Switched capacitor converter with adjustable output

Abstract

The invention relates to an output-adjustable switched capacitor converter, which belongs to the field of power electronics and integrated circuits, and comprises a plurality of switched capacitor converter modules cascaded in sequence, and a coupling capacitor is connected between any two adjacent switched capacitor converter modules; wherein each switched capacitor converter module is provided with a circuit-changing switch tube, and the circuit-changing switch tube inputs a clock control signal; and each switched capacitor converter module controls the circuit-changing switch tube through the duty ratio of the clock control signal so as to adjust the output transformation ratio. According to the output-adjustable switched capacitor converter, the circuit-changing switch tube is controlled through the clock control signal, the purpose of adjusting the output transformation ratio can be achieved only by adjusting the duty ratio of the clock control signal to control circuit changing of the circuit-changing switch tube, the output-adjustable switched capacitor converter has the advantages of being small in size and light in weight, two different output transformation ratios can be achieved at the same time, and the output-adjustable switched capacitor converter is high in practicability. The control mode is simple, operation is convenient, and expansion cascade connection between the switched capacitor converter modules is also convenient.

Description

Technical Field

[0001] The invention belongs to the field of power electronics and integrated circuits, and in particular relates to a switched capacitor converter with adjustable output. Background Art

[0002] With the rapid development of emerging fields such as wearable devices, vehicle energy and new energy generation, higher requirements are placed on power systems. Features such as miniaturization, lightweight, high efficiency and low electromagnetic interference have become important development directions for power systems. Switching capacitor converters (Switching Capacitor Converters, SCC) are a typical non-magnetic converter whose structure consists only of capacitors and power switches. This structure gives the switched capacitor converter the advantages of small size, light weight, high efficiency, high power density and low electromagnetic interference. Compared with inductors, capacitors are easier to integrate, so switched capacitor converters have significant advantages in miniaturization and integration. Switched capacitor converters have also been widely used in these emerging fields because of their unique advantages. Especially in the field of low-power non-isolated DC-DC applications, switched capacitor converters have developed rapidly and gradually become an important research hotspot.

[0003] Existing switched capacitor converters can usually only obtain voltage changes with fixed ratios. The most direct way to adjust the conversion ratio of the switched capacitor converter is to re-switch the circuit through a large number of switches. The conversion cost of this solution is very high, so another more common method is to cascade the switched capacitor converter with the traditional converter, such as cascading the buck converter with the switched capacitor converter, and adjusting the switched capacitor converter through the control of the traditional converter. Combining the two conversion stages of the buck converter and the switched capacitor converter can also achieve the purpose of adjusting the ratio, but there are still large inductors in the circuit.

[0004] Since most of the existing switched capacitor converters are single working modes with fixed ratios, or require a large number of switches to change the ratio, the use of a large number of switches or large inductors in the circuit violates the original design intention of miniaturization and integration of the switched capacitor converter. Therefore, a switched capacitor converter with adjustable output is needed. Summary of the invention

[0005] In order to solve the above problems existing in the prior art, the present invention provides a switched capacitor converter with adjustable output. The technical problem to be solved by the present invention is achieved through the following technical solutions:

[0006] The present invention provides a switched capacitor converter with adjustable output, comprising: a plurality of switched capacitor converter modules cascaded in sequence, and a coupling capacitor is connected between any two adjacent switched capacitor converter modules; wherein each of the switched capacitor converter modules is provided with a switching switch tube, and the switching switch tube inputs a clock control signal; each of the switched capacitor converter modules controls the switching switch tube through the duty cycle of the clock control signal to adjust the output transformation ratio.

[0007] In one embodiment of the present invention, the switching transistor is an NMOS transistor.

[0008] In one embodiment of the present invention, each of the switch capacitor converter modules includes: an NMOS tube M1, the NMOS tube M1 serving as the switching switch tube and inputting the clock control signal.

