Voltage Controlled Oscillator and Its Phase Locked Loop

Abstract

The present application discloses a voltage-controlled oscillator and a phase-locked loop thereof, wherein the voltage-controlled oscillator comprises: a voltage-current conversion circuit, which converts a control voltage into an intermediate current; a noise elimination circuit, which filters a first sampling current of the intermediate current to obtain a filtering current, generates a compensation current according to the filtering current and a second sampling current of the intermediate current, and generates a control current according to the compensation current and the intermediate current; and a current-controlled oscillation circuit, which generates a corresponding oscillation frequency according to the control current. The present application provides a compensation current by using a filtering method to eliminate the noise current of the intermediate current provided by the voltage-current conversion circuit, and provides a control current after the noise current is removed to the current-controlled oscillation circuit to obtain a corresponding oscillation frequency, thereby improving the power supply suppression capability of the voltage-controlled oscillator.

Description

Technical Field

[0001] The present invention relates to the technical field of integrated circuits, and more specifically, to a voltage-controlled oscillator and a phase-locked loop thereof. Background Art

[0002] The voltage controlled oscillator (VCO) is one of the most important modules in the phase-locked loop (PLL). The performance of the voltage controlled oscillator directly reflects the performance of the phase-locked loop. Among the various performance indicators of the voltage controlled oscillator, noise is one of the indicators that has a greater impact on the performance. The noise of the voltage controlled oscillator can be divided into random noise and power supply noise. Random noise mainly includes thermal noise and flicker noise of the device. Power supply noise is one of the sources of deterministic jitter of the voltage controlled oscillator. By improving the power supply noise performance of the voltage controlled oscillator, the power supply rejection capability of the voltage controlled oscillator can be improved.

[0003] The power supply rejection of the voltage-controlled oscillator is one of the important parameters. In the high-performance low-jitter clock generation circuit, with the development of semiconductor technology, the power supply voltage of the chip is getting lower and lower. The traditional way to improve the power supply rejection of the voltage-controlled oscillator has various disadvantages and limitations. For example, the voltage-controlled oscillator currently provided usually uses a low-dropout linear regulator combined with a voltage-stabilizing capacitor to improve the power supply rejection performance of the voltage-controlled oscillator. However, on the one hand, this method requires an additional high-voltage power supply to power the low-dropout linear regulator, which increases the complexity of the circuit; on the other hand, although the low-dropout linear regulator can improve the low-frequency power supply rejection, it requires a larger voltage-stabilizing capacitor to reduce or eliminate higher-frequency power supply noise, which will increase the area of ​​the voltage-controlled oscillator.

[0004] Therefore, there is an urgent need to provide a voltage-controlled oscillator and a phase-locked loop thereof that can improve the power supply rejection capability. Summary of the invention

[0005] In order to solve the problems existing in the above-mentioned prior art, the present application adopts noise elimination technology to provide a control current after the noise current is removed to the current-controlled oscillation circuit, thereby improving the power supply suppression capability of the voltage-controlled oscillator.

[0006] According to one aspect of the present invention, there is provided a voltage controlled oscillator, comprising:

[0007] A voltage-to-current conversion circuit converts the control voltage into an intermediate current;

[0008] a noise elimination circuit, filtering a first sampling current of the intermediate current to obtain a filtering current, generating a compensation current according to the filtering current and a second sampling current of the intermediate current, and generating a control current according to the compensation current and the intermediate current; and

[0009] The current-controlled oscillation circuit is connected to the noise elimination circuit and generates a corresponding oscillation frequency according to the control current.

[0010] Optionally, the noise elimination circuit comprises:

[0011] a sampling module, sampling the intermediate current and outputting a first sampling current and a second sampling current; and

[0012] The compensation module filters the first sampling current and generates a filtering current, generates a compensation current according to the second sampling current and the filtering current, and generates the control current based on the compensation current and the intermediate current.

[0013] Optionally, the compensation module includes:

[0014] a filtering unit, connected to the sampling module to receive the first sampling current, and configured to filter out noise current in the first sampling current and output a filtered current; and

[0015] a compensation unit, connected to the voltage-current conversion circuit to receive the intermediate current, connected to the sampling module to receive the second sampling current, connected to the filtering unit to receive the filtering current, generating the compensation current according to the difference current between the second sampling current and the filtering current, and generating the control current based on the compensation current compensation,

[0016] The compensation current is a mirror current of the difference current.

