Power supply noise suppression circuit for voltage-controlled oscillator and electronic device

Abstract

The application discloses a power supply noise suppression circuit of a voltage-controlled oscillator, which comprises a power supply input end, a mean value unit, a noise sampling unit, an integral unit and a proportional addition unit, wherein the power supply input end provides an input voltage; the mean value unit is connected with the power supply input end, and the mean value unit obtains a power supply voltage average value according to the input voltage; the noise sampling unit is connected with the power supply input end and the mean value unit respectively, so as to obtain a power supply voltage instantaneous value according to the input voltage, and obtain a noise signal according to the difference between the power supply voltage average value and the power supply voltage instantaneous value; the integral unit is connected with the noise sampling unit, and the integral unit processes the noise signal to obtain a compensation signal; the proportional addition unit is connected with the integral unit, so as to obtain a voltage control signal of the voltage-controlled oscillator after the compensation signal is compensated; thus, the noise suppression effect is good, and the on-chip integration is easy.

Description

Technical Field

[0001] This invention relates to the field of electronic technology, and in particular to a power supply noise suppression circuit for a voltage-controlled oscillator and an electronic device. Background Technology

[0002] In related technologies, a voltage-controlled oscillator (VCO) is a signal generation unit whose output frequency can be flexibly adjusted by voltage. It is commonly used in high-speed digital integrated circuits in communication systems. Ideally, its voltage-controlled characteristic is that, without other interference, the output frequency changes with the control voltage. However, in actual operation, the output frequency of a VCO fluctuates due to interference. This frequency change manifests as phase jitter in the time domain, and the output waveform is as follows: Figure 1 As shown, the positions of the rising and falling edges become inaccurate; this affects the correctness of the timing logic in digital circuits, reduces the signal-to-noise ratio of communication systems, and in severe cases, makes the system unable to operate; existing suppression circuits usually use inductor-capacitor voltage-controlled oscillators, which require large capacitors and inductors and are not easy to integrate. Summary of the Invention

[0003] The present invention aims to at least partially solve one of the technical problems in the aforementioned technologies. Therefore, one objective of the present invention is to provide a power supply noise suppression circuit for a voltage-controlled oscillator (VCO), which, by adjusting component parameters, achieves significant power supply noise suppression for VCOs with different power supply rejection ratios, thus not only providing good noise suppression but also facilitating on-chip integration.

[0004] To achieve the above objectives, an embodiment of the present invention provides a power supply noise suppression circuit for a voltage-controlled oscillator, comprising: a power input terminal for providing an input voltage; an averaging unit connected to the power input terminal, wherein the averaging unit obtains an average power supply voltage based on the input voltage; a noise sampling unit connected to both the power input terminal and the averaging unit, wherein the noise sampling unit obtains an instantaneous power supply voltage value based on the input voltage and obtains a noise signal based on the difference between the average power supply voltage value and the instantaneous power supply voltage value; an integration unit connected to the noise sampling unit, wherein the integration unit processes the noise signal to obtain a compensation signal; and a proportional summing unit connected to the integration unit, wherein the voltage control signal of the voltage-controlled oscillator is obtained after supplementation with the compensation signal.

[0005] The power supply noise suppression circuit for a voltage-controlled oscillator (VCO) according to an embodiment of the present invention provides an input voltage through a power input terminal; an averaging unit is connected to the power input terminal and obtains the average power supply voltage based on the input voltage; a noise sampling unit is connected to both the power input terminal and the averaging unit to obtain the instantaneous power supply voltage value based on the input voltage, and obtains the noise signal based on the difference between the average power supply voltage value and the instantaneous power supply voltage value; an integration unit is connected to the noise sampling unit and processes the noise signal to obtain a compensation signal; a proportional summing unit is connected to the integration unit to obtain the voltage control signal of the VCO after supplementation with the compensation signal; thus, by adjusting the component parameters, a significant power supply noise suppression effect can be achieved for VCOs with different power supply rejection ratios, resulting in not only good noise suppression effect but also easy on-chip integration.

