CN219164553U - Filter, phase-locked loop and electronic equipment - Google Patents
Filter, phase-locked loop and electronic equipment Download PDFInfo
- Publication number
- CN219164553U CN219164553U CN202223137499.XU CN202223137499U CN219164553U CN 219164553 U CN219164553 U CN 219164553U CN 202223137499 U CN202223137499 U CN 202223137499U CN 219164553 U CN219164553 U CN 219164553U
- Authority
- CN
- China
- Prior art keywords
- filter circuit
- filter
- sub
- circuit
- negative feedback
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Landscapes
- Stabilization Of Oscillater, Synchronisation, Frequency Synthesizers (AREA)
Abstract
The application discloses a filter, a phase-locked loop and electronic equipment. The filter includes: a filter circuit and a negative feedback circuit. The filter circuit is connected with the charge pump and used for converting a current pulse signal generated by the charge pump into a loop control voltage signal; the negative feedback circuit is connected with the filter circuit and used for carrying out negative feedback adjustment on an intermediate electric signal, a loop control voltage signal or a current pulse signal of the filter circuit. The filter circuit comprises at least two stages of sub-filter circuits, a first stage of sub-filter circuit in the at least two stages of sub-filter circuits is used for being connected with the charge pump, and the negative feedback circuit is respectively connected with the two stages of sub-filter circuits and used for carrying out negative feedback adjustment on an intermediate electric signal output by the first stage of sub-filter circuit so as to reduce fluctuation of a loop control voltage signal output by a second stage of sub-filter circuit in the two stages of sub-filter circuits. The fluctuation of the loop control voltage signal can be reduced through the negative feedback regulation of the negative feedback circuit, so that the effect of reducing the fractional spurious amplitude is achieved.
Description
Technical Field
The present disclosure relates to the field of filters, and in particular, to a filter, a phase-locked loop, and an electronic device.
Background
Fractional spur is an inherent characteristic of fractional-n phase locked loops. When the fractional spurious amplitude is too large, some indexes such as adjacent channel power ratio (Adjacent Channel Power Rat io, ACPR), ACS, blocking and the like are affected, and when spurious points are close to an audio signal, howling is caused, so that the fractional spurious optimization is of practical significance.
Disclosure of Invention
The application provides a filter, a phase-locked loop and electronic equipment, which are used for solving the technical problems.
In order to solve the technical problems, the technical scheme adopted by the application is as follows: there is provided a filter, comprising: a filter circuit and a negative feedback circuit. The filter circuit is connected with the charge pump and used for converting a current pulse signal generated by the charge pump into a loop control voltage signal; the negative feedback circuit is connected with the filter circuit and used for carrying out negative feedback adjustment on an intermediate electric signal, a loop control voltage signal or a current pulse signal of the filter circuit so as to reduce fluctuation of the loop control voltage signal; when the negative feedback circuit is used for carrying out negative feedback adjustment on the intermediate electric signal of the filter circuit, the filter circuit comprises at least two stages of sub-filter circuits, a first stage of sub-filter circuit in the at least two stages of sub-filter circuits is used for being connected with the charge pump, and the negative feedback circuit is respectively connected with the two stages of sub-filter circuits and used for carrying out negative feedback adjustment on the intermediate electric signal output by the first stage of sub-filter circuit so as to reduce fluctuation of a loop control voltage signal output by a second stage of sub-filter circuit in the two stages of sub-filter circuits.
Wherein, negative feedback circuit includes: the input end of the switching tube is used for being connected with the power supply voltage, the control end of the switching tube is connected with the input end of the first-stage sub-filter circuit, and the output end of the switching tube or the input end of the switching tube is connected with the input end of the second-stage sub-filter circuit; the first end of the first resistor is connected with the output end of the switch tube, and the second end of the first resistor is grounded; and the first end of the second resistor is connected with the input end of the switching tube, and the second end of the second resistor is connected with the control end of the switching tube.
Wherein the negative feedback circuit further comprises: and the first end of the third resistor is connected with the control end of the switching tube, and the second end of the third resistor is grounded.
The filter circuit further comprises a third-stage sub-filter circuit to form a third-stage sub-filter circuit; the input end of the third stage sub-filter circuit is connected with the input end of the second stage sub-filter circuit.
The filter circuit further comprises a third-stage sub-filter circuit to form a third-stage sub-filter circuit; the input end of the third stage sub-filter circuit is connected with the control end of the switching tube.