[0017] Optionally, the noise current in the compensation current and the noise current in the intermediate current are equal in magnitude and opposite in direction.

[0018] Optionally, the filtering unit includes:

[0019] Filter network;

[0020] The first current mirror includes a first MOS tube and a second MOS tube, wherein the control end of the first MOS tube is connected to the first end of the first MOS tube and receives the first sampling current, the second end of the first MOS tube is grounded, the control end of the second MOS tube is connected to the control end of the first MOS tube via the filtering network, the first end of the second MOS tube outputs the filtering current, and the second end of the second MOS tube is grounded.

[0021] Optionally, the compensation unit includes:

[0022] The second current mirror includes a third MOS tube and a fourth MOS tube, wherein the control end of the third MOS tube is connected to the first end of the third MOS tube and receives the second sampling current and the filtering current, the second end of the third MOS tube is grounded, the control end of the fourth MOS tube is connected to the control end of the third MOS tube, the first end of the fourth MOS tube outputs the compensation current, and the second end of the fourth MOS tube is grounded.

[0023] Optionally, the sampling coefficients of the first sampling current and the second sampling current obtained by the sampling module are both The current ratio of the first current mirror is 1:b, and the current ratio of the second current mirror is 1:a.

[0024] Among them, a>1, b<1.

[0025] Optionally, the voltage-current conversion circuit includes:

[0026] a fifth MOS tube, wherein the control of the fifth MOS tube receives the control voltage, a first end of the fifth MOS tube outputs a first current, and a second end of the fifth MOS tube is grounded;

[0027] The third current mirror includes a sixth MOS tube and a seventh MOS tube, wherein the control end of the sixth MOS tube is connected to the first end of the sixth MOS tube and receives the first current, the second end of the sixth MOS tube receives the power supply voltage, the control end of the seventh MOS tube is connected to the control end of the sixth MOS tube, the first end of the seventh MOS tube outputs the intermediate current, and the second end of the seventh MOS tube receives the power supply voltage.

[0028] Optionally, the sampling module includes:

[0029] an eighth MOS tube, wherein the control terminal of the eighth MOS tube is connected to the control terminal of the seventh MOS tube, a first terminal of the eighth MOS tube outputs a first sampling current, and a second terminal of the eighth MOS tube receives the power supply voltage;

[0030] A ninth MOS tube, wherein the control terminal of the ninth MOS tube is connected to the control terminal of the seventh MOS tube, a first terminal of the ninth MOS tube outputs a second sampling current, and a second terminal of the ninth MOS tube receives the power supply voltage.

[0031] Optionally, the filtering network comprises:

[0032] a resistor, one end of which is connected to the control end of the first MOS transistor, and the other end of which is connected to the control end of the second MOS transistor; and

[0033] The capacitor has one end connected to the other end of the resistor and the other end grounded.

[0034] According to another aspect of the present invention, a phase-locked loop is provided, comprising: the voltage-controlled oscillator.

[0035] The voltage-controlled oscillator proposed in the embodiment of the present invention eliminates the noise current of the intermediate current provided by the voltage-to-current conversion circuit by adopting filtering combined with mirror current, and provides the control current after the noise current is removed to the current-controlled oscillation circuit to obtain the corresponding oscillation frequency, thereby improving the power supply suppression capability of the voltage-controlled oscillator and being less affected by PVT.

[0036] Furthermore, the ripple on the control voltage is converted into a noise current through the fifth MOS tube and superimposed on the intermediate current, and can then be removed by the above-mentioned noise elimination circuit to reduce the deterministic jitter of the output clock of the voltage-controlled oscillator. While improving the power supply noise suppression, the deterministic jitter (DJ) caused by the ripple on the control voltage can also be reduced.

[0037] Furthermore, the present application also provides a phase-locked loop with high power supply rejection capability. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] The above and other objects, features and advantages of the present invention will become more apparent through the following description of the embodiments of the present invention with reference to the accompanying drawings.

[0039] Figure 1 A block diagram of a voltage-controlled oscillator provided in the first embodiment of the present application is shown.

[0040] Figure 2 A schematic structural diagram of a voltage-controlled oscillator provided in the second embodiment of the present application is shown.

[0041] Figure 3 A circuit diagram of a voltage-controlled oscillator provided in the third embodiment of the present application is shown.