[0009] In one embodiment of the present invention, each of the switch capacitor converter modules further includes: NMOS tube MN1, NMOS tube MN2, NMOS tube MN3, diode DN1, diode DN2, diode DN3, capacitor CN1, capacitor CN2, capacitor CN3; wherein the drain end of the NMOS tube MN1 is connected to the positive electrode of the input power supply VCC, the source end of the NMOS tube MN1 is respectively connected to the drain end of the NMOS tube MN3 and the first plate of the capacitor CN1; the drain end of the NMOS tube MN2 is respectively connected to the second plate of the capacitor CN1 and the NMOS tube M1 The source end of the NMOS tube MN2 is connected to the negative electrode of the input power supply VCC; the drain end of the NMOS tube M1 is respectively connected to the source end of the NMOS tube MN3, the cathode of the diode DN1 and the first plate of the capacitor CN3; the anode of the diode DN1 is respectively connected to the first plate of the capacitor CN2 and the cathode of the diode DN2; the anode of the diode DN2 is respectively connected to the second plate of the capacitor CN3 and the cathode of the diode DN3; the source end of the NMOS tube MN2, the second plate of the capacitor CN2 and the anode of the diode DN3 are all grounded.

[0010] In one embodiment of the present invention, the output adjustable switching capacitor converter also includes: a resistor Ro, a capacitor Co and an inductor Lo; the resistor Ro, the capacitor Co and the inductor Lo are respectively connected to the last switching capacitor converter module in a plurality of sequentially cascaded switching capacitor converter modules; wherein the first end of the inductor Lo is connected to the drain end of the NMOS tube M1; the second end of the inductor Lo is respectively connected to the first plate of the capacitor Co and the first end of the resistor Ro; the second plate of the capacitor Co and the second end of the resistor Ro are both grounded.

[0011] In one embodiment of the present invention, the NMOS transistor MN1 inputs a first PWM control signal, and the NMOS transistor MN2 and the NMOS transistor MN3 both input a second PWM control signal; wherein the first PWM control signal and the second PWM control signal have the same frequency and complementary timing.

[0012] In one embodiment of the present invention, the duty cycle of the first PWM control signal and the second PWM control signal are both 50%.

[0013] In one embodiment of the present invention, the output transformation ratio of the switched capacitor converter module is 2:1 or 3:1.

[0014] In one embodiment of the present invention, when the duty cycle of the clock control signal is (0, 0.5], the output transformation ratio of the switch capacitor converter module is 2:1.

[0015] In one embodiment of the present invention, when the duty cycle of the clock control signal is (0.5, 1], the output transformation ratio of the switch capacitor converter module is 3:1.

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] The output adjustable switching capacitor converter of the present invention, the switching switch tube is controlled by a clock control signal, and the purpose of adjusting the output ratio can be achieved by only adjusting the duty cycle of the clock control signal to control the switching of the switching switch tube. It has the advantages of miniaturization and lightness, and can realize two different output ratios at the same time. The control method is simple, easy to operate, and also convenient for expansion and cascading between switching capacitor converter modules.

[0018] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present invention more obvious and easy to understand, the following specifically cites a preferred embodiment and describes it in detail with the accompanying drawings as follows. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 is a structural schematic diagram of a switched capacitor converter with adjustable output provided by an embodiment of the present invention;

[0020] Figure 2 is a schematic structural diagram of a switched capacitor converter module provided by an embodiment of the present invention;

[0021] Figure 3 is an equivalent circuit structure diagram of a switched capacitor converter module provided by an embodiment of the present invention in a 2:1 working mode;

[0022] Figure 4This is a timing diagram of the gating operation of the switched capacitor converter module provided by an embodiment of the present invention in a 2:1 operation mode;

[0023] Figure 5 is an equivalent circuit structure diagram of a switched capacitor converter module provided by an embodiment of the present invention in a 3:1 working mode;

[0024] Figure 6 This is a timing diagram of the gating operation of the switch capacitor converter module provided by an embodiment of the present invention in a 3:1 operation mode. DETAILED DESCRIPTION

[0025] In order to further explain the technical means and effects adopted by the present invention to achieve the predetermined invention purpose, a switched capacitor converter with adjustable output proposed according to the present invention is described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0026] The above and other technical contents, features and effects of the present invention are clearly presented in the following detailed description of the specific implementation modes in conjunction with the accompanying drawings. Through the description of the specific implementation modes, the technical means and effects adopted by the present invention to achieve the predetermined purpose can be more deeply and specifically understood. However, the attached drawings are only for reference and explanation purposes and are not used to limit the technical solutions of the present invention.

