Phase lock loop and loop filter therefor

Abstract

This invention relates to a phase-lock loop and its applied loop filter including a first resistor, a first capacitor and an amplifier with a specific gain value, among which, the amplifier has an input end coupled to the input and output ends of the loop filter by the first resistor, the amplifier has an output end coupled to the input end of the amplifier via the first capacitor.

Description

technical field [0001] The invention relates to a loop filter, in particular to a phase-locked loop with a fast setting and small-area loop filter architecture and a loop filter applied thereto. Background technique [0002] In general, there are extremely important timing requirements in electronic or computer systems. Therefore, the periodic pulse signal provided to the system must be precisely synchronized with the reference pulse signal. A Phase Locked Loop (PLL for short) is a widely used circuit, which can precisely control the frequency of an output signal to achieve synchronization with the frequency of an input signal. PLLs are often used in frequency synthesizers, multipliers, dividers, single and multiple pulse signal generators, pulse signal recovery circuits, and wireless communication devices, etc. [0003] figure 1 It is a circuit block diagram of a conventional phase-locked loop. see figure 1 As shown, the output of an oscillator 101 , such as a crystal ...

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Problems solved by technology

However, the charge pump circuit 201 is added, and there will also be a matching problem between the charge pump circuits 107 and 201

[0008] This shows that above-mentioned existing phase-locked loop and the loop filter of its application obviously still have inconvenience and defect in structure and use, and urgently need to be further improved

In order to solve the problems existing in the phase-locked loop and its applied loop filter, the relevant manufacturers have tried their best to find a solution, but for a long time no suitable design has been developed, and the general product has no suitable structure Able to solve the above problems, this is obviously a problem that the relevant industry is eager to solve

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