[0042] Figure 4 A waveform diagram showing power supply rejection indicators of a voltage-controlled oscillator provided in an embodiment of the present application and a conventional voltage-controlled oscillator is shown. DETAILED DESCRIPTION

[0043] The present invention will be described in more detail below with reference to the accompanying drawings. In each of the accompanying drawings, the same elements are represented by similar reference numerals. For the sake of clarity, the various parts in the accompanying drawings are not drawn to scale. In addition, some well-known parts may not be shown in the drawings.

[0044] Many specific details of the present invention are described below, such as device structure, materials, dimensions, processing technology and techniques, so as to more clearly understand the present invention. However, as those skilled in the art will appreciate, the present invention may be implemented without following these specific details.

[0045] It should be understood that the connection / coupling of A and B in the embodiment of the present application means that A and B can be connected in series or in parallel, or A and B are connected through other devices, and the embodiment of the present application is not limited to this.

[0046] The present invention proposes a solution that can be used to improve the power supply rejection of a voltage-controlled oscillator controlled by a low power supply voltage. The following will describe an embodiment of the voltage-controlled oscillator provided by the present application in conjunction with the accompanying drawings.

[0047] Figure 1 A block diagram of a voltage-controlled oscillator provided in the first embodiment of the present application is shown. Figure 2 A schematic structural diagram of a voltage-controlled oscillator provided in the second embodiment of the present application is shown. Figure 3 A circuit diagram of a voltage-controlled oscillator provided in the third embodiment of the present application is shown.

[0048] like Figure 1 As shown, the voltage controlled oscillator 1000 includes a voltage-current conversion circuit 1100, a noise elimination circuit 1200 and a current controlled oscillation circuit 1300. The voltage-current conversion circuit 1100 is used to convert the control voltage Vctrl into an intermediate current I2. The noise elimination circuit 1200 filters the first sampling current I3 of the intermediate current I2 to obtain a filtered current, and generates a compensation current Icomp according to the filtered current and the second sampling current I4 of the intermediate current I2, and generates a control current Ictrl according to the compensation current Icomp and the intermediate current I2. The current controlled oscillation circuit 1300 is connected to the noise elimination circuit 1200, and generates a corresponding oscillation frequency CLK according to the control current Ictrl.

[0049] In the first embodiment, the voltage controlled oscillator 1000 uses the voltage-current conversion circuit 1100 in combination with the circuit structure of the current controlled oscillation circuit 1300 to generate a desired oscillation frequency range, and uses the noise elimination circuit 1200 to eliminate the noise current (the influence of power supply noise on the current) in the intermediate current I2 generated by the voltage-current conversion circuit 1100 to obtain the control current Ictrl which is less affected by the power supply noise, and then provides the control current Ictrl to the current controlled oscillation circuit 1300 to realize the function of the voltage controlled oscillator. Further, the noise elimination circuit 1200 includes a sampling module 1210 and a compensation module 1220. The sampling module 1210 is connected to the voltage-current conversion circuit 1100 and samples the intermediate current I2 to output a first sampling current I3 and a second sampling current I4. The compensation module 1220 filters the first sampling current I3 and generates a filtering current, and generates a compensation current Icomp according to the second sampling current I4 and the filtering current, and compensates the intermediate current I2 based on the compensation current Icomp to generate a control current. Furthermore, the noise current in the compensation current Icomp is equal in magnitude and opposite in direction to the noise current in the intermediate current I2 , so that the control current Ictrl obtained after compensation does not contain the noise current, thereby improving the power supply suppression capability of the voltage-controlled oscillator 1000 .

[0050] Furthermore, in the second embodiment, if Figure 2 As shown. The compensation module 1220 in the noise elimination circuit 1200 includes a filtering unit 1221 and a compensation unit 1222. The filtering unit 1221 is connected to the sampling module 1210 to receive the first sampling current I3, and is used to filter out the noise current in the first sampling current I3 and output the filtered current I5. The compensation unit 1222 is connected to the voltage-current conversion circuit 1100 to receive the intermediate current I2, connected to the sampling module 1210 to receive the second sampling current I4, and connected to the filtering unit 1221 to receive the filtered current I5, and generates a compensation current Icomp according to the difference current between the second sampling current I4 and the filtered current I5, and generates a control current Ictrl based on the compensation current Icomp.

