A noise ring oscillator based on the same type of mos transistor

Abstract

The application discloses a noise cyclic oscillator based on same type MOS transistors, comprising an active core circuit composed of full NMOS or full PMOS transistors, a main LC resonator circuit and two parallel LC resonant loops; the full NMOS or full PMOS transistors compose the active core circuit, which is used for realizing a negative resistance circuit, wherein the negative resistance circuit provides a negative resistance required by the oscillator to work and contributes noise; the main LC resonator circuit is connected with the active core circuit and is used for constituting a resonant circuit through an inductor and a capacitor; the two parallel LC resonant loops are connected with the active core circuit and are used as loads of the active core circuit, the application can realize a phase noise offset technology at a low power supply voltage to reduce overall circuit power consumption, the full NMOS transistors have large transconductance and small overall parasitic capacitance, so that low phase noise and wide frequency tuning range can be realized.

Description

Technical Field

[0001] This invention relates to a noisy cyclic oscillator based on the same type of MOS transistor, belonging to the field of microelectronics technology. Background Technology

[0002] Voltage-controlled oscillators (VCOs) are the core component of phase-locked loops (PLLs), and oscillator circuits with low power consumption, small area, and good phase noise are of great value. Summary of the Invention

[0003] The purpose of this invention is to overcome the shortcomings of the prior art and provide a noise cyclic oscillator based on the same type of MOS transistor. It can realize phase noise cancellation technology under low power supply voltage to reduce the overall circuit power consumption. The all-NMOS transistor has a large transconductance and a small overall parasitic capacitance to achieve low phase noise and a wide frequency tuning range.

[0004] To achieve the above objectives, the present invention is implemented using the following technical solution:

[0005] In a first aspect, the present invention provides a noise cyclic oscillator based on the same type of MOS transistors, including an active core circuit composed of all NMOS or all PMOS transistors, a main LC resonator circuit and two parallel LC resonant circuits.

[0006] The all-NMOS transistors or all-PMOS transistors constitute the active core circuit, which is used to implement the negative resistance circuit, wherein the negative resistance circuit provides the negative resistance required for the oscillator to operate and contributes noise.

[0007] The main LC resonator circuit is connected to the active core circuit and is used to form a resonant circuit through inductors and capacitors.

[0008] The two parallel LC resonant circuits are connected to the active core circuit and are used as the load of the active core circuit.

[0009] Furthermore, the all-NMOS transistors constitute an active core circuit, including transistors MN1, MN2, MN3, and MN4; wherein the gate and source of transistor MN3 are respectively connected to the drain and source of MN1, and the gate and source of MN4 are respectively connected to the drain and source of MN2; the sources of transistors MN3 and MN1 are connected to one load terminal, and the sources of transistors MN2 and MN4 are connected to another load terminal; the drains of MN3 and MN4 are respectively connected to the power supply voltage, wherein the sources of MN3 and MN4 are respectively connected to the sources of MN1 and MN2 to form a common drain stage, and the common drain stage and the negative resistance circuit constitute a noise loop structure.

[0010] Furthermore, the all-PMOS transistors constitute an active core circuit, including transistors P1, P2, P3, and P4; wherein the gate and source of transistor P3 are respectively connected to the drain and source of P1, and the gate and source of P4 are respectively connected to the drain and source of P2; the sources of transistors P3 and P1 are connected to one load terminal, and the sources of transistors P2 and P4 are connected to another load terminal; the drains of P3 and P4 are respectively connected to the power supply voltage, wherein the sources of P3 and P4 are respectively connected to the sources of P1 and P2 to form a common drain stage, and the common drain stage and the negative resistance circuit constitute a noise loop structure.

[0011] Furthermore, when the main LC resonator circuit is connected to the all-NMOS transistor to form an active core circuit, the resonant circuit includes an inductor L1 and a capacitor C1; the drain and gate nodes of active devices MN1 and MN2, and the gates of transistors MN3 and MN4 are respectively connected to the main LC resonator circuit to form positive feedback and generate negative resistance.

[0012] Furthermore, when the main LC resonator circuit is connected to the all-PMOS transistor to form an active core circuit, the resonant circuit includes an inductor L4 and a capacitor C4; the drain and gate nodes of the active devices P1 and P2, and the gates of transistors P1 and P2 are respectively connected to the main LC resonator circuit to form positive feedback and generate negative resistance.

[0013] Furthermore, when the two parallel LC resonant circuits are connected to the all-NMOS transistor to form an active core circuit, the two parallel LC resonant circuits include LC resonant circuit 1 composed of inductor L3 and capacitor C3 and LC resonant circuit 2 composed of inductor L2 and capacitor C2. The parallel connection of inductor L3 and capacitor C3 serves as one load of the active device NMOS transistor, and the parallel connection of inductor L2 and capacitor C2 serves as the other load of the active device NMOS transistor, serving as the tail current source of the active device.

