CN203504496U

CN203504496U - Voltage-controlled ring oscillator

Info

Publication number: CN203504496U
Application number: CN201320529320.7U
Authority: CN
Inventors: 刘雄
Original assignee: SUZHOU SUERDA INFORMATION TECHNOLOGY Co Ltd
Current assignee: SUZHOU SUERDA INFORMATION TECHNOLOGY Co Ltd
Priority date: 2013-08-29
Filing date: 2013-08-29
Publication date: 2014-03-26
Anticipated expiration: 2023-08-29

Abstract

The utility model relates to a voltage-controlled ring oscillator. The voltage-controlled ring oscillator comprises a phase inverter which is composed of a first MOS transistor, a second MOS transistor and a third MOS transistor, source electrodes of the first MOS transistor and the third MOS transistor are both connected with a direct voltage VAA, grid electrodes of the first MOS transistor and the second MOS transistor are both connected with an input voltage VIN, drain electrodes of the first MOS transistor, the second MOS transistor and the third MOS transistor are all connected with an output voltage VOUT, the grid electrode of the third MOS transistor is connected with and receives a bias current PBIAS. According to the voltage-controlled ring oscillator, the amplitude of the current can be adjusted, and the output frequency can be changed; the delay of a gate circuit is determined by the current of a current source, therefore, the influence of voltage noise on the outputted oscillation frequency is not big, and the contradiction between voltage sensitivity and phase noise is solved.

Description

Annular voltage controlled oscillator

Technical field

The utility model relates to a kind of oscillator, relates in particular to a kind of annular voltage controlled oscillator.

Background technology

Oscillator is divided into voltage controlled oscillator, ring oscillator and LC oscillator.

Described voltage controlled oscillator refers to a kind of oscillator, and its frequency of oscillation will be followed input signal and be changed and change; Described ring oscillator refers to and utilizes the delay of the gate circuits such as inverter to realize self-oscillation, and the number of gate circuit can be odd number or even number, the delay of its frequency of oscillation major decision and single gate circuit and the number of gate circuit; Described LC oscillator refers to that the metal utilizing on chip makes inductance, and with the oscillator that forms inductance capacitance resonant cavity together with electric capacity on chip, its frequency of oscillation depends mainly on the resonance frequency of inductance capacitance resonant cavity.

Generally realize voltage controlled oscillator and can pass through ring oscillator or LC oscillator.The output phase noise of LC oscillator is little, not too responsive to power supply noise; But area is large, cost is high, and adjustable extent is little; Ring oscillator area is little, and adjustable extent can reach one more than the order of magnitude, but output phase noise is large, very responsive to power supply noise.

An existing ring oscillator as shown in Figure 1, in Fig. 1, three phase inverters are together in series, and form loop, and on loop, produce the 360 degree phase differences that have gain, form self-oscillation; Also can be even level, what need be on loop and on loop, to produce the 360 degree phase differences that have gain.Progression is more, and total loop delay is elongated, causes frequency of oscillation to decline.The realization of the phase inverter in Fig. 1 has a lot of modes, as shown in Figure 2, oscillator to the phase inverter based on Fig. 2, in order to change frequency of oscillation, can change supply power voltage VAA, this will change the output rising edge of phase inverter, trailing edge settling time, thereby change the delay of gate circuit, total loop delay is changed, frequency of oscillation changes.

In order to further expand surge frequency range, can add switching tube, change the number of the metal-oxide-semiconductor of working in paraphase, as shown in accompanying drawing 3, by changing the voltage of EN1, EN2, ENB1, ENB2, can make M11, M12, M21, M22 whether work together with M1, M2, change rising edge, trailing edge settling time, change frequency of oscillation.

The shortcoming of foregoing circuit is too responsive to the noise of voltage.The variation of voltage VAA, directly and can affect the delay of phase inverter.

Summary of the invention

Technical problem to be solved in the utility model is that a kind of annular voltage controlled oscillator that can solve the contradiction of voltage-sensitive degree and phase noise is provided.