[0051] Furthermore, in the third embodiment, if Figure 3As shown. The filter unit 1221 in the compensation module 1220 in the noise elimination circuit 1200 includes a filter network and a first current mirror. The first current mirror includes a first MOS tube Mn3 and a second MOS tube Mn4, the control end of the first MOS tube Mn3 is connected to the first end of the first MOS tube Mn3 and receives the first sampling current I3, the second end of the first MOS tube Mn3 is grounded, the control end of the second MOS tube Mn4 is connected to the control end of the first MOS tube Mn3 via the filter network, the first end of the second MOS tube Mn4 outputs the filter current I5, and the second end of the second MOS tube Mn4 is grounded. The filter network includes a resistor R and a capacitor C, one end of the resistor R is connected to the control end of the first MOS tube Mn3, and the other end of the resistor R is connected to the control end of the second MOS tube Mn4. One end of the capacitor C is connected to the other end of the resistor R, and the other end of the capacitor C is grounded. The compensation unit 1222 in the compensation module 1220 in the noise elimination circuit 1200 includes a second current mirror. The second current mirror includes a third MOS tube Mn5 and a fourth MOS tube Mn6, the control end of the third MOS tube Mn5 is connected to the first end of the third MOS tube Mn5 and receives the second sampling current I4 and the filtering current I5, the second end of the third MOS tube Mn5 is grounded, the control end of the fourth MOS tube Mn6 is connected to the control end of the third MOS tube Mn5, the first end of the fourth MOS tube Mn6 outputs the compensation current Icomp, and the second end of the fourth MOS tube Mn6 is grounded. Further, the sampling module 1210 obtains the sampling coefficients of the first sampling current I3 and the second sampling current I4, both of which are The current ratio of the first current mirror is 1:b, and the current ratio of the second current mirror is 1:a, where a>1 and b<1.

[0052] The voltage-current conversion circuit 1100 includes a fifth MOS transistor Mn1 and a third current mirror. The control terminal of the fifth MOS transistor Mn1 receives a control voltage Vctrl, the first end of the fifth MOS transistor Mn1 outputs a first current I1, and the second end of the fifth MOS transistor Mn1 is grounded. The third current mirror includes a sixth MOS transistor Mp1 and a seventh MOS transistor Mp2, the control end of the sixth MOS transistor Mp1 is connected to the first end of the sixth MOS transistor Mp1 and to the first end of the fifth MOS transistor Mn1 to receive the first current I1, and the second end of the sixth MOS transistor Mp1 receives a power supply voltage VDD. The control end of the seventh MOS transistor Mp2 is connected to the control end of the sixth MOS transistor Mp1, the first end of the seventh MOS transistor Mp2 outputs an intermediate current I2, and the second end of the seventh MOS transistor Mp2 receives the power supply voltage VDD.

[0053] The sampling module 1210 in the noise elimination circuit 1200 includes an eighth MOS transistor Mp3 and a ninth MOS transistor Mp4. The control terminal of the eighth MOS transistor Mp3 is connected to the control terminal of the seventh MOS transistor Mp2, the first terminal of the eighth MOS transistor Mp3 outputs the first sampling current I3, and the second terminal of the eighth MOS transistor Mp3 receives the power supply voltage VDD. The control terminal of the ninth MOS transistor Mp4 is connected to the control terminal of the seventh MOS transistor Mp2, the first terminal of the ninth MOS transistor Mp4 outputs the second sampling current I4, and the second terminal of the ninth MOS transistor Mp4 receives the power supply voltage VDD.

[0054] The fifth MOS transistor Mn1 in the voltage-current conversion circuit 1100 converts the control voltage Vctrl into the first current I1. The current ratio of the third current mirror is 1:k, which is used to adjust the gain of the voltage-controlled oscillator 1000, and the intermediate current I2 output by the third current mirror is K times the first current I1. Among them, the intermediate current I2 output by the voltage-current conversion circuit 1100 is affected by the power supply noise, and the intermediate current I2 includes a DC component I2DC and an AC component I2AC, that is, I2=I2DC+I2AC, wherein the AC component I2AC is a noise current. Further, the ratio of the seventh MOS transistor Mp2 in the third current mirror to the eighth MOS transistor Mp3 in the sampling module 1210 in the noise elimination circuit 1200 is a:1 (a>1), and the ratio of the seventh MOS transistor Mp2 in the third current mirror to the ninth MOS transistor Mp4 in the sampling module 1210 in the noise elimination circuit 1200 is a:1 (a>1). That is, the first sampling current I3 and the second sampling current I4 are equal, and I3=I4=1 / a*(I2DC+I2AC). The current ratio of the first current mirror in the filter unit 1221 in the compensation module 1220 in the noise elimination circuit 1200 is 1:b (b<1). The first sampling current I3 flows through the first MOS transistor Mn3 and is filtered out of the AC component in the first sampling current I3 after low-pass filtering by the filter network, thereby making the filter current I5 flowing through the second MOS transistor Mn4=b / a*I2DC. The current ratio of the second current mirror in the compensation unit 1222 in the compensation module 1220 in the noise elimination circuit 1200 is 1:a. The current I6 flowing through the third MOS transistor Mn5 in the second current mirror is the difference current of the second sampling current I4 and the filter current I5, that is, I6=(1-b) / a*I2DC+1 / a*I2AC. b<1, so the current flowing through the third MOS tube Mn5 contains an AC component and a DC component for DC establishment. The compensation current Icomp flowing through the fourth MOS tube Mn6 in the second current mirror is (1-b)*I2DC+I2AC. Because its compensation current Icomp is in the opposite direction to the intermediate current I2, the control current Ictrl output by the compensation unit 1222 is I2-Icomp=b*I2DC. That is, the control current Ictrl provided by the noise elimination circuit 1200 to the current control oscillation circuit 1300 does not contain an AC component (noise current). This improves the power supply noise suppression performance of the voltage-controlled oscillator 1000. The appropriate value of b can achieve high-efficiency elimination of the noise current of the intermediate current and is not affected by PVT.