[0027] Embodiment 1

[0028] In order to meet the requirements of miniaturization and integration of switched capacitor converters in power supply systems and avoid the use of large inductors, while also avoiding the use of a large number of switches for switching, this embodiment provides a switched capacitor converter with adjustable output, such as Figure 1 and Figure 2 As shown, Figure 1 is a structural schematic diagram of a switched capacitor converter with adjustable output provided by an embodiment of the present invention; Figure 2 It is a structural schematic diagram of a switched capacitor converter module provided in an embodiment of the present invention.

[0029] The output adjustable switching capacitor converter of this embodiment includes: a plurality of switching capacitor converter modules cascaded in sequence, and a coupling capacitor is connected between any two adjacent switching capacitor converter modules; wherein each switching capacitor converter module is provided with a switching switch tube, and the switching switch tube inputs a clock control signal; each switching capacitor converter module controls the switching switch tube through the duty cycle of the clock control signal to adjust the output transformation ratio.

[0030] Exemplarily, the output transformation ratio of the switched capacitor converter module is 2:1 or 3:1.

[0031] The principle is that, taking three cascaded switched capacitor converter modules as an example, the first switched capacitor converter module is cascaded with the second switched capacitor converter module through a coupling capacitor Co1, the second switched capacitor converter module is cascaded with the third switched capacitor converter module through a coupling capacitor Co2, and the input of the previous switched capacitor converter module is used as the output of the next switched capacitor converter module. The circuit structures of the three cascaded switched capacitor converter modules are all consistent, and each single switched capacitor converter module can realize the output ratio of the DC-DC input power supply, that is, the output voltage of the DC-DC input power supply is converted into a voltage output at a ratio of 2:1 or 3:1. A switching switch tube is provided in each switched capacitor converter module, and the switching switch tube in each switched capacitor converter module is controlled by a separate clock control signal. The switching of the switching switch tube is controlled by adjusting the duty cycle of the clock control signal, thereby realizing different output ratios. In other words, two different output ratios can be obtained only by controlling the key hardware, that is, by controlling the duty cycle of the clock control signal input to the switching switch tube.

[0032] In this embodiment, the switching transistor is an NMOS transistor. Specifically, each switch capacitor converter module includes: an NMOS transistor M1, which is used as a switching transistor and inputs a clock control signal.

[0033] like Figure 2 As shown, in this embodiment, each switch capacitor converter module further includes: NMOS transistor MN1, NMOS transistor MN2, NMOS transistor MN3, diode DN1, diode DN2, diode DN3, capacitor CN1, capacitor CN2 and capacitor CN3;

[0034] Among them, the drain end of the NMOS tube MN1 is connected to the positive electrode of the input power supply VCC, and the source end of the NMOS tube MN1 is respectively connected to the drain end of the NMOS tube MN3 and the first plate of the capacitor CN1; the drain end of the NMOS tube MN2 is respectively connected to the second plate of the capacitor CN1 and the source end of the NMOS tube M1, and the source end of the NMOS tube MN2 is connected to the negative electrode of the input power supply VCC; the drain end of the NMOS tube M1 is respectively connected to the source end of the NMOS tube MN3, the cathode of the diode DN1 and the first plate of the capacitor CN3; the anode of the diode DN1 is respectively connected to the first plate of the capacitor CN2 and the cathode of the diode DN2; the anode of the diode DN2 is respectively connected to the second plate of the capacitor CN3 and the cathode of the diode DN3; the source end of the NMOS tube MN2, the second plate of the capacitor CN2 and the anode of the diode DN3 are all grounded.

[0035] Further, such as Figure 1 and Figure 2As shown, the output adjustable switched capacitor converter of this embodiment also includes: a resistor Ro, a capacitor Co and an inductor Lo; the resistor Ro, the capacitor Co and the inductor Lo are respectively connected to the last switched capacitor converter module in a plurality of switched capacitor converter modules cascaded in sequence; wherein the first end of the inductor Lo is connected to the drain end of the NMOS tube M1; the second end of the inductor Lo is respectively connected to the first plate of the capacitor Co and the first end of the resistor Ro; the second plate of the capacitor Co and the second end of the resistor Ro are both grounded. Exemplarily, the resistor Ro is a virtual load, which can be implemented by a resistor or other resistive devices, such as a load that appears as a resistor.

