Capacitance multiplexing charge pump circuit and radio frequency switch module

Abstract

The invention relates to the technical field of wireless communication, and provides a capacitor multiplexing charge pump circuit and a radio frequency switch module, which comprise a sensor circuit, a first delay circuit, a second delay circuit, an oscillator, a charge pump, a first capacitor, a second capacitor, a first switch, a first load circuit, a second load circuit and a capacitor switching circuit, the output end of the oscillator is connected with the input end of the charge pump, the charge pump is connected with the first end of the first capacitor and the control end of the first switch, the output end of the first switch is connected to a first load circuit or a second load circuit, and the second end of the first capacitor is grounded; the output end of the capacitor switching circuit is used for being connected with the second capacitor in parallel and connected to the output end of the charge pump, and the capacitor switching circuit is connected to the second capacitor in parallel or connected to the output end of the charge pump according to the delay signal output by the second delay circuit and received by the capacitor switching circuit. According to the capacitor multiplexing charge pump circuit, the area and the overall complexity of the capacitor are reduced.

Description

Technical Field

[0001] The present invention relates to the field of wireless communication technology, and in particular to a capacitor multiplexing charge pump circuit and a radio frequency switch module. Background Art

[0002] RF switches are widely used in the RF front-end design of wireless communication devices. They can be used in various occasions where the on or off state of RF transmission signals needs to be effectively controlled, such as RF switches, receiving switches, channel selection switches, and antenna tuning switches. In RF switches, the electrical drive performance of RF switches is generally improved by using a charge pump circuit. The charge pump is a DC-DC converter that uses a capacitor as an energy storage element and is mostly used to generate an output voltage greater than the input voltage or a negative output voltage.

[0003] At present, the relevant RF switch includes a signal input terminal, a charge pump circuit, an output match, a switch and a signal output terminal which are electrically connected in sequence. The charge pump circuit includes a charge pump and multiple capacitors, and the multiple capacitors are used to provide power for the charge pump; the RF signal is connected through the signal input terminal, the RF signal is amplified and output to the output match through the charge pump, the output switch is matched after the output match, and the output of the signal is controlled by the switch to the load.

[0004] However, the above charges have too many capacitors, which results in an excessively large overall capacitor area, increasing the complexity of the circuit. Summary of the invention

[0005] In view of the above deficiencies in the prior art, the present invention proposes a capacitor multiplexing charge pump circuit and a radio frequency switch module to solve the problems of excessive capacitance, large capacitance area and complex circuit in the existing capacitor multiplexing charge pump circuit.

[0006] In order to solve the above technical problems, the present invention adopts the following technical solutions: In a first aspect, an embodiment of the present invention provides a capacitor multiplexing charge pump circuit, including a sensor circuit, a first delay circuit, a second delay circuit, an oscillator, a charge pump, a first capacitor, a second capacitor, a first switch, a first load circuit, a second load circuit, and a capacitor switching circuit; The input end of the sensor circuit is used to receive a control signal output by an external logic control circuit. The output end of the sensor circuit outputs a first signal and a second signal to the input end of the first delay circuit and the input end of the second delay circuit respectively. The output end of the first delay circuit is connected to the input end of the oscillator, the output end of the oscillator is connected to the input end of the charge pump, the ground end of the oscillator is grounded, and the output end of the charge pump is respectively connected to the first end of the first capacitor and the control end of the first switch. The control end of the first switch receives a control signal output by an external logic control circuit so that the output end of the first switch is used to connect to the first load circuit or the second load circuit, and the second end of the first capacitor is grounded; the second capacitor is used to provide charge for the charge pump; the input end of the capacitor switching circuit is used to receive a delay signal output by the second delay circuit, the output end of the capacitor switching circuit is used to be connected in parallel with the second capacitor and connected to the output end of the charge pump, and according to the delay signal output by the second delay circuit received by the capacitor switching circuit, the capacitor switching circuit is connected in parallel to the second capacitor or connected to the output end of the charge pump.

[0007] Preferably, the capacitor switching circuit includes a third capacitor, a second switch and a third switch; The first end of the third capacitor is connected to the control end of the second switch, the second end of the third capacitor is connected to the control end of the third switch, and the control end of the second switch and the control end of the third switch also serve as the input end of the capacitor switching circuit; the output end of the second switch is used to be grounded or connected to the first end of the third capacitor, the output end of the third switch is connected to the second end of the third capacitor or the output end of the charge pump, and the output end of the second switch and the output end of the third switch respectively serve as the output end of the capacitor switching circuit.

[0008] Preferably, when the second switch is grounded and the third switch is connected to the first end of the first capacitor, the capacitor multiplexing charge pump circuit operates in a steady state, and the total voltage stabilizing capacitor is the sum of the first capacitor and the third capacitor.

