Control circuit and control method for switched capacitor converter

Abstract

The application discloses a control circuit and a control method of a switched capacitor converter. The control circuit adjusts the voltage across the flying capacitor to be consistent with the output voltage by using a small pull-down current, so that the voltage across the flying capacitor is equal to the output voltage before the switched capacitor converter starts the formal voltage conversion. The control circuit of the switched capacitor converter can control the voltage of the circuit before the formal voltage conversion of the switched capacitor converter, so that the components of the circuit are protected from the impact of a large current and are not easily damaged.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of power electronics, more particularly, to a control circuit and control method of a switched capacitor converter. BACKGROUND

[0002] The switched capacitor converter is a kind of DC-DC conversion system, which converts the received input voltage into the desired output voltage, which can adjust the output voltage to be the multiple (such as 2 times) of the input voltage output or adjust the output voltage to be the fraction (such as 1 / 2) of the input voltage output, such as Figure 1 As shown in a common switched capacitor converter, including the switching tube Q1-Q4 connected between the reference ground and the input voltage, the switching tube Q1 and the switching tube Q3 and the switching tube Q2 and the switching tube Q4 are complementary on and off, the first end of the flying capacitor CF is connected to the common node of the switching tube Q1 and the switching tube Q2, the second end is connected to the common node of the switching tube Q3 and the switching tube Q4, one end of the output capacitor C1 is connected to the reference ground, and the voltage of the other end is the output voltage Vo.

[0003] In the case of 2:1 step-down conversion of the switched capacitor converter, the duty cycle of the switching tube is about 0.5, before the start-up of the switched capacitor converter, the voltage across the flying capacitor and the output voltage is about half of the input voltage, but in the actual circuit, due to the short circuit fault of the circuit, the voltage across the flying capacitor or the output voltage is not equal to half of the input voltage, in this case, if the switching tube is directly started to connect the input voltage, there may be a relatively large instantaneous current flowing through the switching tube or the flying capacitor, affecting the reliability of the circuit device work. SUMMARY

[0004] Therefore, the purpose of the present application is to provide a control circuit and control method of a switched capacitor converter, to solve the technical problem of the uncontrolled voltage of the switched capacitor converter causing damage to the devices in the circuit.

[0005] The application provides a control circuit of a switched capacitor converter, the switched capacitor converter comprising a first switch, a second switch, a third switch and a fourth switch connected in sequence between a reference ground and an input voltage, a flying capacitor and an output capacitor, a first end of the flying capacitor being connected to a common node of the first switch and the second switch, a second end of the flying capacitor being connected to a common node of the third switch and the fourth switch, a first end of the output capacitor being connected to the reference ground, and a second end of the output capacitor providing a voltage as an output voltage of the switched capacitor converter, the control circuit comprising a switch signal generation circuit and an adjusting circuit, the switch signal generation circuit being configured to generate switch control signals for controlling the first switch, the second switch, the third switch and the fourth switch, the adjusting circuit being configured to receive voltages at the first end and the second end of the flying capacitor, and to pull down the voltages at the first end and the second end of the flying capacitor by a pull-down signal, so as to adjust the voltages at the two ends of the flying capacitor to be consistent with the output voltage, and the switch signal generation circuit being configured to control the first switch, the second switch, the third switch and the fourth switch to be all turned off, and when the voltages at the two ends of the flying capacitor are adjusted to be consistent with the output voltage, the switch signal generation circuit is configured to control the first switch, the second switch, the third switch and the fourth switch to start working to perform voltage conversion.

[0006] Preferably, the pull-down signal is a current signal with a current value in a preset range, and the preset range is greater than zero and less than 1A.

[0007] Preferably, the adjusting circuit adjusts the voltage at the second end of the flying capacitor to be at the same potential as the voltage at the second end of the output capacitor, and then the switch signal generation circuit controls the third switch to be turned on, and the adjusting circuit adjusts the voltage at the first end of the flying capacitor to be at the same potential as the reference ground.

[0008] Preferably, the adjusting circuit pulls down the voltage at the second end of the flying capacitor to be at the same potential as the voltage at the second end of the output capacitor by the pull-down signal, and the adjusting circuit pulls down the voltage at the first end of the flying capacitor to be at the same potential as the reference ground by the pull-down signal.