[0036] For example, the diode DN1 and the diode DN2 can also be set as switch tubes, but since more control timings need to be added after adding the switch tubes, as in this embodiment, Figure 2 The circuit structure of the switched capacitor converter module shown in is a preferred implementation.

[0037] It is worth noting that the output adjustable switched capacitor converter of this embodiment realizes voltage conversion by alternating charging and discharging of capacitors and switching tubes. This conversion method avoids the magnetic energy conversion process in traditional transformers, thereby reducing energy loss. Compared with traditional voltage conversion devices based on resistor division, transformer conversion, low-dropout linear regulator (Low-dropout Regulator, LDO), etc., the efficiency of voltage conversion is improved.

[0038] Since magnetic components are prone to cause magnetic field changes during the switching process, electromagnetic interference is generated. In this embodiment, magnetic components such as inductors and transformers are removed from the switch capacitor converter module, thereby reducing the electromagnetic interference that these components may generate. In contrast, the switch capacitor converter module of this embodiment mainly relies on capacitors and switch tubes for voltage conversion, and the electromagnetic interference generated by these components is relatively small. In addition, it should be noted that after several switch capacitor converter modules are cascaded, an inductor Lo is provided at the output end of the last switch capacitor converter module to smooth the output and reduce the voltage ripple. Since the inductor only plays the role of smoothing the output, its size is also small. Capacitors CN1, CN2 and CN3 are all used for charging and discharging flying capacitors; capacitor Co is used for inter-stage decoupling and voltage stabilization, and enhances the stability of the circuit through filtering.

[0039] Exemplarily, the NMOS tube MN1 inputs a first PWM control signal, and the NMOS tubes MN2 and MN3 both input a second PWM control signal; wherein the first PWM (Pulse width modulation) control signal has the same frequency as the second PWM control signal, and their timings are complementary.

[0040] Exemplarily, the duty cycle of the first PWM control signal and the second PWM control signal are both 50%.

[0041] It can be understood that, in several switched capacitor converter modules cascaded in sequence, the switch tubes include: NMOS tube MN1, NMOS tube MN2 and NMOS tube MN3, and the NMOS tube MN1 in each switched capacitor converter module is controlled by the first PWM control signal, and the NMOS tube MN2 and NMOS tube MN3 in each switched capacitor converter module are controlled by the second PWM control signal.

[0042] like Figure 3 As shown, Figure 3 It is an equivalent circuit structure diagram of the switched capacitor converter module provided by an embodiment of the present invention in a 2:1 working mode.

[0043] When the duty cycle of the clock control signal is (0, 0.5], the output ratio of the switched capacitor converter module is 2:1, that is, the voltage output by the switched capacitor converter module is 1 / 2 of the output voltage of the input power supply.

[0044] For ease of understanding, it is taken as an example that the switched capacitor converter module works alone, and the output end of the switched capacitor converter module is respectively connected to a resistor Ro, a capacitor Co, and an inductor Lo.

[0045] Specifically, the equivalent circuit structure of the switched capacitor converter module of this embodiment in the 2:1 working mode is as follows: the NMOS tube M1 is equivalent to the diode D1, the source end of the NMOS tube M1 is the anode of the diode D1, and the drain end of the NMOS tube M1 is the cathode of the diode D1; the drain end of the NMOS tube MN1 is connected to the positive electrode of the input power supply VCC, and the source end of the NMOS tube MN1 is respectively connected to the drain end of the NMOS tube MN3 and the first plate of the capacitor CN1; the drain end of the NMOS tube MN2 is respectively connected to the second plate of the capacitor CN1 and the anode of the diode D1, and the source end of the NMOS tube MN2 is connected to the positive electrode of the input power supply VCC. The cathode of the diode D1 is respectively connected to the source end of the NMOS tube MN3, the cathode of the diode DN1, the first plate of the capacitor CN3 and the first end of the inductor Lo; the anode of the diode DN1 is respectively connected to the first plate of the capacitor CN2 and the cathode of the diode DN2; the anode of the diode DN2 is respectively connected to the second plate of the capacitor CN3 and the cathode of the diode DN3; the second end of the inductor Lo is respectively connected to the first plate of the capacitor Co and the first end of the resistor Ro; the source end of the NMOS tube MN2, the second plate of the capacitor CN2, the anode of the diode DN3, the second plate of the capacitor Co and the second end of the resistor Ro are all grounded.