Wherein a first stage of the three stage sub-filter circuit comprises: the first end of the first capacitor is used for being connected with the charge pump and the control end of the switch tube, and the second end of the first capacitor is grounded, wherein the first end of the first capacitor is used as the input end of the first-stage sub-filter circuit; the second stage sub-filter circuit includes: the first end of the fourth resistor is connected with the input end of the switching tube or the output end of the switching tube, and the second end of the fourth resistor is used as the output end of the second-stage sub-filter circuit to output a loop control voltage signal; the first end of the second capacitor is connected with the second end of the fourth resistor, and the second end of the second capacitor is grounded; the third stage sub-filter circuit includes: the first end of the fifth resistor is connected with the first end of the fourth resistor; and the first end of the third capacitor is connected with the second end of the fifth resistor, and the second end of the third capacitor is grounded.
Wherein a first stage of the three stage sub-filter circuit comprises: the first end of the first capacitor is used for being connected with the charge pump, and the second end of the first capacitor is grounded; the second stage sub-filter circuit includes: the first end of the fourth resistor is connected with the input end of the switching tube or the output end of the switching tube, and the second end of the fourth resistor is used as the output end of the second-stage sub-filter circuit to output a loop control voltage signal; the first end of the second capacitor is connected with the second end of the fourth resistor, and the second end of the second capacitor is grounded; the third stage sub-filter circuit includes: the first end of the fifth resistor is connected with the control end of the switching tube; and the first end of the third capacitor is connected with the second end of the fifth resistor, and the second end of the third capacitor is grounded.
The switching tube comprises a triode or a MOS tube.
In order to solve the technical problems, the technical scheme adopted by the application is as follows: there is provided a phase locked loop comprising a filter according to any of the embodiments described above.
In order to solve the technical problems, the technical scheme adopted by the application is as follows: there is provided an electronic device comprising a phase locked loop of any of the embodiments described above.
The beneficial effects of the embodiment of the application are that: there is provided a filter, comprising: a filter circuit and a negative feedback circuit. The filter circuit is connected with the charge pump and used for converting a current pulse signal generated by the charge pump into a loop control voltage signal; and the negative feedback circuit is connected with the filter circuit and is used for carrying out negative feedback adjustment on an intermediate electric signal, a loop control voltage signal or a current pulse signal of the filter circuit so as to reduce the fluctuation of the loop control voltage signal and further achieve the effect of reducing the decimal spurious amplitude.
Drawings
FIG. 1 is a schematic diagram of a first embodiment of a circuit configuration of a filter of the present application;
FIG. 2 is a schematic diagram of a second embodiment of a circuit configuration of the filter of the present application;
FIG. 3 is a schematic diagram of a first embodiment of a negative feedback circuit of the present application;
FIG. 4 is a schematic diagram of a second embodiment of a negative feedback circuit of the present application;
FIG. 5 is a schematic diagram of a third embodiment of a circuit configuration of the filter of the present application;
fig. 6 is a schematic diagram of a fourth embodiment of a circuit configuration of the filter of the present application;
fig. 7 is a schematic diagram of a fifth embodiment of a circuit configuration of the filter of the present application.
Detailed Description
The following description of the embodiments of the present application will be made clearly and fully with reference to the accompanying drawings, in which it is evident that the embodiments described are only some, but not all, of the embodiments of the present application. All other embodiments, which can be made by one of ordinary skill in the art without undue burden from the present disclosure, are within the scope of the present disclosure.
The terms "first," "second," and the like in this application are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. In the description of the present application, the meaning of "plurality" means at least two, for example, two, three, etc., unless specifically defined otherwise. Furthermore, the terms "comprising," "including," and "having," and any variations thereof, are intended to cover an exclusive inclusion. For example, a process, method, system, article, or apparatus that comprises a list of steps or elements is not limited to only those listed steps or elements but may include other steps or elements not listed or inherent to such process, method, article, or apparatus.
The present application provides a filter 10, as shown in fig. 1, fig. 1 is a schematic diagram of a first embodiment of a circuit configuration of the filter of the present application. Wherein the filter 10 comprises: the filter circuit 100 and the negative feedback circuit 200.
The filter circuit 100 is connected to the charge pump 20 for converting the current pulse signal lcp generated by the charge pump 20 into a loop control voltage signal CV.