[0006] In addition, the power supply noise suppression circuit of the voltage-controlled oscillator proposed in the embodiments of the present invention may also have the following additional technical features:

[0007] Optionally, the sampling frequency of the noise sampling unit is the output frequency of the voltage-controlled oscillator.

[0008] Optionally, the output terminal of the proportional summing unit is connected to the input terminal of the voltage-controlled oscillator, and the output terminal of the voltage-controlled oscillator is connected to the first input terminal of the noise sampling unit, so that the output frequency of the voltage-controlled oscillator is used as the sampling frequency of the noise sampling unit.

[0009] Optionally, the averaging unit includes: a first resistor, one end of which is connected to the power input terminal; a first capacitor, one end of which is connected to the other end of the first resistor, and the other end of which is grounded; and a buffer, the input terminal of which is connected between the first resistor and the first capacitor, and the output terminal of which serves as the output terminal of the averaging unit.

[0010] Optionally, the noise sampling unit includes: a first switch transistor, the input terminal of which is connected to the power input terminal; a second switch transistor, the input terminal of which is connected to the output terminal of the first switch transistor and has a first node; a third switch transistor, the input terminal of which is connected to the output terminal of the averaging unit; a fourth switch transistor, the input terminal of which is connected to the output terminal of the third switch transistor and has a second node; a second capacitor, one end of which is connected to the first node and the other end of which is connected to the second node; a first NOT gate, the output terminal of which is connected to the control terminal of the first switch transistor and the input terminal of which is connected to the control terminal of the second switch transistor; and a second NOT gate, the output terminal of which is connected to the input terminal of the first NOT gate and the input terminal of which is connected to the output terminal of the voltage-controlled oscillator.

[0011] Optionally, the first switching transistor includes a first MOSFET and a second MOSFET connected to each other, the second switching transistor includes a third MOSFET and a fourth MOSFET connected to each other, the third switching transistor includes a fifth MOSFET and a sixth MOSFET connected to each other, and the fourth switching transistor includes a seventh MOSFET and an eighth MOSFET connected to each other.

[0012] Optionally, the integration unit includes: a second resistor, one end of which is connected to the output terminal of the second switch; a third capacitor, one end of which is connected to the other end of the second resistor; a third resistor connected in parallel with the third capacitor; and an amplifier, the first input terminal of which is connected between the second resistor and the third capacitor, the second input terminal of which is connected to the output terminal of the fourth switch, the output terminal of which is connected to the other end of the third capacitor, and the output terminal of which serves as the output terminal of the integration unit.

[0013] Optionally, the proportional summing unit includes: a fourth resistor, one end of which is connected to the output terminal of the amplifier, and the other end of which is connected to the input terminal of the voltage-controlled oscillator; and a fifth resistor, one end of which is connected to the second input terminal of the amplifier, and the other end of which is connected to the input terminal of the voltage-controlled oscillator.

[0014] To achieve the above objectives, a second aspect of the present invention provides an electronic device including a power supply noise suppression circuit for a voltage-controlled oscillator as described above.

[0015] The electronic device according to embodiments of the present invention can significantly suppress power noise by adjusting component parameters to achieve different power supply rejection ratios for voltage-controlled oscillators, thereby not only achieving good noise suppression but also being easy to integrate on-chip. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the output waveform of an existing voltage-controlled oscillator;

[0017] Figure 2 This is a circuit diagram of the power supply noise suppression circuit of a voltage-controlled oscillator according to an embodiment of the present invention;

[0018] Figure 3 This is a schematic diagram of the input waveform of the power supply noise suppression circuit of the voltage-controlled oscillator according to an embodiment of the present invention;

[0019] Figure 4 This is a schematic diagram of the output waveform of the power supply noise suppression circuit of the voltage-controlled oscillator according to an embodiment of the present invention;

[0020] Figure 5 This is a schematic diagram of the output waveform of a voltage-controlled oscillator according to an embodiment of the present invention;

[0021] Figure 6 This is a block diagram of an electronic device according to an embodiment of the present invention. Detailed Implementation

[0022] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0023] To better understand the above technical solutions, exemplary embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. Although exemplary embodiments of the present invention are shown in the drawings, it should be understood that the present invention can be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided to enable a more thorough understanding of the present invention and to fully convey the scope of the invention to those skilled in the art.

