Voltage controlled oscillator circuit

Abstract

The utility model provides a voltage control oscillating circuit that consists of a ring shape oscillating circuit that consists of a plurality of delay circuit units that are connected in series, the output end of the ahead is electrically connected with the input end of the delay circuit unit so as to from a knot; a plurality of controlled delay circuit units, the input end of certain controlled delay circuit unit is electrically connected with the first knot and the second knot of the ring shape oscillating circuit, the amount of the delay circuit units possessed by the first and the second knot is the same, and each controlled delay circuit unit is controlled by a signal to switch between the on status and the off status so as to change the frequency of a plurality of oscillating signals that has different phases and are outputted by the knot. The invention can increase the property of the voltage controlling the oscillating circuit.

Description

technical field [0001] The invention relates to a voltage-controlled oscillator circuit, especially a voltage-controlled oscillator circuit applied in a phase-locked loop clock generator. Background technique [0002] see figure 1 , which is a functional block diagram of a phase locked loop (Phase Locked Loop, referred to as PLL) clock generator (clock generator), which is mainly composed of a phase / frequency detector (Phase / Frequency Detector, referred to as PFD) 1010, a charge pump (charge pump) 1011 , loop filter (Loop Filter) 1012 , voltage controlled oscillator (Voltage Control Oscillator, VCO for short) 1013 , and a frequency divider 1014 and other components. Wherein the phase / frequency detector 1010 outputs an upper signal representing the phase / frequency difference between the two clock signals according to the phase / frequency difference between the reference clock signal Fref and a feedback clock signal output by the frequency divider 1014. count / down signal, whi...

AI Technical Summary

Problems solved by technology

However, in today's increasingly demanding operating frequency range, the method of changing the frequency of the output clock signal only by controlling the delay time of the digital inverter can no longer meet the needs of the current circuit, and how to improve the lack of And increasing the operating frequency range of the voltage controlled oscillator is exactly the main purpose of developing the present invention

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