The negative feedback circuit 200 is connected to the filter circuit 100, and is configured to perform negative feedback adjustment on the intermediate electric signal of the filter circuit 100, so as to reduce the fluctuation of the loop control voltage signal CV.
In other embodiments, a negative feedback circuit may be further disposed between the charge pump and the filter circuit, for performing negative feedback adjustment on the current pulse signal lcp output by the charge pump; or the negative feedback circuit can also be arranged at the output end of the filter circuit and used for carrying out negative feedback adjustment on the loop control voltage signal CV output by the filter circuit.
When the fractional pll is locked, the charge pump 20 still outputs the positive and negative current pulse signals lcp due to the switching of the frequency division ratio N/n+1, and the positive and negative current pulse signals lcp become fluctuations of the loop control voltage signal CV through the filter 10. In contrast to the prior art, the present application reduces the fluctuation of the loop control voltage signal CV by connecting the negative feedback circuit 200 at any one of the input end of the filter circuit 100 of the filter 10, the sub-filter circuits of each stage of the filter circuit 100, and the output end, so as to perform negative feedback adjustment on the intermediate electric signal, the loop control voltage signal CV, or the current pulse signal lcp of the filter circuit 100 by the negative feedback characteristic of the negative feedback circuit 200, thereby reducing the fractional spurious amplitude.
Specifically, the filter circuit 100 includes at least two stages of sub-filter circuits. As shown in fig. 2, fig. 2 is a schematic diagram of a second embodiment of a circuit configuration of the filter of the present application.
Wherein the two-stage sub-filter circuit comprises: a first stage sub-filter circuit and a second stage sub-filter circuit.
A first end of a first stage of the two stage sub-filter circuit is connected with the charge pump 20, and a second end of the first stage of the two stage sub-filter circuit is grounded, wherein the first end of the first stage of the two stage sub-filter circuit is an input end of the first stage of the sub-filter circuit.
The negative feedback circuit 200 includes a control terminal B, an input terminal C, and an output terminal E. The negative feedback circuit 200 is respectively connected with two stages of sub-filter circuits, specifically, a control end B of the negative feedback circuit 200 is connected with a first end of a first stage sub-filter circuit in the two stages of sub-filter circuits, an input end C of the negative feedback circuit is connected with a power supply voltage Vcc, and an output end E of the negative feedback circuit is connected with a first end of a second stage sub-filter circuit in the two stages of sub-filter circuits, and is used for performing negative feedback adjustment on an intermediate electric signal output by the first stage sub-filter circuit so as to reduce fluctuation of a loop control voltage signal CV output by the second stage sub-filter circuit in the two stages of sub-filter circuits. In other embodiments, the first terminal of the second stage sub-filter circuit may also be connected to the input terminal C.
The second stage of the two stage sub-filter circuit is grounded at its second terminal and its output terminal is used as the output terminal of the filter 10 for outputting the loop control voltage signal CV.
The first end of the second stage sub-filter circuit in the two stages of sub-filter circuits is the input end of the second stage sub-filter circuit in the two stages of sub-filter circuits.
Alternatively, as shown in fig. 3, fig. 3 is a schematic diagram of a first embodiment of the negative feedback circuit of the present application. The negative feedback circuit 200 includes: a switching tube (not shown), a first resistor R1 and a second resistor R2.
The input terminal of the switching tube is used as the input terminal C of the negative feedback circuit 200 for accessing the power supply voltage Vcc. The control end of the switching tube is used as the control end B of the negative feedback circuit 200 and is connected with the first end of the first stage sub-filter circuit, and the output end of the switching tube is used as the output end E of the negative feedback circuit 200.
The first end of the first resistor R1 is connected with the output end of the switching tube, and the second end of the first resistor R1 is grounded and is used for converting current change of the output end of the switching tube into voltage change.
The first end of the second resistor R2 is connected with the input end of the switching tube, and the second end of the second resistor R2 is connected with the control end of the switching tube.
The switching tube is a triode, wherein an Emitter (Emitter), a Base (Base) and a collector (collector) in the triode are respectively used as an output end, a control end and an input end of the middle switching tube. The transistor forms a negative feedback circuit 200 having a negative feedback characteristic by the above-described circuit arrangement. Specifically, when the charge pump 20 outputs the positive current pulse signal lcp, ib increases, ie also increases, and ve=ie·re also increases. Since Vb is substantially unchanged, vbe=vb-Ve becomes small, ie is reduced, and thus changes in Ie and Ve are suppressed, and the fluctuation of the current pulse signal lcp is reduced. When the charge pump 20 outputs the negative current pulse signal lcp, the principle is the same as that of the positive current pulse signal lcp, and will not be described herein.