[0046] Further, such as Figure 4 As shown, Figure 4This is a timing diagram of the gating operation of the switched capacitor converter module provided by an embodiment of the present invention in a 2:1 operation mode.

[0047] The gate switch of the switch capacitor converter module of this embodiment in the 2:1 working mode includes: NMOS tube MN1, NMOS tube MN2, NMOS tube MN3 and NMOS tube M1, wherein NMOS tube MN1 is controlled by the first PWM control signal, NMOS tube MN2 and NMOS tube MN3 are both controlled by the second PWM control signal, and the first PWM control signal has the same frequency and complementary timing, and is provided by an external isolated driver chip. The duty ratio of the first PWM control signal and the second PWM control signal is 50%. NMOS tube M1 is controlled by a clock control signal, and its duty ratio is (0, 0.5].

[0048] like Figure 5 As shown, Figure 5 It is an equivalent circuit structure diagram of the switched capacitor converter module provided by an embodiment of the present invention in a 3:1 working mode.

[0049] When the duty cycle of the clock control signal is (0.5, 1], the output ratio of the switched capacitor converter module is 3:1, that is, the voltage output by the switched capacitor converter module is 1 / 3 of the output voltage of the input power supply.

[0050] Similarly, for ease of understanding, the output ends of the switched capacitor converter module are respectively connected to a resistor Ro, a capacitor Co, and an inductor Lo. Specifically, the equivalent circuit structure of the switched capacitor converter module of this embodiment in the 3:1 working mode is as follows: the NMOS tube M1 is equivalent to a wire, and the two ends of the wire are respectively connected to the second plate of the capacitor CN1 and the source end of the NMOS tube MN3; the drain end of the NMOS tube MN1 is connected to the positive electrode of the input power supply VCC, and the source end of the NMOS tube MN1 is respectively connected to the drain end of the NMOS tube MN3 and the first plate of the capacitor CN1; the drain end of the NMOS tube MN2 is connected to the second plate of the capacitor CN1, and the source end of the NMOS tube MN2 is connected to the negative electrode of the input power supply VCC; The source end of the tube MN3 is respectively connected to the cathode of the diode DN1, the first plate of the capacitor CN3 and the first end of the inductor Lo; the anode of the diode DN1 is respectively connected to the first plate of the capacitor CN2 and the cathode of the diode DN2; the anode of the diode DN2 is respectively connected to the second plate of the capacitor CN3 and the cathode of the diode DN3; the second end of the inductor Lo is respectively connected to the first plate of the capacitor Co and the first end of the resistor Ro; the source end of the NMOS tube MN2, the second plate of the capacitor CN2, the anode of the diode DN3, the second plate of the capacitor Co and the second end of the resistor Ro are all grounded.

[0051] Further, such as Figure 6 As shown, Figure 6This is a timing diagram of the gating operation of the switch capacitor converter module provided by an embodiment of the present invention in a 3:1 operation mode.

[0052] The gate switch of the switch capacitor converter module of this embodiment in the 3:1 working mode includes: NMOS tube MN1, NMOS tube MN2, NMOS tube MN3 and NMOS tube M1, wherein NMOS tube MN1 is controlled by the first PWM control signal, NMOS tube MN2 and NMOS tube MN3 are both controlled by the second PWM control signal, and the first PWM control signal has the same frequency and complementary timing, and is provided by an external isolated driver chip. The duty ratio of the first PWM control signal and the second PWM control signal is 50%. NMOS tube M1 is controlled by a clock control signal, and its duty ratio is (0.5, 1].

[0053] The output adjustable switching capacitor converter of the present invention, the switching switch tube is controlled by a clock control signal, and the purpose of adjusting the output ratio can be achieved by only adjusting the duty cycle of the clock control signal to control the switching of the switching switch tube. It has the advantages of miniaturization and lightness, and can realize two different output ratios at the same time. The control method is simple, easy to operate, and also convenient for expansion and cascading between switching capacitor converter modules.

[0054] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply that there is any such actual relationship or order between these entities or operations. Moreover, the term "include", "comprise" or any other variant is intended to cover non-exclusive inclusion, so that the article or device including a series of elements includes not only those elements, but also other elements that are not explicitly listed. In the absence of more restrictions, the elements defined by the sentence "including one..." do not exclude the existence of other identical elements in the article or device including the elements. "Connect" or "connected" and similar words are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. The orientation or position relationship indicated by "up", "down", "left", "right", etc. is based on the orientation or position relationship shown in the accompanying drawings, which is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation of the present invention.

