Charge Pump Circuit

Abstract

Embodiments of the present disclosure relate to a charge pump circuit. A charge pump circuit is provided, comprising: a detection feedback stage, a voltage input terminal and a voltage output terminal are connected to the detection feedback stage, and the feedback output terminal of the detection feedback stage generates a feedback voltage based on the output voltage from the voltage output terminal and the input voltage of the voltage input terminal; an error amplifier stage, the feedback output terminal is connected to the first input terminal of the error amplifier stage, so that the feedback voltage is input to the error amplifier stage, the second input terminal of the error amplifier stage receives a reference voltage signal, and the error amplifier stage also includes an amplification output terminal for outputting a voltage signal; and a charge pump stage, the charge pump stage includes a charge pump unit, the charge pump unit is connected to the voltage input terminal, the input voltage of the voltage input terminal is converted and output from the voltage output terminal, and the charge pump stage is also connected to the amplification output terminal, and is used to adjust the voltage conversion amplitude according to the voltage signal output by the error amplifier stage.

Description

Technical Field

[0001] Embodiments of the present disclosure relate to charge pump circuits. Background Art

[0002] A charge pump is a switching converter that uses capacitors to store energy, wherein switches are used to switch the capacitors between supply and discharge states, thereby increasing or decreasing the supply voltage.

[0003] Charge pumps are widely used in circuit design. For example, charge pumps can be used in power supply and storage products. In power supply applications, the input voltage and load current of the charge pump usually have a large range of variation. The voltage can range from a few volts to tens of volts or even hundreds of volts, and the load current can range from tens of microamperes to a few milliamperes or even tens of milliamperes. This poses a great challenge to the design of charge pump circuits in power supply products.

[0004] The charge pump circuit in the prior art is an open loop, which has two input voltages. During operation, by opening and closing a plurality of switches, the charge pump can theoretically convert the output voltage to the voltage of the sum of the two input voltages. However, in actual operation, the range of the input voltage is very large. In this case, the higher the input voltage, the greater the parasitic capacitance generated in the nodes of the charge pump, which results in greater efficiency loss. Therefore, the output voltage of such an open loop charge pump circuit in the prior art is greatly different from the theoretical value, and the power consumption of each node in the circuit is very large.

[0005] Moreover, the open-loop charge pump circuit of the prior art is not suitable for cascading, because a large parasitic capacitance will be generated on the relevant nodes of the second stage, which will greatly deteriorate the efficiency of the charge pump. Although the parasitic capacitance can be reduced by adding components such as MOS tubes, in the open-loop charge pump circuit, the driving voltage of the MOS tube will significantly reduce the boosting ability of the charge pump, especially when the input voltage is low. This effect is more obvious. Moreover, when the charge pump circuit of the prior art requires a higher boost, it is necessary to use high-voltage resistant switches and capacitors, which greatly increases the area cost.

[0006] Therefore, it is desirable to provide a charge pump circuit that can have good voltage boosting capability when the input voltage is low and has low power consumption and area overhead when the input voltage and load vary over a wide range. Summary of the invention

[0007] This Summary is provided to introduce a selection of concepts in a simplified form that are further described in the Detailed Description below. This Summary is not intended to identify key features or essential features of the disclosure, nor is it intended to limit the scope of the disclosure.

[0008] According to an embodiment of the present disclosure, a charge pump circuit is provided, comprising: a detection feedback stage, a voltage input terminal and a voltage output terminal are connected to the detection feedback stage, and the feedback output terminal of the detection feedback stage generates a feedback voltage based on the output voltage from the voltage output terminal and the input voltage of the voltage input terminal; an error amplifier stage, the feedback output terminal is connected to the first input terminal of the error amplifier stage, so that the feedback voltage is input to the error amplifier stage, the second input terminal of the error amplifier stage receives a reference voltage signal, and the error amplifier stage also includes an amplification output terminal for outputting a voltage signal; and a charge pump stage, the charge pump stage includes a charge pump unit, the charge pump unit is connected to the voltage input terminal, converts the input voltage of the voltage input terminal and outputs it from the voltage output terminal, and the charge pump stage is also connected to the amplification output terminal, and is used to adjust the voltage conversion amplitude according to the voltage signal output by the error amplifier stage. Through the above technical solution, the output signal of the charge pump circuit can be fed back to the input terminal in real time, so that in a closed-loop charge pump circuit, the voltage and current in the circuit can be adjusted in real time according to the feedback result through circuit design, thereby achieving the advantages of improving the performance and stability of the circuit.

[0009] According to an embodiment of the present disclosure, the detection feedback stage includes a voltage difference detection unit and a feedback network. The voltage difference detection unit obtains a voltage difference based on the output voltage and the input voltage and generates the feedback voltage through the feedback network.

[0010] According to an embodiment of the present disclosure, the charge pump stage includes a first power tube, a first pole or a second pole of the first power tube is connected to the charge pump unit, and a control end of the first power tube receives a voltage signal output by an amplified output end of the error amplifier stage, wherein a current flowing through the first power tube changes with a change in the voltage signal output by the amplified output end.

[0011] According to an embodiment of the present disclosure, the charge pump circuit further includes a buffer stage between the error amplifier stage and the charge pump stage, the amplifier output end is connected to the buffer stage, and the buffer output end of the buffer stage is connected to the control end of the first power tube.

[0012] According to an embodiment of the present disclosure, the buffer stage includes a second power tube and a third power tube, the control end of the second power tube is connected to the control end of the first power tube of the charge pump stage, the first pole of the second power tube is connected to the first pole of the third power tube and to the control end of the second power tube, the second pole of the second power tube is connected to a reference potential, the control end of the third power tube is connected to the output end of the error amplifier stage and receives a voltage signal from the error amplifier stage, the first pole of the third power tube is connected to the first pole of the second power tube and to the control end of the second power tube, and the second pole of the third power tube is connected to an operating voltage.

[0013] According to an embodiment of the present disclosure, the detection feedback stage includes a fourth power tube, a fifth power tube, a first resistor, and a second resistor, the voltage input end is connected to the second pole of the fourth power tube, the control end of the fourth power tube is connected to the control end of the fifth power tube and to the first pole of the fourth power tube, the first pole of the fourth power tube is connected to one end of the first resistor and connected to a reference potential, the voltage output end is connected to one end of the second resistor, the other end of the second resistor is connected to the second pole of the fifth power tube, the control end of the fifth power tube is connected to the control end of the fourth power tube, and the first pole of the fifth power tube is connected to the other end of the first resistor and to the first input end of the error amplifier stage.

[0014] According to an embodiment of the present disclosure, the charge pump stage includes a first power tube, a first capacitor, a first switch, a second switch, a third switch, and a fourth switch, the node at one end of the first capacitor is respectively connected to the input voltage through the first switch and to the output voltage through the fourth switch, the node at the other end of the first capacitor is respectively connected to the input voltage through the third switch and to the first pole of the first power tube through the second switch, and the second pole of the first power tube is connected to the reference potential.

[0015] According to an embodiment of the present disclosure, the charge pump stage includes N charge pump units, and the N charge pump units are connected to form an N-phase charge pump structure, where N is a positive integer.

[0016] According to an embodiment of the present disclosure, the charge pump stage includes a first power tube, a first capacitor, a second capacitor, a first switch, a second switch, a third switch, a fourth switch, a fifth switch, a sixth switch, a seventh switch, and an eighth switch. The nodes at one end of the first capacitor are respectively connected to the input voltage through the first switch and to the output voltage through the fourth switch. The nodes at the other end of the first capacitor are respectively connected to the input voltage through the third switch and to the first pole of the first power tube through the second switch. The nodes at one end of the second capacitor are respectively connected to the input voltage through the fifth switch and to the output voltage through the eighth switch. The nodes at the other end of the second capacitor are respectively connected to the input voltage through the seventh switch and to the first pole of the first power tube through the sixth switch. The second pole of the first power tube is connected to the reference potential. The control end of the first power tube is connected to the amplified output end.

[0017] According to an embodiment of the present disclosure, the charge pump stage includes a plurality of charge pump units, and the plurality of charge pump units are cascaded.

[0018] According to an embodiment of the present disclosure, the charge pump stage includes a first power tube, a first capacitor, a second capacitor, a first switch, a second switch, a third switch, a fourth switch, a fifth switch, a sixth switch, a seventh switch, and an eighth switch. The nodes at one end of the first capacitor are respectively connected to the input voltage through the first switch and to the next-stage charge pump unit through the fourth switch. The nodes at the other end of the first capacitor are respectively connected to the input voltage through the third switch and to the first pole of the first power tube through the second switch. The nodes at one end of the second capacitor are respectively connected to the first stage through the fifth switch and to the output voltage through the eighth switch. The nodes at the other end of the second capacitor are respectively connected to the previous-stage charge pump unit through the seventh switch and to the first pole of the first power tube through the sixth switch. The second pole of the first power tube is connected to the reference potential.