[0014] Furthermore, when the two parallel LC resonant circuits are connected to the full PMOS transistor to form an active core circuit, the two parallel LC resonant circuits include an LC resonant circuit 3 composed of inductor L6 and capacitor C6 and an LC resonant circuit 4 composed of inductor L5 and capacitor C5. The parallel connection of inductor L6 and capacitor C6 serves as one load of the active device PMOS transistor, and the parallel connection of inductor L5 and capacitor C5 serves as another load of the active device PMOS transistor, serving as the tail current source of the active device.

[0015] Compared with the prior art, the beneficial effects achieved by the present invention are as follows:

[0016] This invention provides a noise-cycled oscillator based on the same type of MOS transistors. Compared with traditional cross-coupled oscillators, the active core circuit of the noise-cycled oscillator greatly reduces the contribution of phase noise from negative resistance devices, improves the quality factor, and the all-NMOS or all-PMOS structure eliminates the traditional transistor stacking, allowing it to operate at extremely low power supply voltages. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of a noise cyclic oscillator based on all NMOS transistors provided in an embodiment of the present invention;

[0018] Figure 2 This is a schematic diagram of a noise cyclic oscillator based on all-PMOS transistors provided in an embodiment of the present invention. Detailed Implementation

[0019] The present invention will be further described below with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and should not be used to limit the scope of protection of the present invention.

[0020] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art will understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0021] Example 1

[0022] This embodiment introduces a noise cyclic oscillator based on the same type of MOS transistors, including an active core circuit composed of all NMOS or all PMOS transistors, a main LC resonator circuit, and two parallel LC resonant circuits.

[0023] The all-NMOS transistors or all-PMOS transistors constitute the active core circuit, which is used to implement the negative resistance circuit. The negative resistance circuit provides the negative resistance required for the oscillator to operate and contributes noise. The active transistor structure can realize the circulation of its device noise inside the MOS transistor, reducing its contribution to the phase noise of the oscillator.

[0024] The main LC resonator circuit is connected to the active core circuit and is used to form a resonant circuit through inductors and capacitors to ensure the oscillator starts oscillating.

[0025] The two parallel LC resonant circuits are connected to the active core circuit and are used as the load of the active core circuit.

[0026] The technical concept of this invention is that the negative resistance circuit provides the negative resistance required for the oscillator to operate and contributes noise. The common-drain stage composed of active devices and the negative resistance circuit form a noise loop structure, reducing the contribution of the negative resistance circuit's noise to the phase noise. The tail current source is composed of an LC resonant circuit consisting of an inductor and capacitor, or a resistor or transistor current source can also be used. The active core circuit of the noise loop greatly reduces the contribution of the negative resistance device's phase noise, improves the quality factor, and the all-NMOS or all-PMOS structure eliminates the traditional transistor stacking, allowing operation at extremely low supply voltages.

[0027] like Figure 1 As shown, the active core circuit for noise cycling of all NMOS transistors includes transistors MN1, MN2, MN3, and MN4; wherein the gate and source of transistor MN3 are connected to the drain and source of MN1, respectively, and the gate and source of MN4 are connected to the drain and source of MN2, respectively; the sources of transistors MN3 and MN1 are connected to one load terminal, and the sources of transistors MN2 and MN4 are connected to another load terminal; the drains of MN3 and MN4 are connected to the power supply voltage.

[0028] like Figure 2 As shown, the active core circuit for noise cycling of all PMOS transistors includes transistors P1, P2, P3, and P4; wherein the gate and source of transistor P3 are connected to the drain and source of P1, respectively, and the gate and source of P4 are connected to the drain and source of P2, respectively; the sources of transistors P3 and P1 are connected to one load terminal, and the sources of transistors P2 and P4 are connected to another load terminal; the drains of P3 and P4 are connected to the power supply voltage.

[0029] like Figure 1 As shown, the main LC resonator circuit is used to ensure the oscillator starts oscillating through a resonant circuit composed of an inductor and a capacitor. The main resonant circuit includes an inductor L1, a capacitor C1, the drain and gate nodes of active devices MN1 and MN2, and the gates of transistors MN1 and MN2 are respectively connected to the main LC resonator circuit to form positive feedback and generate negative resistance. The sources of MN3 and MN4 are respectively connected to the sources of MN1 and MN2 to form a common drain stage. The common drain stage and the negative resistance circuit constitute a noise loop structure.

[0030] like Figure 2 As shown, the main LC resonator circuit is used to ensure the oscillator starts oscillating through a resonant circuit composed of an inductor and a capacitor. The main resonant circuit includes an inductor L4, a capacitor C4, and the drain and gate nodes of active devices P1 and P2. The gates of transistors P1 and P2 are respectively connected to the main LC resonator circuit to form positive feedback and generate negative resistance. The sources of P3 and P4 are respectively connected to the sources of P1 and P2 to form a common drain stage. The common drain stage and the negative resistance circuit constitute a noise loop structure.

[0031] In this embodiment, two separate parallel LC energy storage circuits are used as loads for the active transistor.