Wherein Ib is a current flowing through the base electrode; ie is the current flowing through the emitter; ve is the voltage at the emitter; vb is the voltage at the base; vbe is the voltage difference between the base and emitter.
Optionally, the negative feedback circuit 200 further comprises a third resistor R3. The first end of the third resistor R3 is connected with the control end of the switching tube, and the second end of the third resistor R3 is grounded. The third resistor R3 is used to accelerate the formation of the breakdown voltage of the control terminal of the switching tube.
It should be noted that, in other embodiments, the third resistor R3 may not be disposed in the negative feedback circuit 200.
Alternatively, in other embodiments, the switching tube may also be a MOS tube, and specifically, see fig. 4, where fig. 4 is a schematic diagram of a second embodiment of the negative feedback circuit of the present application.
The only difference between the first embodiment of the negative feedback circuit 200 and the present embodiment is that in the present embodiment, the MOS transistor is used to replace the transistor. Specifically, the source of the MOS transistor is used as the output end E of the negative feedback circuit 200, the drain of the MOS transistor is used as the input end C of the negative feedback circuit 200, and the gate of the MOS transistor is used as the control end B of the negative feedback circuit 200.
Compared to the first embodiment of the negative feedback circuit 200, it has the above-mentioned negative feedback characteristics of the first embodiment of the negative feedback circuit 200, and also has the low noise characteristics of the MOS transistor.
Alternatively, as shown in fig. 5, fig. 5 is a schematic diagram of a third embodiment of a circuit structure of the filter of the present application. Unlike the above-described embodiment, in the present embodiment, the filter circuit 100 further includes a third stage sub-filter circuit to constitute a third stage sub-filter circuit. The input end of the third-stage sub-filter circuit is connected with the first end of the second-stage sub-filter circuit. The negative feedback circuit 200 is connected to a first stage sub-filter circuit of the three stage sub-filter circuits and a second stage sub-filter circuit of the three stage sub-filter circuits, respectively.
Specifically, a first end of a first stage sub-filter circuit in the three stage sub-filter circuit is connected with the charge pump 20 and is connected with a control end B of the negative feedback circuit 200, and a second end of the first stage sub-filter circuit in the three stage sub-filter circuit is grounded; the first end of the second stage sub-filter circuit of the three stage sub-filter circuit is connected to the output end E of the negative feedback circuit 200 and to the first end of the third stage sub-filter circuit of the three stage sub-filter circuit, wherein the output end of the second stage sub-filter circuit of the three stage sub-filter circuit is used as the output end of the filter 10 for outputting the loop control voltage signal CV.
In this embodiment, a first stage sub-filter circuit of the three stage sub-filter circuit includes a first capacitor C1. The first end of the first capacitor C1 is used as the first end of the first stage sub-filter circuit in the three stage sub-filter circuit and the input end of the first stage sub-filter circuit, and is used for being connected with the charge pump 20 and the control end B of the switch tube, and the second end of the first capacitor C1 is the second end of the first stage sub-filter circuit in the three stage sub-filter circuit and is used for being grounded.
The second stage sub-filter circuit of the three stage sub-filter circuit includes: fourth resistor R4 and second capacitor C2. The first end of the fourth resistor R4 is the first end of a second-stage sub-filter circuit in the three-stage sub-filter circuit, is connected with the output end of the switching tube, and the second end of the fourth resistor R4 is used as the output end of the second-stage sub-filter circuit to output a loop control voltage signal CV; the first end of the second capacitor C2 is connected to the second end of the fourth resistor R4, and the second end of the second capacitor C2 is grounded.
The third stage sub-filter circuit of the three stage sub-filter circuit includes: fifth resistor R5 and third capacitor C3. The first end of the fifth resistor R5 is used as the first end of a third stage sub-filter circuit in the third stage sub-filter circuit and is connected with the first end of the fourth resistor R4; the first end of the third capacitor C3 is connected to the second end of the fifth resistor R5, and the second end of the third capacitor C3 is grounded.