[0019] According to an embodiment of the present disclosure, a charge pump circuit is provided, comprising: a detection feedback stage, a voltage output terminal is connected to the detection feedback stage, and the feedback output terminal of the detection feedback stage generates a feedback voltage based on the output voltage from the voltage output terminal and a reference potential; an error amplifier stage, the feedback output terminal is connected to the first input terminal of the error amplifier stage, so that the feedback voltage is input to the error amplifier stage, the second input terminal of the error amplifier stage receives a reference voltage signal, and the error amplifier stage also includes an amplified output terminal for outputting a voltage signal; a buffer stage, the buffer stage is located between the error amplifier stage and the charge pump stage, the amplified output terminal is connected to the buffer stage, and the buffer output terminal of the buffer stage is connected to the charge pump stage; and a charge pump stage, the charge pump stage includes a charge pump unit, the charge pump unit is connected to the voltage output terminal for changing the voltage and outputting it from the voltage output terminal, and the charge pump stage is also connected to the amplified output terminal through the buffer stage for adjusting the voltage conversion amplitude according to the voltage signal output by the error amplifier stage. Through the above technical solution, the output signal of the charge pump circuit can be fed back to the input end in real time, so that in the closed-loop negative pressure charge pump circuit, the voltage and current in the circuit can be adjusted in real time according to the feedback result through circuit design, thereby achieving the advantages of improving the performance and stability of the circuit. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The above and other purposes, features and advantages of the embodiments of the present disclosure will become readily understood by reading the detailed description below with reference to the accompanying drawings. In the accompanying drawings, several embodiments of the present disclosure are shown by way of example and not limitation, in which:

[0021] Figure 1 A charge pump circuit according to a preferred embodiment of the present disclosure is shown;

[0022] Figure 2 A charge pump circuit according to a preferred embodiment of the present disclosure is shown;

[0023] Figure 3 A charge pump circuit according to a preferred embodiment of the present disclosure is shown;

[0024] Figure 4 A charge pump circuit according to a preferred embodiment of the present disclosure is shown;

[0025] Figure 5 A charge pump circuit according to a preferred embodiment of the present disclosure is shown;

[0026] Figure 6 A charge pump circuit according to a preferred embodiment of the present disclosure is shown;

[0027] Figure 7A charge pump circuit according to a preferred embodiment of the present disclosure is shown;

[0028] Figure 8 A negative voltage charge pump circuit according to a preferred embodiment of the present disclosure is shown; and

[0029] Fig. 9 A negative voltage charge pump circuit according to a preferred embodiment of the present disclosure is shown. DETAILED DESCRIPTION

[0030] The preferred embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although the preferred embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided to make the present disclosure more thorough and complete, and to fully convey the scope of the present disclosure to those skilled in the art.

[0031] The term "including" and its variations used in this article represent open inclusion, that is, "including but not limited to". Unless otherwise stated, the term "or" means "and / or". The term "based on" means "based at least in part on". The terms "an example embodiment" and "an embodiment" mean "at least one example embodiment". The term "another embodiment" means "at least one other embodiment". The terms "first", "second", etc. may refer to different or the same objects. In the description of this article, unless otherwise specified and limited, the terms "connected" and "connected" should be understood in a broad sense. For example, it can be a direct connection or an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to specific circumstances.

[0032] The charge pump circuit in the prior art is an open loop, which has two input voltages. During operation, by opening and closing a plurality of switches, the charge pump can theoretically convert the output voltage to the voltage of the sum of the two input voltages. However, in actual operation, the range of the input voltage is very large. In this case, the higher the input voltage, the greater the parasitic capacitance generated in the nodes of the charge pump, which results in a greater efficiency loss. Therefore, the output voltage of the open-loop charge pump circuit of the prior art is significantly different from the theoretical value, and the power consumption of each node in the circuit is very large. Moreover, the open-loop charge pump circuit of the prior art is not suitable for cascading, because a large parasitic capacitance will be generated on the relevant nodes of the second stage, which will greatly deteriorate the efficiency of the charge pump. Moreover, when the charge pump circuit of the prior art requires a higher voltage boost, it is necessary to use switches and capacitors that withstand high voltages, which greatly increases the area overhead.

[0033] In order to solve the problems in the prior art, an embodiment of the present disclosure provides an improved charge pump circuit.

[0034] Figure 1 A charge pump circuit according to a preferred embodiment of the present disclosure is shown. The charge pump circuit includes a detection feedback stage, an error amplifier stage, and a charge pump stage. The detection feedback stage includes a voltage difference detection unit and a feedback network, and an input voltage VIN and an output voltage VCP are connected to two input terminals of the voltage difference detection unit. The output terminal of the voltage difference detection unit is connected to one end of the feedback network and to the first input terminal of the error amplifier stage. Figure 1 The first input terminal of the error amplifier stage is shown as a negative electrode, but this is only exemplary and the present invention is not limited thereto. The other end of the feedback network is connected to a reference potential. Figure 1 The reference potential is shown to be grounded, but this is only exemplary and the present invention is not limited to this. The detection feedback stage detects the voltage difference between the output voltage VCP of the charge pump and the input voltage VIN to generate a feedback voltage VFB. The feedback voltage VFB is input to the first input terminal of the error amplifier stage. In an exemplary embodiment, the first input terminal of the error amplifier stage is an inverting input terminal or a non-inverting input terminal, and the second input terminal of the error amplifier stage is a non-inverting input terminal or an inverting input terminal. Alternatively, the first input terminal of the error amplifier stage is a non-inverting input terminal or an inverting input terminal, and the second input terminal of the error amplifier stage is an inverting input terminal or a non-inverting input terminal.

[0035] Reference Figure 1 The charge pump circuit of the preferred embodiment of the present disclosure is a closed-loop circuit. The output voltage VCP is connected to the detection feedback stage, and is compared with the input voltage VIN to generate a voltage difference, which is input to the error amplifier stage as the feedback voltage VFB. The detection feedback stage of the charge pump circuit is used to generate a feedback voltage based on the input voltage and the output voltage. Such a design can make the output signal of the charge pump circuit be fed back to the input end in real time, so that in the closed-loop charge pump circuit, the voltage and current in the circuit can be adjusted in real time according to the feedback result through the design of the circuit, thereby achieving the advantages of improving the performance and stability of the circuit.

[0036] Continue to refer to Figure 1 , the output signal of the detection feedback stage is transmitted to the error amplifier stage. The error amplifier stage of the charge pump circuit includes a first input terminal (e.g., a negative electrode), a second input terminal (e.g., a positive electrode) and an amplifier output terminal. The first input terminal (e.g., a negative electrode) of the error amplifier stage receives the feedback voltage VFB, and the second input terminal (e.g., a positive electrode) of the error amplifier stage receives the reference voltage Vref. The reference voltage Vref is preset. The amplifier output terminal of the error amplifier stage can be connected to the control terminal (gate) of the first power tube M1 of the charge pump stage. The error amplifier stage amplifies the voltage difference between VFB and Vref, and the amplifier output terminal of the error amplifier stage outputs the amplified first voltage VG1 to the control terminal of the first power tube M1 of the charge pump stage. Figure 1In the embodiment of the present invention, the first input terminal of the error amplifier stage may be a negative electrode, and the second input terminal may be a positive electrode, but the present invention is not limited thereto.

[0037] The error amplifier stage can be used to amplify the small difference of the input signal to a measurable range, so that it can be detected and measured. The error amplifier stage can accurately detect the change of voltage. Figure 1 As shown, the error amplifier stage is used to amplify the voltage difference between the feedback voltage and the reference voltage. In other words, the error amplifier stage is used to output a first voltage based on the feedback voltage and the reference voltage. The feedback voltage and the reference voltage are compared and amplified by the error amplifier stage, so that the first voltage output by the error amplifier stage can change with the change of the feedback voltage, thereby causing the output voltage of the charge pump stage to change, thereby achieving the purpose of automatically adjusting the voltage in the closed-loop circuit. At the same time, the error amplifier stage can also enhance stability by adding a compensation capacitor on the feedback path to prevent oscillation and shock. In an exemplary embodiment, the error amplifier stage is preferably an error amplifier.

[0038] Continue to refer to Figure 1 , the output signal of the error amplifier stage is transmitted to the charge pump stage. The charge pump stage includes a first power tube M1, a first capacitor C1, a first switch S1, a second switch S2, a third switch S3, and a fourth switch S4. The charge pump stage has an input voltage VIN and an output voltage VCP. The nodes at one end of the first capacitor C1 are respectively connected to the input voltage VIN through the first switch S1 and to the output voltage VCP through the fourth switch S4. The nodes at the other end of the first capacitor C1 are respectively connected to the input voltage VIN through the third switch S3 and to the first electrode (e.g., drain) of the first power tube M1 through the second switch S2. The second electrode (e.g., source) of the first power tube M1 is connected to a reference potential. As described above, the input voltage VIN and the output voltage VCP are also connected to the voltage difference detection unit of the detection feedback stage. In Figure 1 In the embodiment of the present invention, the first electrode of the first power tube M1 may be a drain, the second electrode may be a source, and the reference potential is grounded, but the present invention is not limited thereto.