[0009] Preferably, when the control signal controls the switching of the first switch, a preset time is waited for the charge of the first capacitor to be replenished to the first load circuit or the second load circuit to reach the maximum excitation voltage; after the preset time, the output end of the second switch is connected to the first end of the second capacitor, and the output end of the third switch is connected to the second end of the second capacitor, so that the third capacitor is switched to the second capacitor.

[0010] Preferably, the driving capability of the charge pump is proportional to the product of the third capacitor and the vibration frequency of the oscillator.

[0011] Preferably, the first load circuit includes a fourth capacitor and a fourth switch; A first end of the fourth capacitor is connected to a first end of the fourth switch and to an output end of the first switch, and a second end of the fourth capacitor and a second end of the fourth switch are grounded, respectively.

[0012] Preferably, the second load circuit includes a fifth capacitor and a fifth switch; A first end of the fifth capacitor is connected to a first end of the fifth switch and to an output end of the first switch, and a second end of the fifth capacitor and a second end of the fifth switch are grounded, respectively.

[0013] In a second aspect, an embodiment of the present invention provides a radio frequency switch module, comprising the capacitor multiplexing charge pump circuit as described above. Compared with the related art, in an embodiment of the present invention, the input end of the sensor circuit is used to receive a control signal output by an external logic control circuit, and the output end of the sensor circuit outputs a first signal and a second signal to an input end of a first delay circuit and an input end of a second delay circuit respectively, the output end of the first delay circuit is connected to an input end of an oscillator, the output end of the oscillator is connected to an input end of a charge pump, the ground end of the oscillator is grounded, and the output end of the charge pump is respectively connected to a first end of a first capacitor and a control end of a first switch, and the control end of the first switch receives a control signal output by an external logic control circuit so that the output end of the first switch is connected to a first load circuit or a second load circuit, and the first capacitor The second end is grounded; the second capacitor is used to provide charge for the charge pump; the input end of the capacitor switching circuit is used to receive the delay signal output by the second delay circuit, the output end of the capacitor switching circuit is used to be connected in parallel with the second capacitor and to be connected to the output end of the charge pump, and according to the delay signal output by the second delay circuit received by the capacitor switching circuit, the capacitor switching circuit is connected in parallel to the second capacitor or connected to the output end of the charge pump; the corresponding capacitance size switching is performed through the first capacitor and the capacitor switching circuit, and applied to the first load circuit or the second load circuit, which can greatly reduce the circuit area of ​​the capacitor load and reduce the complexity of the overall circuit; at the same time, maintain a lower glitch voltage and a smaller setup time. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] The present invention will be described in detail below in conjunction with the accompanying drawings. The above and other aspects of the present invention will become clearer and easier to understand through the detailed description made in conjunction with the following drawings. In the accompanying drawings: Figure 1 A circuit structure block diagram of a capacitor multiplexing charge pump circuit provided in an embodiment of the present invention; Figure 2 A waveform diagram of a capacitor multiplexing charge pump circuit provided in an embodiment of the present invention.

[0015] Among them, 100, capacitor multiplexing charge pump circuit, 1, sensor circuit, 2, first delay circuit, 3, second delay circuit, 4, oscillator, 5, charge pump, 6, first load circuit, 7, second load circuit, 8, capacitor switching circuit. DETAILED DESCRIPTION Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by technicians in the technical field of the present application; the terms used in the specification of the application herein are only for the purpose of describing specific embodiments and are not intended to limit the present application; the terms "including" and "having" and any variations thereof in the specification and claims of the present application and the above-mentioned drawings are intended to cover non-exclusive inclusions. The terms "first", "second", etc. in the specification and claims of the present application or the above-mentioned drawings are used to distinguish different objects, not to describe a specific order.

[0016] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0017] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0018] Embodiment 1 See also Figure 1 As shown, an embodiment of the present invention provides a capacitor multiplexing charge pump circuit 100, including a sensor circuit 1, a first delay circuit 2, a second delay circuit 3, an oscillator 4, a charge pump 5, a first capacitor CS, a second capacitor CT, a first switch DS1, a first load circuit 6, a second load circuit 7 and a capacitor switching circuit 8.

[0019] The input end of the sensor circuit 1 is used to receive a control signal output by an external logic control circuit (not shown in the figure), and the output end of the sensor circuit 1 outputs a first signal and a second signal to the input end of the first delay circuit 2 and the input end of the second delay circuit 3 respectively. The output end of the first delay circuit 2 is connected to the input end of the oscillator 4, and the output end of the oscillator 4 is connected to the input end of the charge pump 5. The ground end of the oscillator 4 is grounded, and the output end of the charge pump 5 is respectively connected to the first end of the first capacitor CS and the control end of the first switch DS1. The control end of the first switch DS1 receives the control signal output by the external logic control circuit. The output end of the first switch DS1 is used to connect to the first load circuit 6 or the second load circuit 7, and the second end of the first capacitor CS is grounded; the second capacitor CT is used to provide charge for the charge pump 5; the input end of the capacitor switching circuit 8 is used to receive the delay signal output by the second delay circuit 3, and the output end of the capacitor switching circuit 8 is used to be connected in parallel with the second capacitor CT and connected to the output end of the charge pump 5, and according to the delay signal output by the second delay circuit 3 received by the capacitor switching circuit 8, the capacitor switching circuit 8 is connected in parallel to the second capacitor CT or connected to the output end of the charge pump 5. Optionally, the external logic control circuit can be a controller, etc.