[0024] To better understand the above technical solutions, the following will provide a detailed explanation of the technical solutions in conjunction with the accompanying drawings and specific implementation methods.

[0025] The power supply noise suppression circuit of the voltage-controlled oscillator according to an embodiment of the present invention will now be described with reference to the accompanying drawings.

[0026] refer to Figure 2As shown, the power supply noise suppression circuit of the voltage-controlled oscillator proposed in this embodiment of the invention includes a power input terminal VDD, an averaging unit 10, a noise sampling unit 20, an integration unit 30, and a proportional summing unit 40.

[0027] The power input terminal VDD is used to provide the input voltage; the averaging unit 10 is connected to the power input terminal VDD, and the averaging unit 10 obtains the average power supply voltage based on the input voltage.

[0028] In other words, the averaging unit 10 processes the input voltage to obtain the average power supply voltage.

[0029] As a specific embodiment, the averaging unit 10 includes a first resistor R1, a first capacitor C1, and a buffer; one end of the first resistor R1 is connected to the power input terminal VDD; one end of the first capacitor C1 is connected to the other end of the first resistor R1, and the other end of the first capacitor C1 is grounded to GND; the input terminal of the buffer is connected between the first resistor R1 and the first capacitor C1, and the output terminal of the buffer serves as the output terminal of the averaging unit 10.

[0030] The noise sampling unit 20 is connected to the power input terminal VDD and the averaging unit 10 respectively, so as to obtain the instantaneous value of the power supply voltage according to the input voltage, and obtain the noise signal according to the difference between the average value of the power supply voltage and the instantaneous value of the power supply voltage.

[0031] In other words, the noise sampling unit 20 calculates the difference between the average power supply voltage and the instantaneous power supply voltage, and transmits the difference to the integration unit for processing.

[0032] As an example, the sampling frequency of the noise sampling unit 20 is the output frequency of the voltage-controlled oscillator (VCO).

[0033] In one specific embodiment, the noise sampling unit 20 includes a first switch, a second switch, a third switch, a fourth switch, a second capacitor C2, a first NOT gate INV1, and a second NOT gate INV2. The input terminal of the first switch is connected to the power input terminal VDD. The input terminal of the second switch is connected to the output terminal of the first switch and has a first node B. The input terminal of the third switch is connected to the output terminal of the averaging unit 10. The input terminal of the fourth switch is connected to the output terminal of the third switch and has a second node C. One end of the second capacitor C2 is connected to the first node B, and the other end of the second capacitor C2 is connected to the second node C. The output terminal of the first NOT gate INV1 is connected to the control terminal of the first switch, and the input terminal of the first NOT gate INV1 is connected to the control terminal of the second switch. The output terminal of the second NOT gate INV2 is connected to the input terminal of the first NOT gate INV1, and the input terminal of the second NOT gate INV2 is connected to the output terminal OUTP of the voltage-controlled oscillator VCO.

[0034] In addition, the first switching transistor includes a first MOSFET Q1 and a second MOSFET Q2 connected to each other, the second switching transistor includes a third MOSFET Q5 and a fourth MOSFET Q6 connected to each other, the third switching transistor includes a fifth MOSFET Q3 and a sixth MOSFET Q4 connected to each other, and the fourth switching transistor includes a seventh MOSFET Q7 and an eighth MOSFET Q8 connected to each other.

[0035] It should be noted that the first NOT gate INV1 and the second NOT gate INV2 are used to control the opening and closing of the eight MOSFETs. When the output terminal OUTP of the voltage-controlled oscillator (VCO) outputs a high level, the first MOSFET Q1, the second MOSFET Q2, the fifth MOSFET Q3, and the sixth MOSFET Q4 are turned on, and the third MOSFET Q5, the fourth MOSFET Q6, the seventh MOSFET Q7, and the eighth MOSFET Q8 are turned off. At this time, electrical energy is stored in the second capacitor C2. When the output terminal OUTP of the VCO outputs a low level, the first MOSFET Q1, the second MOSFET Q2, the fifth MOSFET Q3, and the sixth MOSFET Q4 are turned off, and the third MOSFET Q5, the fourth MOSFET Q6, the seventh MOSFET Q7, and the eighth MOSFET Q8 are turned on. At this time, the noise signal is input to the integrator unit 30 for processing.

