Charge pump phase locking loop adopting two voltages for control of voltage-controlled oscillator

Abstract

The invention provides a charge pump phase locking loop adopting two voltages for control of a voltage-controlled oscillator. The phase locking loop comprises an N-stage ring oscillator B200 and an amplifying and shaping circuit B201; the N-stage ring oscillator receives two control voltages respectively generated by a charge pump and a loop filter of the charge pump phase locking loop, and generates sine-wave oscillation signals at a certain frequency according to the control voltages; and the sine-wave oscillation signals are shaped into square-wave oscillation signals which serve as input signals of a digital frequency divider of the charge pump phase locking loop. Compared with the traditional voltage-controlled oscillator, the charge pump phase locking loop provided by the invention has the advantages that the two control voltages VC1 and VC2 serve as tuning voltages, VC1 serves as a coarse tuning voltage, and VC2 serves as a fine tuning voltage, so that both a high tuning speed and a high oscillation signal quality can be guaranteed, and the locking of the charge pump phase locking loop can be effectively accelerated.

Description

technical field [0001] The invention relates to a phase-locked loop of a charge pump using dual-circuit voltages to control a voltage-controlled oscillator, and belongs to the technical field of integrated circuits. Background technique [0002] Phase-locked loop is a frequency and phase synchronization technology realized by feedback control principle, which can provide low-noise clock signal, and has been widely used in wireless communication, navigation, computer and other fields. The charge pump phase-locked loop is a typical representative of the digital-analog hybrid phase-locked loop. Its theoretical static phase error is zero, and it has significant advantages such as high speed, low jitter, and low power consumption. It is currently the most widely used phase-locked loop. The basic structure of the charge pump phase-locked loop is as follows: figure 1 shown. [0003] With the continuous improvement of integrated circuit technology and continuous increase in scale,...

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Problems solved by technology

[0004] At present, most common charge pump phase-locked loops use a voltage-controlled oscillator structure with a single control voltage. The locking speed of the phase-locked loop is improved through bandwidth switching or pre-start strategies. The main problem is that additional circuit modules need to be designed, which increases hardware consumption. and layout area, while bringing about an increase in power consumption, which is not conducive to integration

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