[0009] Preferably, the adjusting circuit comprises a switch circuit, the switch circuit having the second end of the flying capacitor and the second end of the output capacitor connected thereto, and after the voltage at the second end of the flying capacitor is pulled down to be at the same potential as the voltage at the second end of the output capacitor, the switch circuit has the first end of the flying capacitor and the reference ground connected thereto, and the working current of the switch circuit serves as the pull-down signal.

[0010] Preferably, the switch circuit comprises any one of a switch, a resistor and a switch connected in series, and a switch and a current source connected in series.

[0011] Preferably, the pull-down signal comprises a first pull-down signal and a second pull-down signal, the regulating circuit pulls down the second end voltage of the flying capacitor to the same potential as the second end voltage of the output capacitor through the first pull-down signal, and the regulating circuit pulls down the first end voltage of the flying capacitor to the same potential as the reference ground through the second pull-down signal.

[0012] Preferably, the regulating circuit comprises a first switch circuit and a second switch circuit, the first switch circuit has the second end of the flying capacitor and the second end of the output capacitor connected across the first switch circuit, and the second switch circuit has the first end of the flying capacitor and the reference ground connected across the second switch circuit; the working current of the first switch circuit serves as the first pull-down signal, and the working current of the second switch circuit serves as the second pull-down signal.

[0013] Preferably, the first switch circuit comprises any one of a switch tube, a resistor and a switch tube connected in series, and a switch tube and a current source connected in series, and the second switch circuit comprises any one of a switch tube, a resistor and a switch tube connected in series, and a switch tube and a current source connected in series.

[0014] Preferably, the control circuit further comprises a driving voltage circuit, the driving voltage circuit comprises a bootstrap capacitor, the bootstrap capacitor provides a driving voltage to the logic and driving circuit in the control circuit, the upper plate of the bootstrap capacitor is connected to an input voltage through a diode, the lower plate of the bootstrap capacitor is connected to a pulse signal through a switch, the diode is turned on, the bootstrap capacitor is charged by the input voltage, the switch is turned on to pull down the voltage at the lower plate end of the bootstrap capacitor by a first signal, and when the voltage at the lower plate end of the bootstrap capacitor is pulled down to zero potential, the first switch tube, the second switch tube, the third switch tube and the fourth switch tube start to work to perform voltage conversion under the control of the switch signal generation circuit.

[0015] Preferably, the first signal is a current signal with a current value in a preset range, and the preset range is greater than zero and less than 1A.

[0016] Preferably, the switch capacitor converter comprises two-phase switch capacitor circuits with the same structure, the first switch tube, the second switch tube, the third switch tube, the fourth switch tube and the flying capacitor constitute a first-phase switch capacitor circuit, and the frequency of the pulse signal is twice the switching working frequency of the switch capacitor circuit.

[0017] Preferably, the control circuit further comprises a detection circuit, after the first switch and the third switch are turned off, the switch signal generation circuit generates a second switch control signal to control the second switch to be turned on, the detection circuit detects the second end voltage of the flying capacitor, and detects the voltage difference between the second end voltage of the flying capacitor and the input voltage, when the absolute value of the voltage difference between the two is within a preset range, the switch signal generation circuit generates a fourth switch control signal to control the fourth switch to be turned on.

[0018] In a second aspect, the application provides a control method of a switched capacitor converter, the switched capacitor converter comprising a first switch, a second switch, a third switch and a fourth switch connected in sequence between a reference ground and an input voltage, and a flying capacitor and an output capacitor, a first end of the flying capacitor being connected to a common node of the first switch and the second switch, a second end of the flying capacitor being connected to a common node of the third switch and the fourth switch, a first end of the output capacitor being connected to the reference ground, and a second end voltage of the output capacitor being an output voltage of the switched capacitor converter, the method comprising the steps of: turning off the first switch, the second switch, the third switch and the fourth switch; pulling down the first end voltage and the second end voltage of the flying capacitor by a pull-down signal to adjust the voltage across the flying capacitor to be consistent with the output voltage; and after the voltage across the flying capacitor is adjusted to be consistent with the output voltage, the switch signal generation circuit controls the first switch, the second switch, the third switch and the fourth switch to start working to perform voltage conversion.

[0019] Preferably, the pull-down signal is a current signal with a current value within a preset range, and the preset range is greater than zero and less than 1A.