[0055] It should be noted that while improving the power supply noise suppression, the deterministic jitter (DJ) caused by the ripple on the control voltage Vctrl can also be reduced. Specifically, the ripple on the control voltage Vctrl is converted into a noise current through the fifth MOS transistor Mn1 and superimposed on the intermediate current I2, and then can be removed together by the above-mentioned noise elimination circuit 1200 to reduce the deterministic jitter of the output clock of the voltage-controlled oscillator 1000.

[0056] It should be noted that the control end of the above MOS tube is the gate, and the first end and the second end are the source and the drain, or the drain and the source, respectively.

[0057] Figure 4 A waveform diagram showing power supply rejection indicators of a voltage-controlled oscillator provided in an embodiment of the present application and a conventional voltage-controlled oscillator is shown.

[0058] like Figure 4 As shown, waveform S1 is the waveform of the power supply suppression parameter of the voltage-controlled oscillator 1000 provided in the present application, and waveform S2 is the waveform of the power supply suppression parameter of the voltage-controlled oscillator composed of an ordinary current mirror combined with a current-controlled oscillation circuit. To clearly illustrate the present application, illustratively, the parameter values ​​in the voltage-controlled oscillator 1000 are: k=5, a=20, b=9 / 10, R=2Mohm, C=5pF, and the frequency corresponding to the filter network is f=1 / (2pi*R*C)=16kHz. For power supply noise with a frequency lower than 16kHz, the noise elimination circuit 1200 cannot eliminate it. From the results, it can be seen that waveform S1 and waveform S2 almost overlap. For power supply noise with a frequency higher than 16kHz, the noise elimination circuit 1200 can eliminate the noise, and the maximum noise attenuation can reach about 12.9dB, for example; for high-frequency noise, it is actually the voltage division of parasitic capacitance, and the noise elimination circuit cannot eliminate it. The curves of the two are almost overlapping. Subsequently, for example, a decoupling capacitor can be added to the node at the input end of the current-controlled oscillation circuit to improve the performance of high-frequency power supply suppression.

[0059] The present application also provides a phase-locked loop, comprising the voltage-controlled oscillator 1000 described above.

[0060] At the same time, those skilled in the art can realize that, in combination with the structures and methods of the various examples described in the embodiments disclosed herein, different configuration methods or adjustment methods can be used to implement the described functions for each structure or a reasonable deformation of the structure, but such implementation should not be considered to be beyond the scope of the present application. In addition, it should be understood that the connection relationship between the various components of the amplifier in the aforementioned figure in the embodiments of the present application is a schematic example and does not impose any limitation on the embodiments of the present application.

[0061] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the statement "comprise a ..." do not exclude the presence of other identical elements in the process, method, article or device including the elements.

[0062] According to the embodiments of the present invention as described above, these embodiments do not describe all the details in detail, nor do they limit the invention to the specific embodiments described. Obviously, many modifications and changes can be made based on the above description. This specification selects and specifically describes these embodiments in order to better explain the principles and practical applications of the present invention, so that those skilled in the art can make good use of the present invention and the modified use based on the present invention. The present invention is limited only by the claims and their full scope and equivalents.