[0039] Figure 1The working process of the charge pump stage shown includes two stages: in the first stage, the first switch S1 and the second switch S2 are closed, the third switch S3 and the fourth switch S4 are disconnected, and the input voltage VIN is connected to the first pole (e.g., drain) of the first power tube M1 through the closed first switch S1, the first capacitor C1, and the closed second switch S2. In the first stage, the charge pump stage charges the first capacitor C1 through the first power tube M1, and the size of the charging current is adjusted by the loop according to the size of the load. In the second stage, the first switch S1 and the second switch S2 are disconnected, the third switch S3 and the fourth switch S4 are closed, and the input voltage VIN is connected to the output voltage VCP through the closed third switch S3, the first capacitor C1, and the closed fourth switch S4. In the second stage, the charge pump stage supplies power to the load under the output voltage VCP through the first capacitor C1. Thus, the preferred embodiment of the present disclosure realizes the conversion of input voltage to output voltage.

[0040] The charge pump stage is used to convert the input voltage into an output voltage. The first power tube M1 in the charge pump stage is used to form a current flowing therethrough, and the current in the first power tube M1 can change according to the change of the control terminal voltage, thereby changing the current in response to the change of the control terminal voltage and thus changing the output voltage, thereby realizing the function of automatically adjusting the voltage. In an exemplary embodiment, the control terminal voltage can be a voltage signal output from the amplified output terminal of the error amplifier stage. Specifically, the function of adjusting the voltage of the embodiment of the present disclosure is realized in the following manner: (1) If the feedback voltage VFB increases, the reference voltage Vref is unchanged, and the feedback voltage is connected to the first input terminal (e.g., the negative electrode) of the error amplifier stage, so the first voltage VG1 output from the error amplifier stage decreases as the feedback voltage increases. Since the voltage (first voltage VG1) on the control terminal of the first power tube decreases, the current flowing through the first power tube becomes smaller. As the current flowing through the first power tube decreases, the charge charged to the first capacitor C1 decreases, thereby the output voltage VCP decreases. As the output voltage decreases, the feedback voltage output by the voltage difference detection unit decreases. The above cycle achieves the effect of lowering the feedback voltage when the feedback voltage is high. (2) On the contrary, if the feedback voltage VFB decreases, the reference voltage Vref remains unchanged, and the feedback voltage is connected to the first input terminal (e.g., the negative electrode) of the error amplifier stage, so the first voltage VG1 output from the error amplifier stage increases as the feedback voltage decreases. Since the voltage (first voltage VG1) on the control terminal of the first power tube increases, the current flowing through the first power tube becomes larger. As the current flowing through the first power tube increases, the charge charged to the first capacitor C1 increases, thereby increasing the output voltage VCP. As the output voltage increases, the feedback voltage output by the voltage difference detection unit increases. The above cycle achieves the effect of raising the feedback voltage when the feedback voltage is low. Therefore, the embodiment of the present disclosure can adjust the voltage conversion amplitude according to the voltage signal output by the error amplifier stage. It can be seen that through the design of the charge pump circuit and the characteristics of each component, automatic voltage adjustment is achieved.

[0041] Figure 2 A charge pump circuit according to a preferred embodiment of the present disclosure is shown. The charge pump circuit includes a detection feedback stage, an error amplification stage, and a charge pump stage, wherein the charge pump stage includes N charge pump units, and the N charge pump units are connected to form an N-phase charge pump structure, where N is a positive integer. Figure 2 The dual-phase charge pump structure is shown as an example, but the present invention is not limited thereto. The detection feedback stage includes a voltage difference detection unit and a feedback network, the input voltage VIN and the output voltage VCP are connected to two input terminals of the voltage difference detection unit, and the output terminal of the voltage difference detection unit is connected to one terminal of the feedback network and to the first input terminal of the error amplifier stage. Figure 2The first input terminal of the error amplifier stage is shown as a negative electrode, but this is only exemplary and the present invention is not limited thereto. The other end of the feedback network is connected to a reference potential. Figure 2 The reference potential is shown to be grounded, but this is only exemplary and the present invention is not limited to this. The detection feedback stage detects the voltage difference between the output voltage VCP of the charge pump and the input voltage VIN to generate a feedback voltage VFB. The feedback voltage VFB is input to the first input terminal of the error amplifier stage. In an exemplary embodiment, the first input terminal of the error amplifier stage is an inverting input terminal or a non-inverting input terminal, and the second input terminal of the error amplifier stage is a non-inverting input terminal or an inverting input terminal. Alternatively, the first input terminal of the error amplifier stage is a non-inverting input terminal or an inverting input terminal, and the second input terminal of the error amplifier stage is an inverting input terminal or a non-inverting input terminal.

[0042] Figure 2 The charge pump circuit shown is a closed-loop circuit. The output voltage VCP is connected to the detection feedback stage and compared with the input voltage VIN to generate a voltage difference, which is input to the error amplifier stage as the feedback voltage VFB. The detection feedback stage of the charge pump circuit is used to generate a feedback voltage based on the input voltage and the output voltage. Such a design allows the output signal of the charge pump circuit to be fed back to the input terminal in real time, so that in the closed-loop charge pump circuit, the voltage and current in the circuit can be adjusted in real time according to the feedback result through the design of the circuit, thereby achieving the advantages of improving the performance and stability of the circuit.

[0043] Continue to refer to Figure 2 , the output signal of the detection feedback stage is transmitted to the error amplifier stage. The error amplifier stage of the charge pump circuit includes a first input terminal (e.g., a negative electrode), a second input terminal (e.g., a positive electrode) and an amplifier output terminal. The first input terminal (e.g., a negative electrode) of the error amplifier stage receives the feedback voltage VFB, and the second input terminal (e.g., a positive electrode) of the error amplifier stage receives the reference voltage Vref. The reference voltage Vref is preset. The amplifier output terminal of the error amplifier stage is connected to the control terminal (gate) of the first power tube M1 of the charge pump stage. The error amplifier stage amplifies the voltage difference between VFB and Vref, and the amplifier output terminal of the error amplifier stage outputs the amplified first voltage VG1 to the control terminal of the first power tube M1 of the charge pump stage. Figure 2 In the embodiment of the present invention, the first input terminal of the error amplifier stage may be a negative electrode, and the second input terminal may be a positive electrode, but the present invention is not limited thereto.

[0044] like Figure 2As shown, the error amplifier stage is used to amplify the voltage difference between the feedback voltage and the reference voltage. In other words, the error amplifier stage is used to output a first voltage based on the feedback voltage and the reference voltage. By comparing and amplifying the feedback voltage and the reference voltage through the error amplifier stage, the first voltage output by the error amplifier stage can change with the change of the feedback voltage, thereby causing the output voltage of the charge pump stage to change, thereby achieving the purpose of automatically adjusting the voltage in the closed-loop circuit. At the same time, the error amplifier stage can also enhance stability by adding a compensation capacitor on the feedback path to prevent oscillation and shock. In an exemplary embodiment, the error amplifier stage is preferably an error amplifier.

[0045] Continue to refer to Figure 2 , taking the dual-phase charge pump structure as an example, the output signal of the error amplifier stage is transmitted to the charge pump stage. The charge pump stage includes a first power tube M1, a first capacitor C1, a second capacitor C2, a first switch S1, a second switch S2, a third switch S3, a fourth switch S4, a fifth switch S5, a sixth switch S6, a seventh switch S7, and an eighth switch S8. The charge pump stage has an input voltage VIN and an output voltage VCP. The nodes at one end of the first capacitor C1 are respectively connected to the input voltage VIN through the first switch S1 and connected to the output voltage VCP through the fourth switch S4. The nodes at the other end of the first capacitor C1 are respectively connected to the input voltage VIN through the third switch S3 and connected to the first pole (e.g., drain) of the first power tube M1 through the second switch S2. The nodes at one end of the second capacitor C2 are respectively connected to the input voltage VIN through the fifth switch S5 and connected to the output voltage VCP through the eighth switch S8. The nodes at the other end of the second capacitor C2 are respectively connected to the input voltage VIN through the seventh switch S7 and connected to the first pole (e.g., drain) of the first power tube M1 through the sixth switch S6. The second electrode (eg, source electrode) of the first power tube M1 is connected to the reference potential. As mentioned above, the input voltage VIN and the output voltage VCP are also connected to the voltage difference detection unit of the detection feedback stage. Figure 2 In the embodiment of the present invention, the first electrode of the first power tube M1 may be a drain, the second electrode may be a source, and the reference potential is grounded, but the present invention is not limited thereto.

[0046] Figure 2The working process of the charge pump stage circuit shown includes two stages: in the first stage, the first switch S1 and the second switch S2 are closed, the third switch S3 and the fourth switch S4 are disconnected, and the input voltage VIN is connected to the first pole (e.g., drain) of the first power tube M1 through the closed first switch S1, the first capacitor C1, and the closed second switch S2. In the first stage, the charge pump stage charges the first capacitor C1 through the first power tube M1, and the size of the charging current is adjusted by the loop according to the size of the load. At the same time, the fifth switch S5 and the sixth switch S6 are disconnected, the seventh switch S7 and the eighth switch S8 are closed, and the input voltage VIN is connected to the output voltage VCP through the closed seventh switch S7, the second capacitor C2, and the closed eighth switch S8. In the first stage, the charge pump stage supplies power to the load under the output voltage VCP through the second capacitor C2.

