Phase-locked loop frequency synthesizer

A technology of frequency synthesizer and phase-locked loop, applied in automatic control of power, electrical components, etc., can solve problems such as slow capture, achieve the effect of accelerating the locking process and expanding the range of linear tracking

CN101667830BActive Publication Date: 2013-03-06北京中科微投资管理有限责任公司
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Patent Information

Authority / Receiving Office
CN · China
Patent Type
Patents(China)
Current Assignee / Owner
Publication Date
2013-03-06

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Abstract

The invention provides a phase-locked loop frequency synthesizer comprising a phase detection discriminator and a charge pump, wherein the charge pump comprises an upper power supply and a lower powersupply; the phase-locked loop frequency synthesizer also comprises a first extended circuit and a second extended circuit; the first extended circuit provides a trigger signal for the second extendedcircuit according to the output of the phase detection discriminator; and the second extended circuit provides current together with the upper power supply and the lower power supply under the control of the trigger signal. The phase-locked loop frequency synthesizer broadens the lineal working area by extending the phase detection discriminator / the charge pump, achieves dynamic switch of the charge pump current in a locking process, and accelerates locking process.
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Description

technical field

[0001] The present invention generally relates to the technical field of wireless transceivers, and more specifically, relates to a phase-locked loop frequency synthesizer. Background technique

[0002] The phase-locked loop frequency synthesizer is a key module in the design of the wireless transceiver. It outputs a series of high-precision frequency signals to provide local oscillator signals for the frequency conversion of the transceiver. The commonly used phase-locked loop frequency synthesizer structure is as follows figure 1 As shown, the phase and frequency detector 101, the charge pump 102, the loop filter 103, the voltage controlled oscillator 104 connected in sequence and between the input terminal of the phase frequency detector 101 and the output terminal of the voltage controlled oscillator 104 The frequency divider 105 constitutes.

[0003] The working principle of the phase-locked loop frequency synthesizer is: the phase-frequency detector 1...

Examples

Embodiment Construction

[0037] Embodiments of the present invention will be described in detail below in conjunction with the accompanying drawings. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations to the present invention.

[0038] Compared figure 1 and figure 2 , it can be seen that the PLL frequency synthesizer according to the embodiment of the present invention adds a charge pump extension circuit 204 and a phase detector frequency detector extension circuit 202 on the basis of the traditional PLL frequency synthesizer. Wherein, the charge pump expansion circuit 204 includes: a first current source module, connected in parallel with the upper power supply, for providing current together with the upper power supply after triggering; and a second current source module, connected in parallel with the lower power supply, for triggering Then provide current together with the lower power sup...