Claims

1. A voltage-controlled oscillator, characterized in that: include: A voltage-to-current conversion circuit converts the control voltage into an intermediate current; a noise elimination circuit, which filters a first sampling current of the intermediate current and removes a noise current in the first sampling current to obtain a filtering current, generates a compensation current according to the filtering current and a second sampling current of the intermediate current, and generates a control current that does not contain a noise current according to the compensation current and the intermediate current; as well as A current-controlled oscillation circuit is connected to the noise elimination circuit and generates a corresponding oscillation frequency according to the control current. The compensation current is obtained according to the difference current between the second sampling current and the filter current, and the noise current in the compensation current is equal in magnitude and opposite in direction to the noise current in the intermediate current.

2. The voltage controlled oscillator according to claim 1, characterized in that: The noise elimination circuit comprises: a sampling module, sampling the intermediate current and outputting a first sampling current and a second sampling current; and The compensation module filters the first sampling current and generates a filtering current, generates a compensation current according to the second sampling current and the filtering current, and generates the control current based on the compensation current and the intermediate current.

3. The voltage controlled oscillator according to claim 2, characterized in that: The compensation module comprises: a filtering unit, connected to the sampling module to receive the first sampling current, and configured to filter out noise current in the first sampling current and output a filtered current; and a compensation unit, connected to the voltage-current conversion circuit to receive the intermediate current, connected to the sampling module to receive the second sampling current, connected to the filtering unit to receive the filtering current, generating the compensation current according to the difference current between the second sampling current and the filtering current, and generating the control current based on the compensation current compensation, The compensation current is a mirror current of the difference current.

4. The voltage controlled oscillator according to claim 3, characterized in that: The filtering unit comprises: Filter network; The first current mirror includes a first MOS tube and a second MOS tube, wherein the control end of the first MOS tube is connected to the first end of the first MOS tube and receives the first sampling current, the second end of the first MOS tube is grounded, the control end of the second MOS tube is connected to the control end of the first MOS tube via the filtering network, the first end of the second MOS tube outputs the filtering current, and the second end of the second MOS tube is grounded.

5. The voltage controlled oscillator according to claim 4, characterized in that: The compensation unit comprises: The second current mirror includes a third MOS tube and a fourth MOS tube, wherein the control end of the third MOS tube is connected to the first end of the third MOS tube and receives the second sampling current and the filtering current, the second end of the third MOS tube is grounded, the control end of the fourth MOS tube is connected to the control end of the third MOS tube, the first end of the fourth MOS tube outputs the compensation current, and the second end of the fourth MOS tube is grounded.

6. The voltage controlled oscillator according to claim 5, characterized in that: The sampling coefficients of the first sampling current and the second sampling current obtained by the sampling module are both , the current ratio of the first current mirror is 1:b, the current ratio of the second current mirror is 1:a, Among them, a>1, b<1.

7. The voltage controlled oscillator according to claim 2, characterized in that: The voltage-current conversion circuit comprises: a fifth MOS tube, wherein the control of the fifth MOS tube receives the control voltage, a first end of the fifth MOS tube outputs a first current, and a second end of the fifth MOS tube is grounded; The third current mirror includes a sixth MOS tube and a seventh MOS tube, wherein the control end of the sixth MOS tube is connected to the first end of the sixth MOS tube and receives the first current, the second end of the sixth MOS tube receives the power supply voltage, the control end of the seventh MOS tube is connected to the control end of the sixth MOS tube, the first end of the seventh MOS tube outputs the intermediate current, and the second end of the seventh MOS tube receives the power supply voltage.

8. The voltage controlled oscillator according to claim 7, characterized in that: The sampling module comprises: an eighth MOS tube, wherein the control terminal of the eighth MOS tube is connected to the control terminal of the seventh MOS tube, a first terminal of the eighth MOS tube outputs a first sampling current, and a second terminal of the eighth MOS tube receives the power supply voltage; A ninth MOS tube, wherein the control terminal of the ninth MOS tube is connected to the control terminal of the seventh MOS tube, a first terminal of the ninth MOS tube outputs a second sampling current, and a second terminal of the ninth MOS tube receives the power supply voltage.

9. The voltage controlled oscillator according to claim 4, characterized in that: The filtering network comprises: a resistor, one end of which is connected to the control end of the first MOS transistor, and the other end of which is connected to the control end of the second MOS transistor; and The capacitor has one end connected to the other end of the resistor and the other end grounded.

10. A phase-locked loop, characterized in that: include: A voltage controlled oscillator as claimed in any one of claims 1 to 9.

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