[0055] The above contents are further detailed descriptions of the present invention in combination with specific preferred embodiments, and it cannot be determined that the specific implementation of the present invention is limited to these descriptions. For ordinary technicians in the technical field to which the present invention belongs, several simple deductions or substitutions can be made without departing from the concept of the present invention, which should be regarded as falling within the protection scope of the present invention.

Claims

1. A switched capacitor converter with adjustable output, characterized in that: include: A plurality of switched capacitor converter modules cascaded in sequence, with a coupling capacitor connected between any two adjacent switched capacitor converter modules; Each of the switched capacitor converter modules is provided with a switching switch tube, and the switching switch tube inputs a clock control signal; each of the switched capacitor converter modules controls the switching switch tube through the duty cycle of the clock control signal to adjust the output transformation ratio.

2. The output adjustable switched capacitor converter according to claim 1, characterized in that: The switching tube is an NMOS tube.

3. The output adjustable switched capacitor converter according to claim 1, characterized in that: Each of the switch capacitor converter modules includes: an NMOS tube M1, which serves as the switching switch tube and inputs the clock control signal.

4. The output adjustable switched capacitor converter according to claim 3, characterized in that: Each of the switch capacitor converter modules further includes: an NMOS transistor MN1, an NMOS transistor MN2, an NMOS transistor MN3, a diode DN1, a diode DN2, a diode DN3, a capacitor CN1, a capacitor CN2, and a capacitor CN3; The drain end of the NMOS tube MN1 is connected to the positive electrode of the input power supply VCC, and the source end of the NMOS tube MN1 is connected to the drain end of the NMOS tube MN3 and the first electrode plate of the capacitor CN1 respectively; The drain end of the NMOS tube MN2 is connected to the second electrode plate of the capacitor CN1 and the source end of the NMOS tube M1 respectively, and the source end of the NMOS tube MN2 is connected to the negative electrode of the input power supply VCC; The drain end of the NMOS tube M1 is respectively connected to the source end of the NMOS tube MN3, the cathode of the diode DN1 and the first plate of the capacitor CN3; The anode of the diode DN1 is connected to the first plate of the capacitor CN2 and the cathode of the diode DN2 respectively; The anode of the diode DN2 is connected to the second plate of the capacitor CN3 and the cathode of the diode DN3 respectively; The source end of the NMOS transistor MN2, the second electrode plate of the capacitor CN2 and the anode of the diode DN3 are all grounded.

5. The output adjustable switched capacitor converter according to claim 4, characterized in that: The output adjustable switched capacitor converter also includes: a resistor Ro, a capacitor Co and an inductor Lo; The resistor Ro, the capacitor Co and the inductor Lo are respectively connected to the last switch capacitor converter module in a plurality of switch capacitor converter modules that are cascaded in sequence; The first end of the inductor Lo is connected to the drain end of the NMOS tube M1; the second end of the inductor Lo is connected to the first plate of the capacitor Co and the first end of the resistor Ro respectively; The second electrode plate of the capacitor Co and the second end of the resistor Ro are both grounded.

6. The output adjustable switched capacitor converter according to claim 4, characterized in that: The NMOS tube MN1 inputs a first PWM control signal, and the NMOS tube MN2 and the NMOS tube MN3 both input a second PWM control signal; The first PWM control signal and the second PWM control signal have the same frequency and complementary timing.

7. The output adjustable switched capacitor converter according to claim 6, characterized in that: The duty cycles of the first PWM control signal and the second PWM control signal are both 50%.

8. The output adjustable switched capacitor converter according to claim 4, characterized in that: The output transformation ratio of the switch capacitor converter module is 2:1 or 3:

1.

9. The output adjustable switched capacitor converter according to claim 8, characterized in that: When the duty cycle of the clock control signal is (0, 0.5], the output transformation ratio of the switch capacitor converter module is 2:

1.

10. The output adjustable switched capacitor converter according to claim 8, characterized in that: When the duty cycle of the clock control signal is (0.5, 1], the output ratio of the switched capacitor converter module is 3:1.

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