[0020] Preferably, the step of pulling down the first end voltage and the second end voltage of the flying capacitor by the pull-down signal to adjust the voltage across the flying capacitor to be consistent with the output voltage specifically comprises the steps of: adjusting the second end voltage of the flying capacitor to be at the same potential as the second end voltage of the output capacitor by the pull-down signal, the switch signal generation circuit controls the third switch to be turned on, and adjusting the first end voltage of the flying capacitor to be at the same potential as the reference ground by the pull-down signal.

[0021] Preferably, the method further comprises: providing a driving voltage by a bootstrap capacitor, the upper plate of the bootstrap capacitor is connected to the input voltage through a diode, the lower plate of the bootstrap capacitor is connected to a pulse signal through a switch, the first signal is a current signal with a current value within a preset range, the diode is turned on, the bootstrap capacitor is charged by the input voltage, and the switch is turned on to pull down the lower plate end voltage of the bootstrap capacitor by the first signal, when the lower plate end voltage is pulled down to zero potential, the first switch, the second switch, the third switch and the fourth switch are controlled to start working to perform voltage conversion.

[0022] Preferably, after the first switch tube and the third switch tube are turned off, the second switch tube is controlled to be turned on, the voltage at the second end of the flying capacitor is detected, and the voltage difference between the second end voltage of the flying capacitor and the input voltage is detected. When the absolute value of the voltage difference between the two is within a preset range, the fourth switch tube is controlled to be turned on.

[0023] With the circuit structure of the present invention, a regulating circuit uses a relatively low current to adjust the voltage across the flying capacitor to be equal to the output voltage. This ensures that the voltage across the flying capacitor is consistent with the output voltage before the switched capacitor converter officially starts operating. The control circuit of the switched capacitor converter of the present invention allows the circuit voltage to be controlled before the switched capacitor converter officially starts operating, protecting the circuit components from high current surges and minimizing damage to the components. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 A topological diagram of an existing switched capacitor converter;

[0025] Figure 2 is a block diagram of a control circuit of a switched capacitor converter according to the present invention;

[0026] Figure 3 A circuit block diagram of a regulating circuit for a switched capacitor converter according to the present invention;

[0027] Figure 4 for Figure 3 Specific circuit diagram of the regulating circuit;

[0028] Figure 5 is a specific circuit diagram of a driving voltage circuit according to the present invention;

[0029] Figure 6 FIG. 4 is a specific circuit diagram of a detection circuit according to the present invention. DETAILED DESCRIPTION

[0030] The preferred embodiments of the present invention are described in detail below with reference to the accompanying drawings, but the present invention is not limited to these embodiments and covers any substitution, modification, equivalent method and solution made within the spirit and scope of the present invention.

[0031] In order to make the public have a thorough understanding of the present invention, specific details are described in detail in the following preferred embodiments of the present invention, but those skilled in the art can also fully understand the present invention without description of these details.

[0032] The present invention is described in more detail in the following paragraphs by way of example with reference to the accompanying drawings. It should be noted that the drawings are simplified and not to exact proportions, and are only used for the purpose of conveniently and clearly illustrating the embodiments of the present invention.

[0033] Reference Figure 2 is a block diagram of a control circuit of a switched capacitor converter according to the present application, Figure 3 is a circuit diagram of a regulating circuit of a switched capacitor converter according to the present application, and Figure 4 is Figure 3 a detailed circuit diagram of the regulating circuit. The switched capacitor converter according to the present application comprises a first switch Q1, a second switch Q2, a third switch Q3 and a fourth switch Q4 connected in sequence between a reference ground and an input voltage, a flying capacitor CF and an output capacitor Cl, a first end of the flying capacitor CF is connected to a common node of the first switch Q1 and the second switch Q2, a second end of the flying capacitor CF is connected to a common node of the third switch Q3 and the fourth switch Q3, a first end of the output capacitor Cl is connected to the reference ground, and a second end of the output capacitor Cl outputs a voltage as an output voltage Vo of the switched capacitor converter. In the embodiment of the present application, the switched capacitor converter is a 2:1 step-down converter, duty cycles of the switches are approximately 0.5, the first switch Q1 and the third switch Q3 are complementary to the second switch Q2 and the fourth switch Q4, and the first switch Q1, the second switch Q2, the third switch Q3 and the fourth switch Q4 are all N-type MOS transistors.