[0020] Specifically, the control signal can control the first switch DS1 to switch to the first load circuit 6 or the second load circuit 7 through the external logic control circuit output to the sensor circuit 1 and the first switch DS1. The sensor circuit 1 is used to collect the control signal, and process the control signal to output different RF signals to the first delay circuit 2 and the second delay circuit 3. The first delay circuit 2 changes the RF signal within a specified time, prolongs the duration of the RF signal, and transmits the delayed RF signal to the oscillator 4, which is used to generate a stable frequency signal through the oscillator 4, and sends the stable frequency signal to the charge pump 5, which drives the signal to output to the first switch DS1 through the charge pump 5. The second delay circuit 3 changes the RF signal within a specified time, prolongs the duration of the RF signal, and transmits the delayed RF signal to the capacitor switching circuit 8, which controls the capacitor switching circuit 8 to switch to parallel with the first capacitor CS or the second capacitor CT to adjust the output of different capacitance sizes. In this way, the corresponding capacitance size switching is performed through the first capacitor CS and the capacitor switching circuit 8, and applied to the first load circuit 6 or the second load circuit 7, which can greatly reduce the circuit area of ​​the capacitor load and reduce the complexity of the overall circuit; at the same time, maintain a lower glitch voltage and a smaller setup time.

[0021] In this embodiment, the capacitor switching circuit 8 includes a third capacitor CV, a second switch DS2 and a third switch DS3; the first end of the third capacitor CV is connected to the control end of the second switch DS2, the second end of the third capacitor CV is connected to the control end of the third switch DS3, and the control end of the second switch DS2 and the control end of the third switch DS3 are also respectively used as the input end of the capacitor switching circuit 8; the output end of the second switch DS2 is used to be grounded or connected to the first end of the third capacitor CV, the output end of the third switch DS3 is connected to the second end of the third capacitor CV or the output end of the charge pump 5, and the output end of the second switch DS2 and the output end of the third switch DS3 are respectively used as the output end of the capacitor switching circuit 8. In this embodiment, Figure 2 As shown, when the second switch DS2 is grounded and the third switch DS3 is connected to the first end of the first capacitor CS, the capacitor multiplexing charge pump circuit 100 operates in a steady state, and the total voltage stabilizing capacitance is the sum of the first capacitor CS and the third capacitor CV. Therefore, after the charge of the first capacitor CS is transferred, the driving capability of the charge pump 5 needs to be strong enough to make the duration of the burr as short as possible, so that the second capacitor CT is large enough.

[0022] In this embodiment, when the control signal controls the switching of the first switch DS1, a preset time is given to allow the charge of the first capacitor CS to be supplemented to the first load circuit 6 or the second load circuit 7 to reach the maximum excitation voltage (Vspur); after the preset time, the output end of the second switch DS2 is connected to the first end of the second capacitor CT, and the output end of the third switch DS3 is connected to the second end of the second capacitor CT, so that the third capacitor CV is switched to the second capacitor CT. This can speed up the establishment of the output voltage (Vhold), and after the output voltage is stable, the third capacitor CV is switched to the first capacitor CS; this can greatly reduce the area of ​​the capacitor, while maintaining a lower glitch voltage and a smaller establishment time.

[0023] In this embodiment, the driving capability of the charge pump 5 is proportional to the product of the third capacitor CV and the vibration frequency of the oscillator 4 .

[0024] In this embodiment, the first load circuit 6 includes a fourth capacitor CL1 and a fourth switch SH1; the first end of the fourth capacitor CL1 is connected to the first end of the fourth switch SH1 and to the output end of the first switch DS1, and the second end of the fourth capacitor CL1 and the second end of the fourth switch SH1 are grounded respectively. For the charge pump 5 with capacitive load, when the load is switched, since the charge of the first capacitor CS is transferred to the fourth capacitor CL1, the output voltage will generate a glitch (Vhold-Vspur) at the switching moment, and the noise or interference introduced by the load should be minimized as much as possible during the non-switching process.

