KR19980039841A - Circuit to supply stable clock to private exchange system - Google Patents

Abstract

end. The technical field to which the invention described in the claims belongs

Private Exchange System

I. The technical problem that the invention is trying to solve

It prevents the disconnection of the established call path at the moment when the clock supplied to the private exchange system is switched or disconnected and the clock is supplied again.

All. Summary of the Solution of the Invention

A clock selector for selecting and outputting an applied clock, a stabilizer for generating a stable clock by receiving the clock output from the clock selector, and a synchronization unit for receiving and synchronizing a signal output from the stabilizer do.

la. Important uses of the invention

A stable clock can be supplied to the private exchange system to prevent the call from being blocked during a call.

Description

Circuit to supply stable clock to private exchange system

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a circuit for supplying a stable clock to a private exchange system, and more particularly to a circuit for supplying a stable clock to a private exchange system in order to maintain the state of a call path when switching or cutting a clock supplied to a private exchange system. It is about.

Typically, private exchange systems require the supply of a clock to control certain drive operations.

FIG. 1 is a block diagram of a circuit for supplying a clock to a conventional private exchange system, which is comprised of a multiplexer 100 and a phase synchronizer 110. As shown in FIG.

Referring to FIG. 1, the multiplexer 100 receives n reference clocks REF1, REF2,..., REFn, multiplexes them, and outputs them to the phase synchronizer 110. The phase synchronizer 110 receives the signal output from the multiplexer 100 and synchronizes the phase of the selected clock to the private exchange system.

Loss of reference clocks REF1, REF2, ..., REFn is generated by the loss LOSS1, LOSS2, ..., LOSSn in the circuit supplying the clock required for operation in such a conventional private exchange system or the reference clocks REF1, REF2, There is a problem that a disconnection of a communication path formed at the moment when ..., REFn is switched or when the clock is supplied again after cutting or switching.

Accordingly, it is an object of the present invention to provide a circuit for supplying a stable clock to a private exchange system.

Another object of the present invention is to provide a clock supply circuit of a private exchange system for forming a stable communication path.

According to an aspect of the present invention, there is provided a clock selector for selecting and outputting an applied clock, a stabilizer for generating and outputting a stable clock by receiving a clock output from the clock selector, and outputting from the stabilizer. Characterized in that it comprises a synchronization unit for receiving and synchronizing the signal.

1 is a block diagram of a circuit for supplying a clock to a conventional private exchange system.

2 is a block diagram of a circuit for supplying a clock to a private exchange system according to an embodiment of the present invention;

3 is a view showing a specific block configuration of the stabilization unit according to an embodiment of the present invention.

Hereinafter, with reference to the accompanying drawings according to a specific embodiment of the present invention will be described in detail.

FIG. 2 is a block diagram of a circuit for supplying a clock to a private exchange system according to an embodiment of the present invention, and includes a multiplexer 100, a stabilizer 200, and a phase synchronizer 110. As shown in FIG.

3 is a block diagram illustrating a specific circuit configuration of the stabilization unit 200 among the blocks of the circuit for supplying the clock of the private exchange system according to the embodiment of the present invention, wherein the phase detector 302, the low pass filter 304, and the voltage controlled oscillator 306 are divided. Cycle 308.

Referring to FIG. 2, the multiplexer 100 receives n reference clocks REF1, REF2,..., REFn and multiplexes the multiplexed outputs to the stabilizer 200. Stabilizer 200 according to an embodiment of the present invention receives a signal output from the multiplexer 100 generates a stable clock and outputs to the phase synchronizer 110.

Referring to FIG. 3, the stabilization unit 200 according to the embodiment of the present invention includes a phase detector 302, a low pass filter 304, a voltage controlled oscillator 306, and a divider 308, and receives a signal output from the multiplexer 100 to stabilize the clock. Occurs. The phase detector 302 receives the signal output from the multiplexer 100 and the divided signal from the divider 308, detects a phase, and outputs a signal corresponding thereto to the low pass filter 304. The low pass filter 304 receives the signal output from the phase detector 302 and passes only the set low frequency signal to the voltage controlled oscillator 306. The voltage controlled oscillator 306 receives a signal passing through the low pass filter 304 and generates a predetermined voltage. The divider 308 receives a signal output from the voltage controlled oscillator 306 and divides the frequency of the signal to output a predetermined divided signal. The divided signal generated by the divider 308 is fed back to the phase detector 302 and input to the phase synchronizer 110.

The phase synchronizer 110 receives a signal output from the stabilizer 200 and synchronizes it to supply the private private exchange system.

As described above, the present invention has the advantage that it is possible to stably maintain a communication path in a busy state even when switching, cutting, and reflowing a clock supplied to a private exchange system.

Claims (4)

In a circuit for supplying a stable clock to a private exchange system, A clock selector for selecting and outputting an applied clock; A stabilizing unit generating a stable clock by receiving the clock output from the clock selecting unit; And a phase synchronizer configured to receive a signal output from the stabilizer and synchronize a phase thereof. The method of claim 1, And said stabilizing unit comprises an analog phase locked loop circuit. The method of claim 1, The stabilization unit and a phase detector for detecting and outputting the phase of the applied signal; A low pass filter for receiving a signal output from the phase detector and outputting only a low pass of the signal; A voltage controlled oscillator for receiving a signal output from the low pass filter and generating and outputting a control voltage; And a divider which receives the control voltage and divides the frequency of the control voltage to generate and output a predetermined divided signal. In a circuit for supplying a stable clock to a private exchange system, A multiplexer which receives a plurality of clocks and multiplexes the outputs; A stabilizer for receiving a signal output from the multiplexer and generating and outputting a stable clock; And a synchronization unit configured to receive and synchronize a signal output from the stabilization unit.