[0034] As shown in Figure 2 , the control circuit of the switched capacitor converter comprises a switch signal generating circuit and a logic and driving circuit. The switch signal generating circuit generates switch control signals for controlling the first switch Q1, the second switch Q2, the third switch Q3 and the fourth switch Q4 according to an output feedback signal Vfb, such as a first switch control signal for controlling the first switch Q1 to be on or off, a second switch control signal for controlling the second switch Q2 to be on or off, and a third switch control signal for controlling the third switch Q3 to be on or off. The logic and driving circuit receives the switch control signals of the switches and a driving voltage, and generates corresponding switch driving signals according to the switch control signals to control the corresponding switches to be on or off.

[0035] In one example, reference Figure 3The control circuit includes an adjusting circuit receiving the first end voltage and the second end voltage of the flying capacitor and pulling down the first end voltage and the second end voltage of the flying capacitor by a pull-down signal to adjust the voltage across the flying capacitor to be consistent with the output voltage, where the pull-down signal is a current signal with a current value in a preset range greater than zero and less than 1A, such as a pull-down current value of 800mA, 500mA or 100mA. Before the switch capacitor converter starts to work formally, the switch signal generation circuit controls the first switch tube, the second switch tube, the third switch tube and the fourth switch tube to be all turned off, and after the voltage across the flying capacitor is adjusted to be consistent with the output voltage, the switch signal generation circuit controls the first switch tube, the second switch tube, the third switch tube and the fourth switch tube to start to work to perform voltage conversion.

[0036] For example, the adjusting circuit adjusts the second end voltage of the flying capacitor to be at the same potential as the second end voltage of the output capacitor, and then the switch signal generation circuit controls the third switch tube to be turned on, and the adjusting circuit adjusts the first end voltage of the flying capacitor to be at the same potential as the reference ground. In this way, the voltage across the flying capacitor is adjusted to be consistent with the output voltage, where the consistency means that the voltage CVF across the flying capacitor is equal to or close to the output voltage. In the above manner, before the switch capacitor converter starts to work formally, the voltage across the flying capacitor is adjusted by a smaller current signal to make the voltage across the flying capacitor consistent with the output voltage, so that the voltage of the circuit can be controlled before the switch capacitor converter starts to work formally, and the components of the circuit are protected from large current impact and are less likely to be damaged.

[0037] As shown in FIG. 1, Figure 4 For example, the pull-down signal includes a first pull-down signal and a second pull-down signal, the adjusting circuit pulls down the second end voltage of the flying capacitor to be at the same potential as the second end voltage of the output capacitor by the first pull-down signal, and the adjusting circuit pulls down the first end voltage of the flying capacitor to be at the same potential as the reference ground by the second pull-down signal. Specifically, the adjusting circuit includes a first switch circuit and a second switch circuit, the first switch circuit includes any one of a switch tube, a resistor and a switch tube in series, and a switch tube and a current source in series, and the second switch circuit includes any one of a switch tube, a resistor and a switch tube in series, and a switch tube and a current source in series. Figure 4In the embodiment, the first switch circuit takes the resistor R1, the resistor R2 and the switch tube M1 in series as an example, and the second switch circuit takes the switch tube M2 and the current source I1 in series as an example. The two ends of the first switch circuit are connected to the second end of the flying capacitor to receive the voltage CFP and the second end of the output capacitor to receive the voltage Vo. The two ends of the second switch circuit are connected to the first end of the flying capacitor to receive the voltage CFN and the reference ground. The working current of the first switch circuit is the first pull-down signal, and the working current of the second switch circuit is the second pull-down signal. Here, the current of the first pull-down signal and the second pull-down signal ranges from greater than zero to less than 1A.

[0038] As shown in the combination Figure 3 And Figure 4 When the voltage across the flying capacitor CF is higher than the output voltage, the flying capacitor CF is discharged through the body diode of the first switch tube Q1. When the voltage across the flying capacitor CF is lower than the output voltage, the voltage CFP of the flying capacitor is pulled down by the first pull-down signal. In this way, the voltage CFP of the flying capacitor can be pulled down to the same voltage as the second end voltage of the output capacitor. Then, the switch signal generation circuit controls the third switch tube to be turned on, and the first end voltage of the flying capacitor is pulled down to the same potential as the reference ground through the second pull-down signal. In this way, the voltage across the flying capacitor can be adjusted to be consistent with the output voltage. Here, the third switch tube is turned on to ensure that the second end voltage of the flying capacitor is kept at the same potential as the second end voltage of the output capacitor. At this time, the second end voltage of the flying capacitor is no longer pulled down by a small current.