In order to solve the problems of the technologies described above, the utility model is achieved through the following technical solutions: a kind of annular voltage controlled oscillator, comprise phase inverter, and described phase inverter consists of the first metal-oxide-semiconductor, the second metal-oxide-semiconductor and the 3rd metal-oxide-semiconductor; The source electrode of described the first metal-oxide-semiconductor and the 3rd metal-oxide-semiconductor is all connected direct voltage VAA, the grid of the first metal-oxide-semiconductor and the second metal-oxide-semiconductor is all connected input voltage VIN, the drain electrode of the first metal-oxide-semiconductor, the second metal-oxide-semiconductor and the 3rd metal-oxide-semiconductor is all connected output voltage VO UT, and the grid of the 3rd metal-oxide-semiconductor connects reception bias current PBIAS.

Compared with prior art, usefulness of the present utility model is: this annular voltage controlled oscillator can regulate the size of electric current, change output frequency, because the delay of this gate circuit is determined by the electric current of current source, therefore, the noise of voltage is little on the impact of the frequency of oscillation of output, has solved the contradiction of voltage-sensitive degree and phase noise.

accompanying drawing explanation:

Below in conjunction with accompanying drawing, the utility model is further illustrated.

Fig. 1 is existing ring oscillator circuit structural representation;

Fig. 2 is existing MOS phase inverter circuit structural representation;

Fig. 3 is the MOS phase inverter circuit structural representation of existing variable metal-oxide-semiconductor size;

Fig. 4 and Fig. 5 are the MOS phase inverter circuit structural representations of existing employing current source;

Fig. 6 is MOS phase inverter circuit structural representation in the utility model ring voltage-controlled oscillator circuit;

Fig. 7 is the utility model ring voltage-controlled oscillator circuit structural representation.

In figure: 1, phase inverter; 11, the first metal-oxide-semiconductor; 12, the second metal-oxide-semiconductor; 13, the 3rd metal-oxide-semiconductor.

embodiment:

Below in conjunction with the drawings and the specific embodiments, the utility model is described in detail:

A kind of annular voltage controlled oscillator shown in Fig. 6 and Fig. 7, comprises phase inverter 1, and described phase inverter 1 consists of the first metal-oxide-semiconductor 11, the second metal-oxide-semiconductor 12 and the 3rd metal-oxide-semiconductor 13; The source electrode of described the first metal-oxide-semiconductor 11 and the 3rd metal-oxide-semiconductor 13 is all connected direct voltage VAA, the grid of the first metal-oxide-semiconductor 11 and the second metal-oxide-semiconductor 12 is all connected input voltage VIN, the drain electrode of the first metal-oxide-semiconductor 11, the second metal-oxide-semiconductor 12 and the 3rd metal-oxide-semiconductor 13 is all connected output voltage VO UT, and the grid of the 3rd metal-oxide-semiconductor 13 connects reception bias current PBIAS.

This annular voltage controlled oscillator can regulate by receiving bias current PBIAS the size of electric current, change output frequency, because the delay of this gate circuit is determined by the electric current of current source, therefore, the noise of voltage is little on the impact of the frequency of oscillation of output, has solved the contradiction of voltage-sensitive degree and phase noise.

It is emphasized that: be only preferred embodiment of the present utility model above, not the utility model is done to any pro forma restriction, any simple modification, equivalent variations and modification that every foundation technical spirit of the present utility model is done above embodiment, all still belong in the scope of technical solutions of the utility model.

Claims

1. an annular voltage controlled oscillator, comprises phase inverter (1), it is characterized in that: described phase inverter (1) consists of the first metal-oxide-semiconductor (11), the second metal-oxide-semiconductor (12) and the 3rd metal-oxide-semiconductor (13); The source electrode of described the first metal-oxide-semiconductor (11) and the 3rd metal-oxide-semiconductor (13) is all connected direct voltage (VAA), the grid of the first metal-oxide-semiconductor (11) and the second metal-oxide-semiconductor (12) is all connected input voltage (VIN), the drain electrode of the first metal-oxide-semiconductor (11), the second metal-oxide-semiconductor (12) and the 3rd metal-oxide-semiconductor (13) is all connected output voltage (VOUT), and the grid of the 3rd metal-oxide-semiconductor (13) connects reception bias current (PBIAS).