target frequency. Its frequency purity is very high, and it is often used in frequency stabilization of radio transceivers, communication modulation and demodulation and other fields. [0003] Since the existing phase-locked loop requires stabilization time from start to stabilization, so for the receiver, the length of the stabilization time is crucial to its fast response. At present, the stabilization time of the phase-locked loop includes the sub-band selection time and the dynamic response time determined by the characteristics of the phase-locked loop itself, and the sub-band rotation time accounts for a large proportion of the stabilizat...

AI Technical Summary

Problems solved by technology

In low-cost applications, the first solution has a simple circuit, and its high reliability has won the favor of most designers, but its main problem is that it takes a long time to detect whether the voltage is stable during the detection process, and it is a first-level It took a long time to switch from the first level to the ideal subband

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