[0047] In the second stage, the first switch S1 and the second switch S2 are disconnected, the third switch S3 and the fourth switch S4 are closed, and the input voltage VIN is connected to the output voltage VCP through the closed third switch S3, the first capacitor C1, and the closed fourth switch S4. In the second stage, the charge pump stage supplies power to the load under the output voltage VCP through the first capacitor C1. At the same time, the fifth switch S5 and the sixth switch S6 are closed, the seventh switch S7 and the eighth switch S8 are disconnected, and the input voltage VIN is connected to the first pole (e.g., drain) of the first power tube M1 through the closed fifth switch S5, the second capacitor C2, and the closed sixth switch S6. In the second stage, the charge pump stage charges the second capacitor C2 through the first power tube M1, and the size of the charging current is adjusted by the loop according to the size of the load. Thus, the preferred embodiment of the present disclosure realizes the conversion of input voltage to output voltage.

[0048] By using a dual-phase charge pump stage, two capacitors can be charged and discharged alternately, thereby improving the working efficiency of the charge pump. Similarly, in the case of a multi-phase charge pump stage, multiple capacitors can be charged and discharged alternately, thereby improving the working efficiency of the charge pump.

[0049] Figure 3 A charge pump circuit according to a preferred embodiment of the present disclosure is shown. The charge pump circuit comprises a detection feedback stage, an error amplification stage, and a charge pump stage, wherein the charge pump stage comprises N charge pump units, and the N charge pump units are cascaded (connected in series), where N is a positive integer. Figure 3 The two-stage charge pump structure is shown as an example, but the present invention is not limited thereto. The detection feedback stage includes a voltage difference detection unit and a feedback network, the input voltage VIN and the output voltage VCP are connected to two input terminals of the voltage difference detection unit, and the output terminal of the voltage difference detection unit is connected to one terminal of the feedback network and to the first input terminal of the error amplifier stage. Figure 3The first input terminal of the error amplifier stage is shown as a negative electrode, but this is only exemplary and the present invention is not limited thereto. The other end of the feedback network is connected to a reference potential. Figure 3 The reference potential is shown to be grounded, but this is only exemplary and the present invention is not limited to this. The detection feedback stage detects the voltage difference between the output voltage VCP of the charge pump and the input voltage VIN to generate a feedback voltage VFB. The feedback voltage VFB is input to the first input terminal of the error amplifier stage. In an exemplary embodiment, the first input terminal of the error amplifier stage is an inverting input terminal or a non-inverting input terminal, and the second input terminal of the error amplifier stage is a non-inverting input terminal or an inverting input terminal. Alternatively, the first input terminal of the error amplifier stage is a non-inverting input terminal or an inverting input terminal, and the second input terminal of the error amplifier stage is an inverting input terminal or a non-inverting input terminal.

[0050] Figure 3 The charge pump circuit shown is a closed-loop circuit. The output voltage VCP is connected to the detection feedback stage and compared with the input voltage VIN to generate a voltage difference, which is input to the error amplifier stage as the feedback voltage VFB. The detection feedback stage of the charge pump circuit is used to generate a feedback voltage based on the input voltage and the output voltage. Such a design allows the output signal of the charge pump circuit to be fed back to the input terminal in real time, so that in the closed-loop charge pump circuit, the voltage and current in the circuit can be adjusted in real time according to the feedback result through the design of the circuit, thereby achieving the advantages of improving the performance and stability of the circuit.

[0051] Continue to refer to Figure 3 , the output signal of the detection feedback stage is transmitted to the error amplifier stage. The error amplifier stage includes a first input terminal (e.g., a negative electrode), a second input terminal (e.g., a positive electrode) and an amplifier output terminal. The first input terminal (e.g., a negative electrode) of the error amplifier stage receives the feedback voltage VFB, and the second input terminal (e.g., a positive electrode) of the error amplifier stage receives the reference voltage Vref. The reference voltage Vref is preset. The amplifier output terminal of the error amplifier stage is connected to the control terminal (gate) of the first power tube M1 of the charge pump stage. The error amplifier stage amplifies the voltage difference between VFB and Vref, and the amplifier output terminal of the error amplifier stage outputs the amplified first voltage VG1 to the control terminal of the first power tube M1 of the charge pump stage. Figure 3 In the embodiment of the present invention, the first input terminal of the error amplifier stage may be a negative electrode, and the second input terminal may be a positive electrode, but the present invention is not limited thereto.

[0052] like Figure 3As shown, the error amplifier stage is used to amplify the voltage difference between the feedback voltage and the reference voltage. In other words, the error amplifier stage is used to output a first voltage based on the feedback voltage and the reference voltage. By comparing and amplifying the feedback voltage and the reference voltage through the error amplifier stage, the first voltage output by the error amplifier stage can change with the change of the feedback voltage, thereby causing the output voltage of the charge pump stage to change, thereby achieving the purpose of automatically adjusting the voltage in the closed-loop circuit. At the same time, the error amplifier stage can also enhance stability by adding a compensation capacitor on the feedback path to prevent oscillation and shock. In an exemplary embodiment, the error amplifier stage is preferably an error amplifier.

[0053] Continue to refer to Figure 3 , taking the two-stage cascade charge pump structure as an example, the output signal of the error amplifier stage is transmitted to the charge pump stage. The charge pump stage includes a first power tube M1, a first capacitor C1, a second capacitor C2, a first switch S1, a second switch S2, a third switch S3, a fourth switch S4, a fifth switch S5, a sixth switch S6, a seventh switch S7, and an eighth switch S8. The charge pump stage has an input voltage VIN and an output voltage VCP. The nodes at one end of the first capacitor C1 are respectively connected to the input voltage VIN through the first switch S1 and connected to the next level (second level) charge pump unit through the fourth switch S4. The nodes at the other end of the first capacitor C1 are respectively connected to the input voltage VIN through the third switch S3 and connected to the first pole (e.g., drain) of the first power tube M1 through the second switch S2. The nodes at one end of the second capacitor C2 are respectively connected to the previous level (first level) charge pump unit through the fifth switch S5 and connected to the output voltage VCP through the eighth switch S8. The node at the other end of the second capacitor C2 is connected to the charge pump unit of the previous stage (first stage) through the seventh switch S7 and connected to the first electrode (e.g., drain) of the first power tube M1 through the sixth switch S6. The second electrode (e.g., source) of the first power tube M1 is connected to the reference potential. As mentioned above, the input voltage VIN and the output voltage VCP are also connected to the voltage difference detection unit of the detection feedback stage. Figure 3 In the embodiment of the present invention, the first electrode of the first power tube M1 may be a drain, the second electrode may be a source, and the reference potential is grounded, but the present invention is not limited thereto.

[0054] Figure 3The working process of the charge pump stage circuit shown includes two stages: in the first stage, the first switch S1 and the second switch S2 are closed, the third switch S3 and the fourth switch S4 are disconnected, and the input voltage VIN is connected to the first pole (e.g., drain) of the first power tube M1 through the closed first switch S1, the first capacitor C1, and the closed second switch S2. In the first stage, the charge pump stage charges the first capacitor C1 through the first power tube M1, and the size of the charging current is adjusted by the loop according to the size of the load. At the same time, the fifth switch S5 and the sixth switch S6 are disconnected, the seventh switch S7 and the eighth switch S8 are closed, and the upper level (first level) charge pump unit is connected to the output voltage VCP through the closed seventh switch S7, the second capacitor C2, and the closed eighth switch S8. In the first stage, the charge pump stage supplies power to the load under the output voltage VCP through the second capacitor C2.

[0055] In the second stage, the first switch S1 and the second switch S2 are disconnected, the third switch S3 and the fourth switch S4 are closed, and the input voltage VIN is connected to the next level (second level) charge pump unit through the closed third switch S3, the first capacitor C1, and the closed fourth switch S4. In the second stage, the charge pump stage converts the voltage to the upper level (first level) output voltage higher than the input voltage through the first capacitor C1. At the same time, the fifth switch S5 and the sixth switch S6 are closed, the seventh switch S7 and the eighth switch S8 are disconnected, and the upper level (first level) output voltage is connected to the first pole (e.g., drain) of the first power tube M1 through the closed fifth switch S5, the second capacitor C2, and the closed sixth switch S6. In the second stage, the charge pump stage charges the second capacitor C2 through the first power tube M1, and the size of the charging current is adjusted by the loop according to the size of the load. Thus, the preferred embodiment of the present disclosure realizes the conversion of input voltage to output voltage.

[0056] By using two cascaded charge pump stages, it is equivalent to connecting two capacitors in series, so that the voltage can be converted to a higher level. Similarly, in the case of multi-stage cascaded charge pump stages, it is equivalent to connecting multiple capacitors in series, so that the voltage can be converted to a higher level.