[0039] In another example, the adjustment circuit pulls down the second end voltage of the flying capacitor to the same potential as the second end voltage of the output capacitor through the pull-down signal, and pulls down the first end voltage of the flying capacitor to the same potential as the reference ground through the pull-down signal. The adjustment circuit includes a switch circuit, which includes any one of a switch tube, a resistor and a switch tube in series, a switch tube and a current source in series, and the like. The two ends of the switch circuit are connected to the second end of the flying capacitor and the second end of the output capacitor, so as to pull down the second end voltage of the flying capacitor to the same potential as the second end voltage of the output capacitor. After that, the two ends of the switch circuit are connected to the first end of the flying capacitor and the reference ground. The working current of the switch circuit is the pull-down signal. In this embodiment, the second end voltage of the flying capacitor is pulled down by the pull-down signal first, and then the connection point of the switch circuit is switched, and the first end voltage of the flying capacitor is pulled down by the pull-down signal. This embodiment can save the structure of the switch circuit and simplify the circuit.

[0040] Reference Figure 5The control circuit further comprises a driving voltage circuit, the driving voltage circuit comprises a bootstrap capacitor CBST, the bootstrap capacitor CBST provides a driving voltage to logic and driving circuits in the control circuit, the logic and driving circuits drive the fourth switch tube according to the driving voltage, the upper plate of the bootstrap capacitor is connected to the input voltage through a diode D1, the lower plate of the bootstrap capacitor is connected to a pulse signal P1 through a switch M3, the diode D1 is turned on, the bootstrap capacitor is charged through the input voltage Vin, the switch M3 is turned on to pull down the voltage at the lower plate end of the bootstrap capacitor with the first signal, when the voltage at the lower plate end is pulled down to zero potential, the first switch tube, the second switch tube, the third switch tube and the fourth switch tube start to work to perform voltage conversion under the control of the switch signal generation circuit. Illustratively, the first signal is a current signal with a current value in a preset range, and the preset range is greater than zero and less than 1A. Here, the driving voltage circuit further prevents the input voltage from being reversed by the diode D2, and the switch M3 is a high-voltage NMOS transistor. When the voltage at the lower plate end is pulled down to zero potential, it indicates that the bootstrap capacitor CBST has been fully charged and can normally supply power, so that the first switch tube, the second switch tube, the third switch tube and the fourth switch tube start to work to perform voltage conversion, which can ensure stable power supply of the circuit. In the charging process of the bootstrap capacitor in the driving voltage circuit of the embodiment, the voltage at the lower plate is pulled down by a small current, which can prevent the bootstrap capacitor from being damaged by a large charging current in the case of bootstrap capacitor failure, such as short circuit. In the embodiment, the source voltage of the fourth switch tube is large, and a large driving voltage is required to drive the switch tube Q4 to work. The driving voltages of the other three switch tubes can be provided by the voltages at nodes such as point A or point B, and a separate driving circuit is not required. Of course, the driving voltages can also be provided by the driving voltage circuit of the embodiment.

[0041] Further, the switched capacitor converter comprises two-phase structure identical switched capacitor circuits, the first switch tube, the second switch tube, the third switch tube, the fourth switch tube and the flying capacitor constitute a first-phase switched capacitor circuit, and the frequency of the pulse signal is twice the switching working frequency of the switched capacitor circuit. To meet the power supply requirements of the two-phase switched capacitor circuits. The two-phase switched capacitor circuits share an output capacitor, and the output voltages of the two-phase switched capacitor circuits are each half of the input voltage. The ripples of the input voltages and the output voltages of the two phases are offset to each other, so that the ripples of the input voltage and the output voltage of the switched capacitor converter are smaller.

[0042] Reference Figure 6The control circuit further comprises a detection circuit. After the first switch tube and the third switch tube are turned off, the switch signal generation circuit generates a second switch control signal to turn on the second switch tube. The detection circuit detects the second end voltage of the flying capacitor and the voltage difference between the second end voltage of the flying capacitor and the input voltage. When the absolute value of the voltage difference is within a preset range, the switch signal generation circuit generates a fourth switch control signal to turn on the fourth switch tube. The preset range is 0-500 mA. Here, the second end voltage of the flying capacitor is greater than or equal to the difference between the input voltage and a fixed voltage and less than the sum of the input voltage and the fixed voltage. The fixed voltage can be set to any value within the range of 0-500 mA. In this way, whether the voltage across the flying capacitor is equal to the output voltage can be detected. When the two voltages are not equal, the input voltage can be adjusted according to the situation so that the two voltages are equal, and then the fourth switch tube is turned on, thereby protecting the switch tube from being damaged by a large current.