In this embodiment, the negative feedback circuit 200 is a first embodiment of the negative feedback circuit 200, and in other embodiments, the negative feedback circuit 200 may be replaced by the above-mentioned second embodiment of the negative feedback circuit 200 based on the filtering circuit 100 of this embodiment, which is not described herein.
Alternatively, as shown in fig. 6, fig. 6 is a schematic diagram of a fourth embodiment of a circuit structure of the filter of the present application. The filter circuit 100 of this embodiment is similar to the third embodiment of the circuit structure of the filter 10 of the present application, and is a three-stage sub-filter circuit. The difference between the present embodiment and the third embodiment of the circuit structure of the filter 10 of the present application is that the negative feedback circuit 200 is connected to the second stage sub-filter circuit of the three stage sub-filter circuits and the third stage sub-filter circuit of the three stage sub-filter circuits, respectively, where the input end of the third stage sub-filter circuit is connected to the control end of the switching tube.
Specifically, a first end of a first stage of sub-filter circuit in the three stages of sub-filter circuits is connected with the charge pump 20, and a second end of the first stage of sub-filter circuit in the three stages of sub-filter circuits is grounded; the first end of the third stage sub-filter circuit in the third stage sub-filter circuit, namely the input end of the third stage sub-filter circuit, is connected with the control end B of the negative feedback circuit 200 and is connected with the first end of the first stage sub-filter circuit in the third stage sub-filter circuit; the first end of the second stage sub-filter circuit in the three stage sub-filter circuit is connected to the output end E of the negative feedback circuit 200, wherein the output end of the second stage sub-filter circuit in the three stage sub-filter circuit is used as the output end of the filter 10 for outputting the loop control voltage signal CV.
In this embodiment, a first stage sub-filter circuit of the three stage sub-filter circuit includes a first capacitor C1. The first end of the first capacitor C1 is used as the first end of the first stage sub-filter circuit in the three stage sub-filter circuit and is used for being connected with the charge pump 20, and the second end of the first capacitor C1 is used as the second end of the first stage sub-filter circuit in the three stage sub-filter circuit and is used for being grounded.
The second stage sub-filter circuit of the three stage sub-filter circuit includes: fourth resistor R4 and second capacitor C2. The first end of the fourth resistor R4 is the first end of a second-stage sub-filter circuit in the three-stage sub-filter circuit, is connected with the output end of the switching tube, and the second end of the fourth resistor R4 is used as the output end of the second-stage sub-filter circuit to output a loop control voltage signal CV; the first end of the second capacitor C2 is connected to the second end of the fourth resistor R4, and the second end of the second capacitor C2 is grounded.
The third stage sub-filter circuit of the three stage sub-filter circuit includes: fifth resistor R5 and third capacitor C3. The first end of the fifth resistor R5 is used as the first end of a third-stage sub-filter circuit in the third-stage sub-filter circuit and is connected with the control end of the switching tube; the first end of the third capacitor C3 is connected to the second end of the fifth resistor R5, and the second end of the third capacitor C3 is grounded.
In this embodiment, the negative feedback circuit 200 is a first embodiment of the negative feedback circuit 200, and in other embodiments, the negative feedback circuit 200 may be replaced by the above-mentioned second embodiment of the negative feedback circuit 200 based on the filtering circuit 100 of this embodiment, which is not described herein.
Alternatively, as shown in fig. 7, fig. 7 is a schematic diagram of a fifth embodiment of a circuit configuration of the filter of the present application. The present embodiment is similar to the fourth embodiment of the circuit structure of the filter 10 of the present application, and the only difference is that in the present embodiment, the first end of the second stage sub-filter circuit in the three stage sub-filter circuit is connected to the input terminal C of the negative feedback circuit 200, that is, the first end of the second stage sub-filter circuit in the three stage sub-filter circuit is connected to the input terminal of the switching tube, so as to extend the range of the loop control voltage signal CV that is finally output. The other circuit connections of the filter 10 in this embodiment may be specifically described with reference to the above embodiments, and will not be described herein.
In this embodiment, the negative feedback circuit 200 is a first embodiment of the negative feedback circuit 200, and in other embodiments, the negative feedback circuit 200 may be replaced by the above-mentioned second embodiment of the negative feedback circuit 200 based on the filtering circuit 100 of this embodiment, which is not described herein.