[0036] The integration unit 30 is connected to the noise sampling unit 20, and the integration unit 30 is used to process the noise signal to obtain the compensation signal.

[0037] It should be noted that the noise signal is power supply jitter.

[0038] In one specific embodiment, the integrator 30 includes a second resistor R2, a third capacitor C3, a third resistor R3, and an amplifier OPA. One end of the second resistor R2 is connected to the output terminal of the second switch transistor; one end of the third capacitor C3 is connected to the other end of the second resistor R2; the third resistor R3 and the third capacitor C3 are connected in parallel; the first input terminal of the amplifier OPA is connected between the second resistor R2 and the third capacitor C3; the second input terminal of the amplifier OPA is connected to the output terminal of the fourth switch transistor; the output terminal of the amplifier OPA is connected to the other end of the third capacitor C3; and the output terminal of the amplifier OPA serves as the output terminal of the integrator 30.

[0039] In other words, the power supply jitter is amplified by a certain proportion and then smoothed and filtered by the integration unit 30.

[0040] The proportional summing unit 40 is connected to the integral unit 30 so that the voltage control signal VCO_VCTRL of the voltage-controlled oscillator (VCO) can be obtained after supplementation with a compensation signal.

[0041] In other words, by adding the processed power supply jitter to the control voltage of the voltage-controlled oscillator (VCO), the power supply noise can be suppressed.

[0042] As an example, the output terminal of the proportional summing unit 40 is connected to the input terminal of the voltage-controlled oscillator (VCO), and the output terminal of the VCO is connected to the first input terminal of the noise sampling unit 20, so that the output frequency of the VCO is used as the sampling frequency of the noise sampling unit 20.

[0043] As a specific embodiment, the proportional summing unit 40 includes a fourth resistor R4 and a fifth resistor R5; one end of the fourth resistor R4 is connected to the output terminal of the amplifier OPA, and the other end of the fourth resistor R4 is connected to the input terminal of the voltage-controlled oscillator VCO; one end of the fifth resistor R5 is connected to the second input terminal of the amplifier OPA, and the other end of the fifth resistor R5 is connected to the input terminal of the voltage-controlled oscillator VCO.

[0044] It should be noted that by adjusting the values ​​of the fourth resistor R4 and the fifth resistor R5, the magnitude of the compensation signal is adjusted accordingly based on the magnitude of the voltage control signal VCTRL, thereby compensating for the voltage control signal VCTRL. This achieves power supply noise suppression for voltage-controlled oscillators with different power supply rejection ratios, resulting in not only good noise suppression but also easy on-chip integration. The signal waveform of the specific processing is shown below. Figure 3 and Figure 4 As shown.

[0045] In summary, the waveform of the output frequency change after control by the control voltage obtained using the power supply noise suppression circuit of the voltage-controlled oscillator of the present invention is shown in the figure below. Figure 5 As shown, it has an order-of-magnitude suppression effect on the output jitter of the voltage-controlled oscillator (VCO) caused by power supply noise. The power supply noise is generally 20-100mVpp. Assuming that the power supply noise contributes 80% to the total output jitter of the VCO, using a common operational amplifier with an offset of 1mV, it has a suppression effect of about 7dB on the total output jitter of the VCO; and a suppression effect of 8-34dB on jitter caused by power supply. Moreover, it does not require large capacitors and inductors and is easy to integrate.

[0046] In addition, such as Figure 6 As shown, an embodiment of the present invention also proposes an electronic device 1000, including a power supply noise suppression circuit 2000 for a voltage-controlled oscillator as described above.

[0047] The electronic device according to embodiments of the present invention can significantly suppress power noise by adjusting component parameters to achieve different power supply rejection ratios for voltage-controlled oscillators, thereby not only achieving good noise suppression but also being easy to integrate on-chip.