[0043] The above-described embodiments do not constitute a limitation on the protection scope of the technical solutions. Any modification, equivalent replacement and improvement made within the spirit and principles of the above-described embodiments shall be included in the protection scope of the technical solutions.

Claims

1. A control circuit of a switched capacitor converter, the switched capacitor converter comprising a first switch, a second switch, a third switch and a fourth switch connected in sequence between a reference ground and an input voltage, and a flying capacitor and an output capacitor, a first terminal of the flying capacitor being connected to a common node of the first switch and the second switch, a second terminal of the flying capacitor being connected to a common node of the third switch and the fourth switch, a first terminal of the output capacitor being connected to the reference ground, a second terminal of the output capacitor being connected to a common node of the second switch and the third switch, a voltage at the second terminal of the output capacitor being an output voltage of the switched capacitor converter, characterized in that, The control circuit of the switched capacitor converter comprises a switch signal generating circuit and a regulating circuit, The switch signal generating circuit is configured to generate switch control signals for controlling the first switch, the second switch, the third switch and the fourth switch, The regulating circuit receives the first end voltage and the second end voltage of the flying capacitor, and pulls down the first end voltage and the second end voltage of the flying capacitor through a pull-down signal to regulate the voltage across the flying capacitor to be consistent with the output voltage, wherein the regulating circuit regulates the second end voltage of the flying capacitor to be at the same potential as the second end voltage of the output capacitor, and then the switch signal generating circuit controls the third switch to be turned on, and the regulating circuit regulates the first end voltage of the flying capacitor to be at the same potential as the reference ground. The switch signal generating circuit controls the first switch, the second switch, the third switch and the fourth switch to be turned off, and after the voltage across the flying capacitor is regulated to be consistent with the output voltage, the switch signal generating circuit controls the first switch, the second switch, the third switch and the fourth switch to start working to perform voltage conversion.

2. The control circuit of a switched-capacitor converter according to claim 1, characterized in that, The pull-down signal is a current signal with a current value in a preset range, The preset range is greater than zero and less than 1A.

3. The control circuit of the switched capacitor converter according to claim 1, wherein The regulating circuit pulls down the second end voltage of the flying capacitor to be at the same potential as the second end voltage of the output capacitor through the pull-down signal, The regulating circuit pulls down the first end voltage of the flying capacitor to be at the same potential as the reference ground through the pull-down signal.

4. The control circuit of the switched capacitor converter according to claim 3, wherein The regulating circuit comprises a switch circuit, two ends of the switch circuit are connected to the second end of the flying capacitor and the second end of the output capacitor, after the second end voltage of the flying capacitor is pulled down to be at the same potential as the second end voltage of the output capacitor, the two ends of the switch circuit are connected to the first end of the flying capacitor and the reference ground, The working current of the switch circuit serves as the pull-down signal.

5. The control circuit of the switched capacitor converter according to claim 4, wherein The switch circuit comprises any one of a switch, a resistor and a switch connected in series, and a switch and a current source connected in series.

6. The control circuit of the switched capacitor converter according to claim 1, wherein The pull-down signal comprises a first pull-down signal and a second pull-down signal, The regulating circuit pulls down the second end voltage of the flying capacitor to be at the same potential as the second end voltage of the output capacitor through the first pull-down signal, The regulating circuit pulls down the first end voltage of the flying capacitor to be at the same potential as the reference ground through the second pull-down signal.

7. The control circuit of a switched-capacitor converter according to claim 6, characterized in that, The regulating circuit comprises a first switch circuit and a second switch circuit, Two ends of the first switch circuit are connected to the second end of the flying capacitor and the second end of the output capacitor, Two ends of the second switch circuit are connected to the first end of the flying capacitor and the reference ground. The working current of the first switch circuit is the first pull-down signal, and the working current of the second switch circuit is the second pull-down signal.

8. The control circuit of the switched capacitor converter according to claim 7, wherein, The first switch circuit comprises any one of a switch tube, a series connection of a resistor and a switch tube, and a series connection of a switch tube and a current source, The second switch circuit comprises any one of a switch tube, a series connection of a resistor and a switch tube, and a series connection of a switch tube and a current source.