Alternatively, in the above embodiments of the circuit configuration of the filter 10 of the present application, the method of the fifth embodiment of the circuit configuration of the filter 10 of the present application may be used to extend the range of the loop control voltage signal CV to be finally output. Specifically, in the above embodiment of the circuit structure of the filter 10 of the present application, the corresponding sub-filter circuit connected to the output terminal E of the negative feedback circuit 200 is switched to be connected to the input terminal C of the negative feedback circuit 200, so that the function of expanding the range of the loop control voltage signal CV finally output can be realized.
The present application also proposes a phase locked loop comprising the filter 10 of any of the embodiments described above.
The application also proposes an electronic device comprising a phase locked loop of any of the embodiments described above.
In summary, the present application reduces the fluctuation of the loop control voltage signal CV and further reduces the fractional spurious amplitude by connecting the negative feedback circuit 200 to any one of the input end of the filter circuit 100 of the filter 10, the sub-filter circuits of each stage of the filter circuit 100, and the output end, so as to perform negative feedback adjustment on the intermediate electric signal, the loop control voltage signal CV, or the current pulse signal lcp of the filter circuit 100 by the negative feedback characteristic of the negative feedback circuit 200. Further, the negative feedback circuit 200 may be flexibly disposed between each stage of sub-filter circuits in the filter circuit 100, so that the width range of the loop control voltage signal CV can be effectively increased or the locking time of the filter 10 can be shortened while ensuring that the negative feedback characteristic of the present application is used for stabilizing the loop control voltage signal CV.
It should be noted that the drawings herein are only for illustrating the structural relationship and the connection relationship of the inventive product of the present application, and are not limited to the specific structural dimensions of the inventive product of the present application.
The foregoing description is only of embodiments of the present utility model, and is not intended to limit the scope of the utility model, and all equivalent structures or equivalent processes using the descriptions and the drawings of the present utility model or directly or indirectly applied to other related technical fields are included in the scope of the present utility model.
Claims (10)
1. A filter, comprising:
the filter circuit is connected with the charge pump and used for converting a current pulse signal generated by the charge pump into a loop control voltage signal;
the negative feedback circuit is connected with the filter circuit and is used for carrying out negative feedback adjustment on the intermediate electric signal, the loop control voltage signal or the current pulse signal of the filter circuit so as to reduce fluctuation of the loop control voltage signal;
when the negative feedback circuit is used for carrying out negative feedback adjustment on the intermediate electric signal of the filter circuit, the filter circuit comprises at least two stages of sub-filter circuits, a first stage of sub-filter circuit in the at least two stages of sub-filter circuits is used for being connected with the charge pump, and the negative feedback circuit is respectively connected with the two stages of sub-filter circuits and is used for carrying out negative feedback adjustment on the intermediate electric signal output by the first stage of sub-filter circuit so as to reduce fluctuation of the loop control voltage signal output by a second stage of sub-filter circuit in the two stages of sub-filter circuits.
2. The filter of claim 1, wherein the negative feedback circuit comprises:
the input end of the switching tube is used for being connected with a power supply voltage, the control end of the switching tube is connected with the input end of the first-stage sub-filter circuit, and the input end of the switching tube or the output end of the switching tube is connected with the input end of the second-stage sub-filter circuit;
the first end of the first resistor is connected with the output end of the switch tube, and the second end of the first resistor is grounded;
the first end of the second resistor is connected with the input end of the switching tube, and the second end of the second resistor is connected with the control end of the switching tube.
3. The filter of claim 2, wherein the negative feedback circuit further comprises:
and the first end of the third resistor is connected with the control end of the switching tube, and the second end of the third resistor is grounded.
4. A filter according to claim 2 or 3, wherein the filter circuit further comprises a third stage sub-filter circuit to form a third stage sub-filter circuit; the input end of the third-stage sub-filter circuit is connected with the input end of the second-stage sub-filter circuit.
5. A filter according to claim 2 or 3, wherein the filter circuit further comprises a third stage sub-filter circuit to form a third stage sub-filter circuit; and the input end of the third-stage sub-filter circuit is connected with the control end of the switching tube.