[0048] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0049] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0050] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; 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; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0051] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0052] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. The illustrative expressions of the above terms in this specification should not be construed as necessarily referring to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. In addition, those skilled in the art can combine and integrate the different embodiments or examples described in this specification.

[0053] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A power supply noise suppression circuit for a voltage-controlled oscillator, characterized in that, include: A power input terminal, which is used to provide an input voltage; A averaging unit is connected to the power input terminal, and the averaging unit obtains the average power supply voltage based on the input voltage; A noise sampling unit is connected to the power input terminal and the averaging unit respectively, so as to obtain the instantaneous value of the power supply voltage according to the input voltage, and obtain the noise signal according to the difference between the average value of the power supply voltage and the instantaneous value of the power supply voltage; An integration unit is connected to the noise sampling unit, and the integration unit is used to process the noise signal to obtain a compensation signal; A proportional summing unit is connected to the integral unit so that the voltage control signal of the voltage-controlled oscillator can be obtained after supplementation by the compensation signal; The noise sampling unit includes: The first switching transistor, the input terminal of which is connected to the power input terminal; The second switch has its input terminal connected to the output terminal of the first switch and has a first node; The third switch is connected to the output of the averaging unit. A fourth switch, the input terminal of which is connected to the output terminal of the third switch, and has a second node; A second capacitor, one end of which is connected to the first node, and the other end of which is connected to the second node; The first NOT gate has its output connected to the control terminal of the first switch, and its input connected to the control terminal of the second switch. The output of the second NOT gate is connected to the input of the first NOT gate, and the input of the second NOT gate is connected to the output of the voltage-controlled oscillator.

2. The power supply noise suppression circuit for the voltage-controlled oscillator according to claim 1, characterized in that, The sampling frequency of the noise sampling unit is the output frequency of the voltage-controlled oscillator.

3. The power supply noise suppression circuit for the voltage-controlled oscillator according to claim 2, characterized in that, The output terminal of the proportional summing unit is connected to the input terminal of the voltage-controlled oscillator, and the output terminal of the voltage-controlled oscillator is connected to the first input terminal of the noise sampling unit, so that the output frequency of the voltage-controlled oscillator is used as the sampling frequency of the noise sampling unit.

4. The power supply noise suppression circuit for the voltage-controlled oscillator according to claim 1, characterized in that, The mean unit includes: A first resistor, one end of which is connected to the power input terminal; A first capacitor, one end of which is connected to the other end of the first resistor, and the other end of the first capacitor is grounded; A buffer, the input of which is connected between the first resistor and the first capacitor, and the output of which serves as the output of the averaging unit.

5. The power supply noise suppression circuit for the voltage-controlled oscillator according to claim 1, characterized in that, The first switching transistor includes a first MOSFET and a second MOSFET connected to each other; the second switching transistor includes a third MOSFET and a fourth MOSFET connected to each other; the third switching transistor includes a fifth MOSFET and a sixth MOSFET connected to each other; and the fourth switching transistor includes a seventh MOSFET and an eighth MOSFET connected to each other.

6. The power supply noise suppression circuit for the voltage-controlled oscillator according to claim 1, characterized in that, The integration unit includes: The second resistor has one end connected to the output terminal of the second switching transistor; A third capacitor, one end of which is connected to the other end of the second resistor; The third resistor is connected in parallel with the third capacitor; An amplifier is provided, wherein the first input terminal of the amplifier is connected between the second resistor and the third capacitor, the second input terminal of the amplifier is connected to the output terminal of the fourth switching transistor, the output terminal of the amplifier is connected to the other end of the third capacitor, and the output terminal of the amplifier serves as the output terminal of the integration unit.

7. The power supply noise suppression circuit for the voltage-controlled oscillator according to claim 6, characterized in that, The proportional addition unit includes: A fourth resistor, one end of which is connected to the output terminal of the amplifier, and the other end of which is connected to the input terminal of the voltage-controlled oscillator; The fifth resistor has one end connected to the second input terminal of the amplifier and the other end connected to the input terminal of the voltage-controlled oscillator.

8. An electronic device, characterized in that, Includes a power supply noise suppression circuit for a voltage-controlled oscillator according to any one of claims 1-7.

Images