9. The control circuit of a switched-capacitor converter according to claim 1, characterized in that, The control circuit further comprises a driving voltage circuit, The driving voltage circuit comprises a bootstrap capacitor, the bootstrap capacitor provides a driving voltage to logic and driving circuits in the control circuit, the upper plate of the bootstrap capacitor is connected to an input voltage through a diode, and the lower plate of the bootstrap capacitor is connected to a pulse signal through a switch, The diode is turned on, the bootstrap capacitor is charged by the input voltage, and the switch is turned on to pull down the voltage at the lower plate of the bootstrap capacitor to the first signal, When the voltage at the lower plate is pulled down to zero potential, the switch signal generation circuit controls the first switch tube, the second switch tube, the third switch tube and the fourth switch tube to start working to perform voltage conversion.

10. The control circuit of a switched-capacitor converter according to claim 9, characterized in that, The first signal is a current signal with a current value in a preset range, The preset range is greater than zero and less than 1A.

11. The control circuit of a switched-capacitor converter according to claim 9, wherein, The switched capacitor converter comprises two-phase switch capacitor circuits with the same structure, the first switch tube, the second switch tube, the third switch tube, the fourth switch tube and the flying capacitor constitute a first-phase switch capacitor circuit, The frequency of the pulse signal is twice the switching working frequency of the switch capacitor circuit.

12. The control circuit of a switched-capacitor converter according to claim 1, wherein, The control circuit further comprises a detection circuit, After the first switch tube and the third switch tube are turned off, the switch signal generation circuit generates a second switch control signal to control the second switch tube to be turned on, The detection circuit detects the voltage at the second end of the flying capacitor and detects the voltage difference between the voltage at the second end of the flying capacitor and the input voltage, When the absolute value of the voltage difference is in a preset range, the switch signal generation circuit generates a fourth switch control signal to control the fourth switch tube to be turned on.

13. A control method of a switched capacitor converter, the switched capacitor converter comprising a first switch, a second switch, a third switch and a fourth switch connected in sequence between a reference ground and an input voltage, and a flying capacitor and an output capacitor, a first terminal of the flying capacitor being connected to a common node of the first switch and the second switch, a second terminal of the flying capacitor being connected to a common node of the third switch and the fourth switch, a first terminal of the output capacitor being connected to the reference ground, a second terminal of the output capacitor being connected to a common node of the second switch and the third switch, a voltage at the second terminal of the output capacitor being an output voltage of the switched capacitor converter, characterized in that, The method comprises the steps of: turning off the first switch tube, the second switch tube, the third switch tube and the fourth switch tube; adjusting the voltage at the second end of the flying capacitor to the same potential as the voltage at the second end of the output capacitor through a pull-down signal, controlling the third switch tube to be turned on by the switch signal generation circuit, adjusting the voltage at the first end of the flying capacitor to the same potential as the reference ground through a pull-down signal to adjust the voltage across the flying capacitor to be consistent with the output voltage; after the voltage across the flying capacitor is adjusted to be consistent with the output voltage, the switch signal generation circuit controls the first switch tube, the second switch tube, the third switch tube and the fourth switch tube to start working to perform voltage conversion.

14. The control method of the switched capacitor converter according to claim 13, wherein, The pull-down signal is a current signal with a current value in a preset range, The preset range is greater than zero and less than 1A.

15. The control method of a switched-capacitor converter according to claim 13, wherein, Further comprising: providing a driving voltage through a bootstrap capacitor, An upper plate of a bootstrap capacitor is connected to an input voltage through a diode, and a lower plate of the bootstrap capacitor is connected to a pulse signal through a switch, The diode is turned on, the bootstrap capacitor is charged by the input voltage, and the switch is turned on to pull down the voltage at the lower plate of the bootstrap capacitor by a first signal, the first signal being a current signal with a current value within a preset range, After the voltage at the lower plate is pulled down to zero potential, the first switch, the second switch, the third switch, and the fourth switch are controlled to start working to perform voltage conversion.

16. The control method of the switched capacitor converter according to claim 13, wherein After the first switch and the third switch are turned off, the second switch is controlled to be turned on, The voltage at the second end of the flying capacitor is detected, and the voltage difference between the voltage at the second end of the flying capacitor and the input voltage is detected, and when the absolute value of the voltage difference is within a preset range, the fourth switch is controlled to be turned on.

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