[0057] Figure 4 A charge pump circuit according to a preferred embodiment of the present disclosure is shown. The charge pump circuit includes a detection feedback stage, an error amplifier stage, a buffer stage, and a charge pump stage. The detection feedback stage includes a voltage difference detection unit and a feedback network, an input voltage VIN and an output voltage VCP are connected to two input ends of the voltage difference detection unit, and an output end of the voltage difference detection unit is connected to one end of the feedback network and to a first input end of the error amplifier stage. Figure 4 The first input terminal of the error amplifier stage is shown as a positive electrode, but this is only exemplary and the present invention is not limited thereto. The other end of the feedback network is connected to a reference potential. Figure 4The reference potential is shown as grounded, but this is only exemplary and the present invention is not limited thereto. The other end of the feedback network is connected to the reference potential. Figure 4 The reference potential is shown to be grounded, but this is only exemplary and the present invention is not limited to this. The detection feedback stage detects the voltage difference between the output voltage VCP of the charge pump and the input voltage VIN to generate a feedback voltage VFB. The feedback voltage VFB is input to the first input terminal of the error amplifier stage. In an exemplary embodiment, the first input terminal of the error amplifier stage is an inverting input terminal or a non-inverting input terminal, and the second input terminal of the error amplifier stage is a non-inverting input terminal or an inverting input terminal. Alternatively, the first input terminal of the error amplifier stage is a non-inverting input terminal or an inverting input terminal, and the second input terminal of the error amplifier stage is an inverting input terminal or a non-inverting input terminal.

[0058] Figure 4 The charge pump circuit shown is a closed-loop circuit. The output voltage VCP is connected to the detection feedback stage and compared with the input voltage VIN to generate a voltage difference, which is input to the error amplifier stage as the feedback voltage VFB. The detection feedback stage of the charge pump circuit is used to generate a feedback voltage based on the input voltage and the output voltage. Such a design allows the output signal of the charge pump circuit to be fed back to the input terminal in real time, so that in the closed-loop charge pump circuit, the voltage and current in the circuit can be adjusted in real time according to the feedback result through the design of the circuit, thereby achieving the advantages of improving the performance and stability of the circuit.

[0059] Continue to refer to Figure 4 , the output signal of the detection feedback stage is transmitted to the error amplifier stage. The error amplifier stage includes a first input terminal (e.g., a positive electrode), a second input terminal (e.g., a negative electrode) and an amplifier output terminal. The first input terminal (e.g., a positive electrode) of the error amplifier stage receives the feedback voltage VFB, and the second input terminal (e.g., a negative electrode) of the error amplifier stage receives the reference voltage Vref. The reference voltage Vref is preset. The amplifier output terminal of the error amplifier stage is connected to the control terminal (gate) of the third power tube M3 of the buffer stage. The error amplifier stage amplifies the voltage difference between VFB and Vref, and the amplifier output terminal of the error amplifier stage outputs the amplified second voltage VG2 to the control terminal of the third power tube M3 of the buffer stage. Figure 4 In the embodiment of the present invention, the first input terminal of the error amplifier stage may be a positive electrode, and the second input terminal may be a negative electrode, but the present invention is not limited thereto.

[0060] The buffer stage includes a second power tube M2 and a third power tube M3. The control end (gate) of the second power tube M2 is connected to the control end (gate) of the first power tube M1 of the charge pump stage. The first electrode (e.g., drain) of the second power tube M2 is connected to the first electrode (e.g., drain) of the third power tube M3 and to the control end of the second power tube M2. The second electrode (e.g., source) of the second power tube M2 is connected to a reference potential. The control end of the third power tube M3 is connected to the amplified output end of the error amplifier stage and receives a second voltage VG2 from the error amplifier stage. The first electrode (e.g., drain) of the third power tube M3 is connected to the first electrode (e.g., drain) of the second power tube M2 and to the control end of the second power tube M2. The second electrode (e.g., source) of the third power tube M3 is connected to the operating voltage VDD. The buffer stage is used to adjust the current of the first power tube M1 of the charge pump stage. The buffer stage can provide isolation between circuits to prevent interference from input and other circuits from affecting the output. Moreover, the buffer can also ensure the stability and correctness of signal transmission.

[0061] Continue to refer to Figure 4 , the output signal of the buffer stage is transmitted to the charge pump stage. The charge pump stage includes a first power tube M1, a first capacitor C1, a first switch S1, a second switch S2, a third switch S3, and a fourth switch S4. The charge pump stage circuit has an input voltage VIN and an output voltage VCP. The nodes at one end of the first capacitor C1 are respectively connected to the input voltage VIN through the first switch S1 and to the output voltage VCP through the fourth switch S4. The nodes at the other end of the first capacitor C1 are respectively connected to the input voltage VIN through the third switch S3 and to the first electrode (e.g., drain) of the first power tube M1 through the second switch S2. The second electrode (e.g., source) of the first power tube M1 is connected to a reference potential. As described above, the input voltage VIN and the output voltage VCP are also connected to the voltage difference detection unit of the detection feedback stage. In Figure 4 In the embodiment, the first electrode of the first power tube M1 can be a drain, and the second electrode can be a source; the first electrode of the second power tube M2 can be a drain, and the second electrode can be a source; the first electrode of the third power tube M3 can be a drain, and the second electrode can be a source, and the reference potential is grounded, but the present invention is not limited to this.

[0062] Figure 4 The charge pump stage circuit shown in the figure works in the same way as Figure 1 The working process of the charge pump stage circuit is similar and will not be repeated here.

[0063] The charge pump stage is used to convert the input voltage into the output voltage. Specifically, the voltage adjustment function of the embodiment of the present disclosure is realized in the following manner: (1) If the feedback voltage VFB increases, the reference voltage Vref is unchanged, and the feedback voltage is connected to the first input terminal (e.g., the positive electrode) of the error amplifier stage, so the second voltage VG2 output from the error amplifier stage increases as the feedback voltage increases. Since the voltage (second voltage VG2) on the control terminal of the third power tube M3 increases, the driving voltage Vgs of the third power tube M3 decreases, so the current flowing through the third power tube M3 decreases, and the current flowing through the second power tube M2 also decreases. As the current flowing through the second power tube M2 decreases, the first voltage VG1 at the control terminal of the second power tube M2 decreases, so the current flowing through the first power tube M1 decreases. As the current flowing through the first power tube M1 decreases, the charge charged to the first capacitor C1 decreases, thereby the output voltage VCP decreases. As the output voltage decreases, the feedback voltage output by the voltage difference detection unit decreases. The above cycle achieves the effect of lowering the feedback voltage when the feedback voltage is high. (2) On the contrary, if the feedback voltage VFB decreases, the reference voltage Vref remains unchanged, and the feedback voltage is connected to the first input terminal (e.g., the positive electrode) of the error amplifier stage, so the second voltage VG2 output from the error amplifier stage decreases as the feedback voltage decreases. Since the voltage (second voltage VG2) on the control terminal of the third power tube M3 decreases, the driving voltage Vgs of the third power tube M3 increases, so the current flowing through the third power tube M3 increases, and the current flowing through the second power tube M2 also increases. As the current flowing through the second power tube M2 increases, the first voltage VG1 at the control terminal of the second power tube M2 increases, so the current flowing through the first power tube M1 increases. As the current flowing through the first power tube M1 increases, the charge charged to the first capacitor C1 increases, thereby increasing the output voltage VCP. As the output voltage increases, the feedback voltage output by the voltage difference detection unit increases. The above cycle achieves the effect of raising the feedback voltage when the feedback voltage is low. Therefore, the embodiments of the present disclosure can adjust the voltage conversion amplitude according to the voltage signal output by the error amplifier stage.

[0064] Figure 5 A charge pump circuit according to a preferred embodiment of the present disclosure is shown. The charge pump circuit includes a detection feedback stage, an error amplification stage, a buffer stage, and a charge pump stage, wherein the charge pump stage includes N charge pump units, and the N charge pump units are connected to form an N-phase charge pump structure, where N is a positive integer. Figure 5The dual-phase charge pump structure is shown as an example, but the present invention is not limited thereto. The detection feedback stage includes a voltage difference detection unit and a feedback network, the input voltage VIN and the output voltage VCP are connected to two input terminals of the voltage difference detection unit, and the output terminal of the voltage difference detection unit is connected to one terminal of the feedback network and to the first input terminal of the error amplifier stage. Figure 2 The first input terminal of the error amplifier stage is shown as a positive electrode, but this is only exemplary and the present invention is not limited thereto. The other end of the feedback network is connected to a reference potential. Figure 5 The reference potential is shown to be grounded, but this is only exemplary and the present invention is not limited to this. The detection feedback stage detects the voltage difference between the output voltage VCP of the charge pump and the input voltage VIN to generate a feedback voltage VFB. The feedback voltage VFB is input to the first input terminal of the error amplifier stage. In an exemplary embodiment, the first input terminal of the error amplifier stage is an inverting input terminal or a non-inverting input terminal, and the second input terminal of the error amplifier stage is a non-inverting input terminal or an inverting input terminal. Alternatively, the first input terminal of the error amplifier stage is a non-inverting input terminal or an inverting input terminal, and the second input terminal of the error amplifier stage is an inverting input terminal or a non-inverting input terminal.