6. The filter of claim 4, wherein the first stage sub-filter circuit comprises:
the first end of the first capacitor is used for being connected with the charge pump and the control end of the switch tube, and the second end of the first capacitor is grounded, wherein the first end of the first capacitor is used as the input end of the first stage sub-filter circuit;
the second stage sub-filter circuit includes:
the first end of the fourth resistor is connected with the input end of the switching tube or the output end of the switching tube, and the second end of the fourth resistor is used as the output end of the second-stage sub-filter circuit to output the loop control voltage signal;
the first end of the second capacitor is connected with the second end of the fourth resistor, and the second end of the second capacitor is grounded;
the third stage sub-filter circuit includes:
a fifth resistor, wherein a first end of the fifth resistor is connected with a first end of the fourth resistor;
and the first end of the third capacitor is connected with the second end of the fifth resistor, and the second end of the third capacitor is grounded.
7. The filter of claim 5, wherein the first stage sub-filter circuit comprises:
a first end of the first capacitor is used for being connected with the charge pump, and a second end of the first capacitor is grounded;
the second stage sub-filter circuit includes:
the first end of the fourth resistor is connected with the input end of the switching tube or the output end of the switching tube, and the second end of the fourth resistor is used as the output end of the second-stage sub-filter circuit to output the loop control voltage signal;
the first end of the second capacitor is connected with the second end of the fourth resistor, and the second end of the second capacitor is grounded;
the third stage sub-filter circuit includes:
the first end of the fifth resistor is connected with the control end of the switching tube;
and the first end of the third capacitor is connected with the second end of the fifth resistor, and the second end of the third capacitor is grounded.
8. The filter of claim 2, wherein the switching tube comprises a triode or a MOS tube.
9. A phase locked loop comprising a filter as claimed in any one of claims 1 to 8.
10. An electronic device comprising the phase locked loop of claim 9.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202223137499.XU CN219164553U (en) | 2022-11-24 | 2022-11-24 | Filter, phase-locked loop and electronic equipment |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202223137499.XU CN219164553U (en) | 2022-11-24 | 2022-11-24 | Filter, phase-locked loop and electronic equipment |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN219164553U true CN219164553U (en) | 2023-06-09 |
Family
ID=86616235
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202223137499.XU Active CN219164553U (en) | 2022-11-24 | 2022-11-24 | Filter, phase-locked loop and electronic equipment |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN219164553U (en) |
-
2022
- 2022-11-24 CN CN202223137499.XU patent/CN219164553U/en active Active
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Krummenacher et al. | A 4-MHz CMOS continuous-time filter with on-chip automatic tuning | |
| CN106877819B (en) | Voltage controlled oscillator based on composite resonator | |
| US4723110A (en) | Transconductance amplifier | |
| US20200127668A1 (en) | Phase locked loop | |
| Chen et al. | A 2V pp, 80-200MHz fourth-order continuous-time linear phase filter with automatic frequency tuning | |
| CN104426479A (en) | Low-power consumption, low-jitter, and wide working-range crystal oscillator circuit | |
| US11824543B2 (en) | Folded ramp generator | |
| US7394325B2 (en) | Voltage-controlled oscillator circuit and PLL circuit | |
| GB2415102A (en) | PLL circuit and frequency-setting circuit | |
| CN105406829A (en) | Variable gain amplifier with continuously adjustable gain | |
| CN104270147A (en) | Ring oscillator | |
| CN101483408B (en) | Passive frequency mixer | |
| CN219164553U (en) | Filter, phase-locked loop and electronic equipment | |
| US6529084B1 (en) | Interleaved feedforward VCO and PLL | |
| US9444439B2 (en) | Pulse generating circuit for audio-frequency amplifiers and regulated power supplies | |
| EP3512094B1 (en) | Filter networks for driving capacitive loads | |
| CN203504497U (en) | Low power consumption, low jittering, and wide work range crystal oscillator circuit | |
| CN216672986U (en) | Loop filter and analog phase-locked loop comprising same | |
| US20080238556A1 (en) | Simple Technique For Reduction Of Gain In A Voltage Controlled Oscillator | |
| CN105577171A (en) | Circuit structure for phase-locked loop | |
| EP2773041A1 (en) | A two stage source-follower based filter | |
| CN104518784A (en) | Phase locked loop circuit | |
| KR19990008229A (en) | Frequency dependent resistors | |
| CN110311674B (en) | Control method and circuit for suppressing spurious output clock of phase-locked loop | |
| JP2022041515A (en) | Semiconductor circuit |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| GR01 | Patent grant | ||
| GR01 | Patent grant |