[0025] In this embodiment, the second load circuit 7 includes a fifth capacitor CL2 and a fifth switch SH2; the first end of the fifth capacitor CL2 is connected to the first end of the fifth switch SH2 and connected to the output end of the first switch DS1, and the second end of the fifth capacitor CL2 and the second end of the fifth switch SH2 are grounded respectively. When the load is switched, since the charge of the first capacitor CS is transferred to the fifth capacitor CL2, the output voltage will generate burrs at the switching moment, and the noise or interference introduced by the load should be minimized as much as possible during the non-switching process.

[0026] Embodiment 2 The embodiment of the present invention provides a radio frequency switch module, including the above-mentioned capacitor multiplexing charge pump circuit 100. The technical effect produced by the radio frequency switch module is the same as that of the above-mentioned capacitor multiplexing charge pump circuit 100, and will not be described here.

[0027] It should be noted that the various embodiments described above with reference to the accompanying drawings are only used to illustrate the present invention rather than to limit the scope of the present invention. Those skilled in the art should understand that any modification or equivalent substitution of the present invention without departing from the spirit and scope of the present invention should be included within the scope of the present invention. In addition, unless otherwise indicated by the context, words appearing in the singular include the plural form, and vice versa. In addition, unless otherwise specified, all or part of any embodiment may be used in combination with all or part of any other embodiment.

Claims

1. A capacitor multiplexing charge pump circuit, characterized in that: It includes a sensor circuit, a first delay circuit, a second delay circuit, an oscillator, a charge pump, a first capacitor, a second capacitor, a first switch, a first load circuit, a second load circuit and a capacitor switching circuit; The input end of the sensor circuit is used to receive a control signal output by an external logic control circuit. The output end of the sensor circuit outputs a first signal and a second signal to the input end of the first delay circuit and the input end of the second delay circuit respectively. The output end of the first delay circuit is connected to the input end of the oscillator, the output end of the oscillator is connected to the input end of the charge pump, the ground end of the oscillator is grounded, and the output end of the charge pump is respectively connected to the first end of the first capacitor and the control end of the first switch. The control end of the first switch receives a control signal output by an external logic control circuit so that the output end of the first switch is used to connect to the first load circuit or the second load circuit, and the second end of the first capacitor is grounded; the second capacitor is used to provide charge for the charge pump; the input end of the capacitor switching circuit is used to receive a delay signal output by the second delay circuit, the output end of the capacitor switching circuit is used to be connected in parallel with the second capacitor and connected to the output end of the charge pump, and according to the delay signal output by the second delay circuit received by the capacitor switching circuit, the capacitor switching circuit is connected in parallel to the second capacitor or connected to the output end of the charge pump.

2. The capacitor multiplexing charge pump circuit according to claim 1, characterized in that: The capacitor switching circuit includes a third capacitor, a second switch and a third switch; The first end of the third capacitor is connected to the control end of the second switch, the second end of the third capacitor is connected to the control end of the third switch, and the control end of the second switch and the control end of the third switch also serve as the input end of the capacitor switching circuit; the output end of the second switch is used to be grounded or connected to the first end of the third capacitor, the output end of the third switch is connected to the second end of the third capacitor or the output end of the charge pump, and the output end of the second switch and the output end of the third switch respectively serve as the output end of the capacitor switching circuit.

3. The capacitor multiplexing charge pump circuit according to claim 2, characterized in that: When the second switch is grounded and the third switch is connected to the first end of the first capacitor, the capacitor multiplexing charge pump circuit operates in a steady state, and the total voltage stabilizing capacitor is the sum of the first capacitor and the third capacitor.

4. The capacitor multiplexing charge pump circuit according to claim 2, characterized in that: When the control signal controls the switching of the first switch, wait for a preset time so that the charge of the first capacitor is replenished to the first load circuit or the second load circuit to reach the maximum excitation voltage; after the preset time, the output end of the second switch is connected to the first end of the second capacitor, and the output end of the third switch is connected to the second end of the second capacitor, so that the third capacitor is switched to the second capacitor.

5. The capacitor multiplexing charge pump circuit according to claim 2, characterized in that: The driving capability of the charge pump is proportional to the product of the third capacitor and the vibration frequency of the oscillator.

6. The capacitor multiplexing charge pump circuit according to claim 1, characterized in that: The first load circuit includes a fourth capacitor and a fourth switch; A first end of the fourth capacitor is connected to a first end of the fourth switch and to an output end of the first switch, and a second end of the fourth capacitor and a second end of the fourth switch are grounded, respectively.

7. The capacitor multiplexing charge pump circuit according to claim 1, characterized in that: The second load circuit includes a fifth capacitor and a fifth switch; A first end of the fifth capacitor is connected to a first end of the fifth switch and to an output end of the first switch, and a second end of the fifth capacitor and a second end of the fifth switch are grounded, respectively.

8. A radio frequency switch module, characterized in that: It comprises a capacitor multiplexing charge pump circuit as described in any one of claims 1 to 7.

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