[0065] Continue to refer to Figure 5 , the output signal of the detection feedback stage is transmitted to the error amplifier stage. The error amplifier stage includes a first input terminal (e.g., a positive electrode), a second input terminal (e.g., a negative electrode) and an amplifier output terminal. The first input terminal (e.g., a positive electrode) of the error amplifier stage receives the feedback voltage VFB, and the second input terminal (e.g., a negative electrode) of the error amplifier stage receives the reference voltage Vref. The reference voltage Vref is preset. The amplifier output terminal of the error amplifier stage is connected to the control terminal (gate) of the first power tube M1 of the charge pump stage. The error amplifier stage amplifies the voltage difference between VFB and Vref, and the amplifier output terminal of the error amplifier stage outputs the amplified second voltage VG2 to the control terminal of the third power tube M3 of the buffer stage. Figure 5 In the embodiment of the present invention, the first input terminal of the error amplifier stage may be a positive electrode, and the second input terminal may be a negative electrode, but the present invention is not limited thereto.

[0066] The buffer stage includes a second power tube M2 and a third power tube M3. The control end (gate) of the second power tube M2 is connected to the control end (gate) of the first power tube M1 of the charge pump stage. The first electrode (e.g., drain) of the second power tube M2 is connected to the first electrode (e.g., drain) of the third power tube M3 and to the control end of the second power tube M2. The second electrode (e.g., source) of the second power tube M2 is connected to a reference potential. The control end of the third power tube M3 is connected to the amplified output end of the error amplifier stage and receives a second voltage VG2 from the error amplifier stage. The first electrode (e.g., drain) of the third power tube M3 is connected to the first electrode (e.g., drain) of the second power tube M2 and to the control end of the second power tube M2. The second electrode (e.g., source) of the third power tube M3 is connected to the operating voltage VDD. The buffer stage is used to adjust the current of the first power tube M1 of the charge pump stage. The buffer stage can provide isolation between circuits to prevent interference from input and other circuits from affecting the output. Moreover, the buffer can also ensure the stability and correctness of signal transmission.

[0067] Continue to refer to Figure 5 , the output signal of the buffer stage is transmitted to the charge pump stage. The charge pump stage includes a first power tube M1, a first capacitor C1, a second capacitor C2, a first switch S1, a second switch S2, a third switch S3, a fourth switch S4, a fifth switch S5, a sixth switch S6, a seventh switch S7, and an eighth switch S8. The charge pump stage circuit has an input voltage VIN and an output voltage VCP. The nodes at one end of the first capacitor C1 are respectively connected to the input voltage VIN through the first switch S1 and connected to the output voltage VCP through the fourth switch S4. The nodes at the other end of the first capacitor C1 are respectively connected to the input voltage VIN through the third switch S3 and connected to the first pole (e.g., drain) of the first power tube M1 through the second switch S2. The nodes at one end of the second capacitor C2 are respectively connected to the input voltage VIN through the fifth switch S5 and connected to the output voltage VCP through the eighth switch S8. The nodes at the other end of the second capacitor C2 are respectively connected to the input voltage VIN through the seventh switch S7 and connected to the first pole (e.g., drain) of the first power tube M1 through the sixth switch S6. The second pole (e.g., source) of the first power tube M1 is connected to the reference potential. As mentioned above, the input voltage VIN and the output voltage VCP are also connected to the voltage difference detection unit of the detection feedback stage. Figure 5 In the embodiment, the first electrode of the first power tube M1 can be a drain, and the second electrode can be a source; the first electrode of the second power tube M2 can be a drain, and the second electrode can be a source; the first electrode of the third power tube M3 can be a drain, and the second electrode can be a source, and the reference potential is grounded, but the present invention is not limited to this.

[0068] Figure 5 The charge pump stage circuit shown in the figure works in the same way as Figure 2The working process of the charge pump stage circuit is similar and will not be repeated here.

[0069] Figure 5 The charge pump stage circuit shown in the figure has the same working principle as the voltage regulator. Figure 4 The working principle of the voltage adjustment of the charge pump stage circuit is similar and will not be repeated here.

[0070] Figure 6 A charge pump circuit according to a preferred embodiment of the present disclosure is shown. The charge pump circuit comprises a detection feedback stage, an error amplification stage, and a charge pump stage, wherein the charge pump stage comprises N charge pump units, and the N charge pump units are cascaded (connected in series), where N is a positive integer. Figure 6 The two-stage charge pump structure is shown as an example, but the present invention is not limited thereto. The detection feedback stage includes a voltage difference detection unit and a feedback network, the input voltage VIN and the output voltage VCP are connected to two input terminals of the voltage difference detection unit, and the output terminal of the voltage difference detection unit is connected to one terminal of the feedback network and to the first input terminal of the error amplifier stage. Figure 6 It is shown that the first input terminal of the error amplifier stage is a positive electrode, but this is only exemplary and the present invention is not limited to this. The other end of the feedback network is connected to the ground. The detection feedback stage detects the voltage difference between the output voltage VCP of the charge pump and the input voltage VIN to generate a feedback voltage VFB. The feedback voltage VFB is input to the first input terminal of the error amplifier stage. In an exemplary embodiment, the first input terminal of the error amplifier stage is an inverting input terminal or a non-inverting input terminal, and the second input terminal of the error amplifier stage is a non-inverting input terminal or an inverting input terminal. Alternatively, the first input terminal of the error amplifier stage is a non-inverting input terminal or an inverting input terminal, and the second input terminal of the error amplifier stage is an inverting input terminal or a non-inverting input terminal.

[0071] Continue to refer to Figure 6 , the output signal of the detection feedback stage is transmitted to the error amplifier stage. The error amplifier stage includes a first input terminal (e.g., a positive electrode), a second input terminal (e.g., a negative electrode) and an amplifier output terminal. The first input terminal (e.g., a positive electrode) of the error amplifier stage receives the feedback voltage VFB, and the second input terminal (e.g., a negative electrode) of the error amplifier stage receives the reference voltage Vref. The reference voltage Vref is preset. The amplifier output terminal of the error amplifier stage is connected to the control terminal (gate) of the first power tube M1 of the charge pump stage. The error amplifier stage amplifies the voltage difference between VFB and Vref, and the amplifier output terminal of the error amplifier stage outputs the amplified second voltage VG2 to the control terminal of the third power tube M3 of the buffer stage. Figure 6 In the embodiment of the present invention, the first input terminal of the error amplifier stage may be a positive electrode, and the second input terminal may be a negative electrode, but the present invention is not limited thereto.

[0072] The buffer stage includes a second power tube M2 and a third power tube M3. The control end (gate) of the second power tube M2 is connected to the control end (gate) of the first power tube M1 of the charge pump stage. The first electrode (e.g., drain) of the second power tube M2 is connected to the first electrode (e.g., drain) of the third power tube M3 and to the control end of the second power tube M2. The second electrode (e.g., source) of the second power tube M2 is connected to a reference potential. The control end of the third power tube M3 is connected to the amplification output end of the error amplifier stage and receives a second voltage VG2 from the error amplifier stage. The first electrode (e.g., drain) of the third power tube M3 is connected to the first electrode (e.g., drain) of the second power tube M2 and to the control end of the second power tube M2. The second electrode (e.g., source) of the third power tube M3 is connected to the operating voltage VDD. The buffer stage is used to adjust the current of the first power tube M1 of the charge pump stage.

[0073] Continue to refer to Figure 6 , taking the two-stage cascade charge pump structure as an example, the output signal of the buffer stage is transmitted to the charge pump stage. The charge pump stage includes a first power tube M1, a first capacitor C1, a second capacitor C2, a first switch S1, a second switch S2, a third switch S3, a fourth switch S4, a fifth switch S5, a sixth switch S6, a seventh switch S7, and an eighth switch S8. The charge pump stage has an input voltage VIN and an output voltage VCP. The nodes at one end of the first capacitor C1 are respectively connected to the input voltage VIN through the first switch S1 and connected to the next level (second level) charge pump unit through the fourth switch S4. The nodes at the other end of the first capacitor C1 are respectively connected to the input voltage VIN through the third switch S3 and connected to the first pole (e.g., drain) of the first power tube M1 through the second switch S2. The nodes at one end of the second capacitor C2 are respectively connected to the previous level (first level) charge pump unit through the fifth switch S5 and connected to the output voltage VCP through the eighth switch S8. The node at the other end of the second capacitor C2 is connected to the charge pump unit of the previous stage (first stage) through the seventh switch S7 and connected to the first electrode (e.g., drain) of the first power tube M1 through the sixth switch S6. The second electrode (e.g., source) of the first power tube M1 is connected to the reference potential. As mentioned above, the input voltage VIN and the output voltage VCP are also connected to the voltage difference detection unit of the detection feedback stage. Figure 6 In the embodiment, the first electrode of the first power tube M1 can be a drain, and the second electrode can be a source; the first electrode of the second power tube M2 can be a drain, and the second electrode can be a source; the first electrode of the third power tube M3 can be a drain, and the second electrode can be a source, and the reference potential is grounded, but the present invention is not limited to this.