[0032] Among them, the parallel connection of inductor L3 and capacitor C3 serves as one load of the active device NMOS transistor, and the parallel connection of inductor L2 and capacitor C2 serves as another load of the active device NMOS transistor, serving as the tail current source of the active device; the parallel connection of inductor L6 and capacitor C6 serves as one load of the active device PMOS transistor, and the parallel connection of inductor L5 and capacitor C5 serves as another load of the active device PMOS transistor, serving as the tail current source of the active device.

[0033] In summary, the advantage of the structure in this embodiment is that only a portion of the noise from the transistor reaches the energy storage circuit and generates phase noise, while the remaining noise actually circulates within the transistor and does not generate phase noise. Therefore, the active core circuit with noise cycling greatly reduces the contribution of phase noise from negative resistance devices, improves the quality factor, and the all-NMOS or all-PMOS structure eliminates traditional transistor stacking, allowing it to operate at extremely low supply voltages.

[0034] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A noisy cyclic oscillator based on the same type of MOS transistor, characterized in that, It includes an active core circuit composed of all NMOS transistors or all PMOS transistors, a main LC resonator circuit, and two parallel LC resonant circuits. When the all-NMOS transistors constitute an active core circuit, it includes: transistor MN1, transistor MN2, transistor MN3, and transistor MN4; wherein the gate and source of transistor MN3 are respectively connected to the drain and source of transistor MN1, and the gate and source of transistor MN4 are respectively connected to the drain and source of transistor MN2; the sources of transistor MN3 and transistor MN1 are connected to one load terminal, and the sources of transistor MN2 and transistor MN4 are connected to another load terminal; the drains of transistor MN3 and transistor MN4 are respectively connected to the power supply voltage, wherein the sources of transistor MN3 and transistor MN4 are respectively connected to the sources of transistor MN1 and transistor MN2 to form a common source, and the common source and the negative resistance circuit composed of transistor MN1 and transistor MN2 constitute a noise loop structure; When the all-PMOS transistors constitute an active core circuit, it includes: transistor P1, transistor P2, transistor P3, and transistor P4; wherein the gate and source of transistor P3 are respectively connected to the drain and source of transistor P1, and the gate and source of transistor P4 are respectively connected to the drain and source of transistor P2; the sources of transistor P3 and transistor P1 are connected to one load terminal, and the sources of transistor P2 and transistor P4 are connected to another load terminal; the drains of transistor P3 and transistor P4 are respectively connected to the power supply voltage, wherein the sources of transistor P3 and transistor P4 are respectively connected to the sources of transistor P1 and transistor P2 to form a common source, and the common source and the negative resistance circuit composed of transistor P1 and transistor P2 constitute a noise loop structure; The main LC resonator circuit is connected to the active core circuit and is used to form a resonant circuit through inductors and capacitors. The two parallel LC resonant circuits are connected to the active core circuit and are used as the load of the active core circuit.

2. The noise cyclic oscillator based on the same type of MOS transistor according to claim 1, characterized in that, When the main LC resonator circuit is connected to the all-NMOS transistors to form an active core circuit, the resonant circuit includes an inductor L1 and a capacitor C1; the drain nodes of transistors MN1 and MN2, the gate nodes of transistors MN1 and MN2, and the gates of transistors MN3 and MN4 are respectively connected to the main LC resonator circuit to form positive feedback and generate negative resistance.

3. The noise cyclic oscillator based on the same type of MOS transistor according to claim 1, characterized in that, When the main LC resonator circuit is connected to the all-PMOS transistor to form an active core circuit, the resonant circuit includes an inductor L4 and a capacitor C4; the drain nodes of transistors P1 and P2, the gate nodes of transistors P1 and P2, and the gates of transistors P3 and P4 are respectively connected to the main LC resonator circuit to form positive feedback and generate negative resistance.

4. The noise cyclic oscillator based on the same type of MOS transistor according to claim 1, characterized in that, When the two parallel LC resonant circuits are connected to the all-NMOS transistor to form an active core circuit, the two parallel LC resonant circuits include LC resonant circuit 1 composed of inductor L3 and capacitor C3 and LC resonant circuit 2 composed of inductor L2 and capacitor C2. The parallel connection of inductor L3 and capacitor C3 serves as one load of the active device NMOS transistor, and the parallel connection of inductor L2 and capacitor C2 serves as the other load of the active device NMOS transistor, serving as the tail current source of the active device.

5. The noisy cyclic oscillator based on the same type of MOS transistor according to claim 1, characterized in that, When the two parallel LC resonant circuits are connected to the full PMOS transistor to form an active core circuit, the two parallel LC resonant circuits include LC resonant circuit 3 composed of inductor L6 and capacitor C6 and LC resonant circuit 4 composed of inductor L5 and capacitor C5. The parallel connection of inductor L6 and capacitor C6 serves as one load of the active device PMOS transistor, and the parallel connection of inductor L5 and capacitor C5 serves as the other load of the active device PMOS transistor, serving as the tail current source of the active device.

Images