[0074] Figure 6 The charge pump stage circuit shown in the figure works in the same way as Figure 3 The working process of the charge pump stage circuit is similar and will not be repeated here.

[0075] Figure 6 The charge pump stage circuit shown in the figure has the same working principle as the voltage regulator. Figure 4 The working principle of the voltage adjustment of the charge pump stage circuit is similar and will not be repeated here.

[0076] Figure 7 A charge pump circuit according to a preferred embodiment of the present disclosure is shown, which shows a preferred embodiment of the detection feedback stage. The detection feedback stage includes a fourth power tube M4, a fifth power tube M5, a first resistor R1, and a second resistor R2. The input voltage VIN is connected to the second pole (e.g., source) of the fourth power tube M4. The control end of the fourth power tube M4 is connected to the control end of the fifth power tube M5 and to the first pole (e.g., drain) of the fourth power tube M4. The first pole (e.g., drain) of the fourth power tube M4 is connected to one end of the first resistor R1 and to a reference potential. The output voltage VCP is connected to one end of the second resistor R2, and the other end of the second resistor R2 is connected to the second pole (e.g., source) of the fifth power tube M5. The control end of the fifth power tube M5 is connected to the control end of the fourth power tube M4. The first pole (e.g., drain) of the fifth power tube M5 is connected to the other end of the first resistor R1 and to the first input end (e.g., positive pole) of the error amplifier stage. Figure 7 In the embodiment of the present invention, the first electrode of the fourth power tube M4 may be a drain electrode, and the second electrode may be a source electrode; the first electrode of the fifth power tube M5 may be a drain electrode, and the second electrode may be a source electrode, and the reference potential is grounded, but the present invention is not limited thereto.

[0077] Preferably, the operating parameters of the fourth power tube M4 and the fifth power tube M5 are the same, thereby forming a similar current mirror circuit. Since the operating parameters of the fourth power tube M4 and the fifth power tube M5 are the same, the voltages thereon are equal, from which the voltage division on the second resistor R2 and the current passing therethrough can be obtained. Therefore, by detecting the voltage difference between the output voltage VCP and the input voltage VIN through the bias circuit Ib, M4, M5, and the second resistor R2, the current (VCP-VIN) / R2 can be obtained. Using the current (VCP-VIN) / R2 flowing through R1, the feedback voltage VFB=(VCP-VIN)*R1 / R2 can be obtained.

[0078] From the above formula, it can be obtained that VCP - VIN = VFB * R2 / R1. When the loop is working normally, the feedback voltage is equal to the reference voltage, that is, VFB = Vref. Therefore, the boost voltage of the charge pump can be expressed as VCP - VIN = Vref * R2 / R1. It can be seen that the boost voltage of the charge pump can be precisely controlled by controlling the ratio of the second resistor R2 to the first resistor R1. In addition, when the input VIN voltage is low (VIN < Vref * R2 / R1), the first capacitor C1 can be charged to the voltage of VIN at most, and the output voltage VCP can be boosted to 2VIN at most, thus greatly improving the boost ability when the input VIN is low. When the input VIN voltage is high, the first capacitor C1 is charged to the voltage of Vref * R2 / R1 at most. Since Vref * R2 / R1 is much smaller than VIN, the AC loss during the operation of the charge pump is greatly reduced. In addition, in Figure 7 In the charge pump circuit shown, by reasonably designing the magnitude of Vref * R2 / R1, when the charge pumps are connected in multiple stages in series, the first capacitor C1, the first switch S1, the third switch S3, and the fourth switch S4 in each stage can all be implemented using low-voltage MOS transistors. In the prior art, since the boost of the charge pump is not controlled by designing Vref * R2 / R1, high-voltage MOS is required as a switch in use, and MIM or MOS is used as the FLY capacitor. Compared with the existing circuit, the embodiment of the present disclosure has a great area advantage.

[0079] Figure 7 The preferred embodiment of the detection feedback stage is shown. The detection feedback stage according to the preferred embodiment of the present disclosure is not limited thereto. Additionally, Figure 7 The detection feedback stage shown can be used in combination with various charge pump stages, including but not limited to, single-stage charge pump stages, cascaded charge pump stages, and multiphase charge pump stages. Additionally, Figure 7 The detection feedback stage shown can be used in combination with a buffer stage or can be used without a buffer stage.

[0080] Figure 8A negative voltage charge pump circuit according to a preferred embodiment of the present disclosure is shown. The charge pump circuit includes a detection feedback stage, an error amplifier stage, a buffer stage, and a charge pump stage. The detection feedback stage includes a voltage difference detection unit and a feedback network, the output voltage VCP is connected to one input end of the voltage difference detection unit, the other input end of the voltage difference detection unit is connected to a reference potential (e.g., ground), the output end of the voltage difference detection unit is connected to one end of the feedback network and to the first input end (e.g., positive electrode) of the error amplifier stage, the other end of the feedback network is connected to the second pole (e.g., source electrode) of the second power tube M2 of the buffer stage and to the second pole (e.g., source electrode) of the first power tube M1 of the charge pump stage, the voltage at this end is the working voltage VDD, and the working voltage VDD can be used as a reference potential connected to the feedback network. The detection feedback stage detects the voltage difference between the output voltage VCP of the charge pump and the reference potential, and generates a feedback voltage VFB. The feedback voltage VFB is input to the first input end (e.g., positive electrode) of the error amplifier stage.

[0081] The error amplifier stage includes a first input terminal (e.g., a positive terminal), a second input terminal (e.g., a negative terminal), and an amplifier output terminal. The first input terminal (e.g., a positive terminal) of the error amplifier stage receives the feedback voltage VFB, and the second input terminal (e.g., a negative terminal) of the error amplifier stage receives the reference voltage Vref. The reference voltage Vref is preset. The error amplifier stage amplifies the voltage difference between VFB and Vref, and the amplifier output terminal of the error amplifier stage outputs the amplified second voltage VG2 to the control terminal of the third power tube M3 of the buffer stage.

[0082] The buffer stage includes a second power tube M2 and a third power tube M3. The control end of the second power tube M2 is connected to the control end of the first power tube M1 of the charge pump stage. The first electrode (e.g., drain) of the second power tube M2 is connected to the first electrode (e.g., drain) of the third power tube M3 and to the control end of the second power tube M2. The second electrode (e.g., source) of the second power tube M2 is connected to the working voltage. The control end of the third power tube M3 is connected to the amplification output end of the error amplifier stage and receives the second voltage VG2 from the error amplifier stage. The first electrode (e.g., drain) of the third power tube M3 is connected to the first electrode (e.g., drain) of the second power tube M2 and to the control end of the second power tube M2. The second electrode (e.g., source) of the third power tube M3 is connected to a reference potential (e.g., ground). The buffer stage is used to adjust the current of the first power tube M1 of the charge pump stage.

[0083] The charge pump stage includes a first power tube M1, a first capacitor C1, a first switch S1, a second switch S2, a third switch S3, and a fourth switch S4. The charge pump stage circuit has an operating voltage VDD and an output voltage VCP. The nodes at one end of the first capacitor C1 are respectively connected to a reference potential (e.g., ground) through the first switch S1 and connected to the output voltage VCP through the fourth switch S4. The nodes at the other end of the first capacitor C1 are respectively connected to a reference potential (e.g., ground) through the third switch S3 and connected to the first electrode (e.g., drain) of the first power tube M1 through the second switch S2. The second electrode (e.g., source) of the first power tube M1 is connected to the operating voltage VDD.

[0084] Fig. 9 A negative voltage charge pump circuit according to a preferred embodiment of the present disclosure is shown. The charge pump circuit includes a detection feedback stage, an error amplifier stage, a buffer stage, and a charge pump stage. The detection feedback stage includes a voltage difference detection unit and a feedback network, the output voltage VCP is connected to one input end of the voltage difference detection unit, the other input end of the voltage difference detection unit is connected to a reference potential (e.g., ground), the output end of the voltage difference detection unit is connected to one end of the feedback network and to the first input end (e.g., negative pole) of the error amplifier stage, and the other end of the feedback network is connected to the reference potential (e.g., ground). The detection feedback stage detects the voltage difference between the output voltage VCP of the charge pump and the reference potential to generate a feedback voltage VFB. The feedback voltage VFB is input to the first input end (e.g., negative pole) of the error amplifier stage.

[0085] The error amplifier stage includes a first input terminal (e.g., a negative terminal), a second input terminal (e.g., a positive terminal), and an amplifier output terminal. The second input terminal (e.g., a positive terminal) of the error amplifier stage receives the feedback voltage VFB, and the first input terminal (e.g., a negative terminal) of the error amplifier stage receives the reference voltage Vref. The reference voltage Vref is preset. The error amplifier stage amplifies the voltage difference between VFB and Vref, and the amplifier output terminal of the error amplifier stage outputs the amplified second voltage VG2 to the control terminal of the third power tube M3 of the buffer stage.

[0086] The buffer stage includes a second power tube M2 and a third power tube M3. The control end of the second power tube M2 is connected to the control end of the first power tube M1 of the charge pump stage. The first electrode (e.g., drain) of the second power tube M2 is connected to the first electrode (e.g., drain) of the third power tube M3 and to the control end of the second power tube M2. The second electrode (e.g., source) of the second power tube M2 is connected to the operating voltage VDD. The control end of the third power tube M3 is connected to the amplification output end of the error amplifier stage and receives the second voltage VG2 from the error amplifier stage. The first electrode (e.g., drain) of the third power tube M3 is connected to the first electrode (e.g., drain) of the second power tube M2 and to the control end of the second power tube M2. The second electrode (e.g., source) of the third power tube M3 is connected to a reference potential (e.g., ground). The buffer stage is used to adjust the current of the first power tube M1 of the charge pump stage.

[0087] The charge pump stage includes a first power tube M1, a first capacitor C1, a first switch S1, a second switch S2, a third switch S3, and a fourth switch S4. The charge pump stage circuit has an operating voltage VDD and an output voltage VCP. The nodes at one end of the first capacitor C1 are respectively connected to a reference potential (e.g., ground) through the first switch S1 and connected to the output voltage VCP through the fourth switch S4. The nodes at the other end of the first capacitor C1 are respectively connected to a reference potential (e.g., ground) through the third switch S3 and connected to the first electrode (e.g., drain) of the first power tube M1 through the second switch S2. The second electrode (e.g., source) of the first power tube M1 is connected to the operating voltage VDD.

[0088] The technical effects of the embodiments of the present disclosure include: it can be applied to both positive voltage charge pumps and negative voltage charge pumps; the amplitude of boost or buck (conversion amplitude) can be adjusted; the power consumption of the charge pump varies according to the load, and the power consumption is lower under light load; when the input voltage is low, it still has a high boost capability; in the case of multi-stage boost, MOS capacitors can be used for the FLY capacitors of each stage, and most switches can use low-voltage MOS, which has a good area advantage.

[0089] The embodiments of the present disclosure have been described above, and the above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and changes will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments. The selection of terms used herein is intended to best explain the principles of the embodiments, practical applications, or technical improvements in the market, or to enable other persons of ordinary skill in the art to understand the embodiments disclosed herein.

Claims

1. A charge pump circuit, comprising: a detection feedback stage to which a voltage input terminal and a voltage output terminal are connected, and a feedback output terminal of the detection feedback stage generates a feedback voltage based on an output voltage from the voltage output terminal and an input voltage from the voltage input terminal; an error amplifier stage, wherein the feedback output terminal is connected to a first input terminal of the error amplifier stage so that the feedback voltage is input to the error amplifier stage, a second input terminal of the error amplifier stage receives a reference voltage signal, and the error amplifier stage further comprises an amplification output terminal for outputting a voltage signal; as well as A charge pump stage, the charge pump stage comprising a charge pump unit, the charge pump unit being connected to the voltage input terminal, converting the input voltage of the voltage input terminal and outputting it from the voltage output terminal, the charge pump stage being also connected to the amplifier output terminal, and being used to adjust the voltage conversion amplitude according to the voltage signal output by the error amplifier stage, Wherein, the detection feedback stage includes a fourth power tube, a fifth power tube, a first resistor, and a second resistor, the voltage input end is connected to the second pole of the fourth power tube, the control end of the fourth power tube is connected to the control end of the fifth power tube and to the first pole of the fourth power tube, the first pole of the fourth power tube is connected to one end of the first resistor and connected to a reference potential, the voltage output end is connected to one end of the second resistor, the other end of the second resistor is connected to the second pole of the fifth power tube, the control end of the fifth power tube is connected to the control end of the fourth power tube, and the first pole of the fifth power tube is connected to the other end of the first resistor and to the first input end of the error amplifier stage.

2. The charge pump circuit according to claim 1, wherein: The detection feedback stage includes a voltage difference detection unit and a feedback network. The voltage difference detection unit obtains a voltage difference based on the output voltage and the input voltage and generates the feedback voltage through the feedback network.

3. The charge pump circuit according to claim 1, wherein: The charge pump stage includes a first power tube, a first pole or a second pole of the first power tube is connected to the charge pump unit, and a control end of the first power tube receives a voltage signal output by an amplified output end of the error amplifier stage, wherein a current flowing through the first power tube changes with a change in the voltage signal output by the amplified output end.

4. The charge pump circuit according to claim 3, wherein: The charge pump circuit further includes a buffer stage between the error amplifier stage and the charge pump stage, the amplifier output end is connected to the buffer stage, and the buffer output end of the buffer stage is connected to the control end of the first power tube.

5. The charge pump circuit according to claim 4, wherein the buffer stage comprises a second power tube and a third power tube, the control end of the second power tube is connected to the control end of the first power tube of the charge pump stage, the first electrode of the second power tube is connected to the first electrode of the third power tube and to the control end of the second power tube, the second electrode of the second power tube is connected to a reference potential, the control end of the third power tube is connected to the output end of the error amplifier stage and receives a voltage signal from the error amplifier stage, the first electrode of the third power tube is connected to the first electrode of the second power tube and to the control end of the second power tube, and the second electrode of the third power tube is connected to an operating voltage.

6. The charge pump circuit according to claim 1, wherein: The charge pump stage includes a first power tube, a first capacitor, a first switch, a second switch, a third switch, and a fourth switch. The node at one end of the first capacitor is connected to the input voltage through the first switch and to the output voltage through the fourth switch, respectively. The node at the other end of the first capacitor is connected to the input voltage through the third switch and to the first pole of the first power tube through the second switch, and the second pole of the first power tube is connected to the reference potential.

7. The charge pump circuit according to claim 1, wherein: The charge pump stage includes N charge pump units, and the N charge pump units are connected to form an N-phase charge pump structure, wherein N is a positive integer.

8. The charge pump circuit according to claim 1, wherein: The charge pump stage includes a first power tube, a first capacitor, a second capacitor, a first switch, a second switch, a third switch, a fourth switch, a fifth switch, a sixth switch, a seventh switch, and an eighth switch. The node at one end of the first capacitor is connected to the input voltage through the first switch and to the output voltage through the fourth switch, the node at the other end of the first capacitor is connected to the input voltage through the third switch and to the first pole of the first power tube through the second switch, the node at one end of the second capacitor is connected to the input voltage through the fifth switch and to the output voltage through the eighth switch, the node at the other end of the second capacitor is connected to the input voltage through the seventh switch and to the first pole of the first power tube through the sixth switch, the second pole of the first power tube is connected to the reference potential, and the control end of the first power tube is connected to the amplification output end.

9. The charge pump circuit according to claim 1, wherein: The charge pump stage includes a plurality of charge pump units, and the plurality of charge pump units are cascaded.

10. The charge pump circuit according to claim 1, wherein: The charge pump stage includes a first power tube, a first capacitor, a second capacitor, a first switch, a second switch, a third switch, a fourth switch, a fifth switch, a sixth switch, a seventh switch, and an eighth switch. The nodes at one end of the first capacitor are respectively connected to the input voltage through the first switch and to the next-stage charge pump unit through the fourth switch. The nodes at the other end of the first capacitor are respectively connected to the input voltage through the third switch and to the first pole of the first power tube through the second switch. The nodes at one end of the second capacitor are respectively connected to the first stage through the fifth switch and to the output voltage through the eighth switch. The nodes at the other end of the second capacitor are respectively connected to the previous-stage charge pump unit through the seventh switch and to the first pole of the first power tube through the sixth switch. The second pole of the first power tube is connected to the reference potential.

11. A charge pump circuit, comprising: a detection feedback stage, to which a voltage output terminal is connected, and a feedback output terminal of the detection feedback stage generates a feedback voltage based on an output voltage from the voltage output terminal and a reference potential; an error amplifier stage, wherein the feedback output terminal is connected to a first input terminal of the error amplifier stage so that the feedback voltage is input to the error amplifier stage, a second input terminal of the error amplifier stage receives a reference voltage signal, and the error amplifier stage further comprises an amplification output terminal for outputting a voltage signal; a buffer stage, the buffer stage being located between the error amplifier stage and the charge pump stage, the amplifier output end being connected to the buffer stage, and the buffer output end of the buffer stage being connected to the charge pump stage; as well as a charge pump stage, the charge pump stage comprising a charge pump unit, the charge pump unit being connected to the voltage output terminal for changing the voltage and outputting it from the voltage output terminal, the charge pump stage being further connected to the amplifier output terminal through the buffer stage for adjusting the voltage conversion amplitude according to the voltage signal output by the error amplifier stage, Wherein, the detection feedback stage includes a fourth power tube, a fifth power tube, a first resistor, and a second resistor, the voltage input end is connected to the second pole of the fourth power tube, the control end of the fourth power tube is connected to the control end of the fifth power tube and to the first pole of the fourth power tube, the first pole of the fourth power tube is connected to one end of the first resistor and connected to a reference potential, the voltage output end is connected to one end of the second resistor, the other end of the second resistor is connected to the second pole of the fifth power tube, the control end of the fifth power tube is connected to the control end of the fourth power tube, and the first pole of the fifth power tube is connected to the other end of the first resistor and to the first input end of the error amplifier stage.

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