Resonant Switched Capacitor Converter

Abstract

The present invention discloses a resonant switched capacitor converter, comprising: a first resonant circuit; a second resonant circuit; at least one non-resonant capacitor; and a connection control circuit; wherein, during a first stage, the first terminal of the first resonant circuit is connected to a reference terminal through a path without a capacitor, and the first terminal of the second resonant circuit is connected to the output terminal; during a second stage, the first terminal of the first resonant circuit is connected to the output terminal, and the first terminal of the second resonant circuit is connected to the reference terminal through a path without a capacitor. The resonant switched capacitor converter of the present invention does not require the use of any transformer; and has a novel architecture to achieve optimal performance.

Description

Technical Field

[0001] The present invention relates to the field of electrical technology, and in particular to a resonant switched capacitor converter. Background Art

[0002] In order to convert a first direct current (DC) voltage used in a global power bus to a second direct current voltage used in a local system, a DC-DC power converter is required. For example, in data center applications, energy usage may continue to grow (e.g., more than 6% annually), which may be driven by the exponential growth of cloud and big data, so saving a small amount of energy is also considerable in quantity.

[0003] In another example, a car power system requires a DC-DC power converter to convert 48 volts (Volt, V) to 12V for battery powering lighting, seats, windows, engine accessories, and infotainment systems. In yet another example, network and telecommunications infrastructure equipment may need to convert power from 48V to an intermediate bus voltage of 12V.

[0004] In the related art, the above-mentioned power converter can be implemented using a transformer-based architecture. However, the transformer takes up a large area or a large volume in the device. Therefore, a novel power converter is needed to improve the overall performance such as power density, power efficiency and output power without introducing any side effects or in a manner that is less likely to introduce side effects. Summary of the invention

[0005] In view of this, the present invention provides a resonant switched capacitor converter to improve the overall performance of the converter.

[0006] According to a first aspect of the present invention, a resonant switched capacitor converter is disclosed, configured to convert an input voltage at an input terminal of the resonant switched capacitor converter into an output voltage at an output terminal of the resonant switched capacitor converter, wherein the resonant switched capacitor converter comprises:

[0007] The first resonant circuit;

[0008] A second resonant circuit;

[0009] at least one non-resonant capacitor; and

[0010] a connection control circuit coupled to the input terminal, the output terminal, the first resonant tank, the second resonant tank and the at least one non-resonant capacitor, configured to control the connection of the first resonant tank, the second resonant tank, the second resonant tank and the at least one non-resonant capacitor;

[0011] During the first stage, the first terminal of the first resonant circuit is connected to the reference terminal through a path without a capacitor, and the first terminal of the second resonant circuit is connected to the output terminal; during the second stage, the first terminal of the first resonant circuit is connected to the output terminal, and the first terminal of the second resonant circuit is connected to the reference terminal through a path without a capacitor.

[0012] According to a second aspect of the present invention, a resonant switched capacitor converter is disclosed, configured to convert an input voltage at an input terminal of the resonant switched capacitor converter into an output voltage at an output terminal of the resonant switched capacitor converter, wherein the resonant switched capacitor converter comprises:

[0013] The first resonant circuit;

[0014] A second resonant circuit;

[0015] at least one non-resonant capacitor; and

[0016] a connection control circuit coupled to the input terminal, the output terminal, the first resonant tank, the second resonant tank and the at least one non-resonant capacitor, configured to control the connection of the first resonant tank, the second resonant tank, the second resonant tank and the at least one non-resonant capacitor;

[0017] The connection control circuit uses a first group of switches in the connection control circuit to control whether the first terminal of the first resonant circuit is coupled to the reference terminal or the output terminal, and uses a second group of switches in the connection control circuit to control whether the first terminal of the second resonant circuit is coupled to the reference terminal or the output terminal, wherein the first group of switches is different from the second group of switches.

[0018] According to a third aspect of the present invention, a resonant switched capacitor converter is disclosed, configured to convert an input voltage at an input terminal of the resonant switched capacitor converter into an output voltage at an output terminal of the resonant switched capacitor converter, wherein the resonant switched capacitor converter comprises:

[0019] The first resonant circuit;

[0020] A second resonant circuit;

[0021] at least one non-resonant capacitor; and

[0022] a connection control circuit coupled to the input terminal, the output terminal, the first resonant tank, the second resonant tank and the at least one non-resonant capacitor, configured to control the connection of the first resonant tank, the second resonant tank, the second resonant tank and the at least one non-resonant capacitor;

[0023] During the first stage, the second terminal of the first resonant tank is coupled to the output terminal, and the second terminal of the second resonant tank is coupled to the first terminal of the non-resonant capacitor; during the second stage, the second terminal of the first resonant tank is coupled to the second terminal of the non-resonant capacitor, and the second terminal of the second resonant tank is coupled to the output terminal.

[0024] The resonant switched capacitor converter of the present invention has a first terminal of the first resonant circuit connected to a reference terminal through a path without a capacitor during the first stage, and a first terminal of the second resonant circuit connected to the output terminal; and a first terminal of the first resonant circuit connected to the output terminal during the second stage, and a first terminal of the second resonant circuit connected to the reference terminal through a path without a capacitor. The resonant switched capacitor converter of the present invention does not require any transformer and has a novel architecture to achieve optimal performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 is a diagram showing a resonant switched capacitor converter according to an embodiment of the present invention.

[0026] Figure 2 is a diagram showing an embodiment of the present invention Figure 1 The circuit diagram of the resonant switched capacitor converter is shown.

[0027] Figure 3 is a diagram showing a first stage according to an embodiment of the present invention. Figure 2 A diagram of a first configuration of a resonant switched capacitor converter is shown.

[0028] Figure 4 is a diagram showing the process during the second phase according to an embodiment of the present invention. Figure 2 A second configuration of a resonant switched capacitor converter is shown in FIG.

[0029] Figure 5 According to an embodiment of the present invention, Figure 2 Detailed implementation of a resonant switched capacitor converter is shown.

[0030] Figure 6 is a diagram illustrating some non-overlapping edges of some control signals according to an embodiment of the present invention.

[0031] Figure 7 is a diagram showing an embodiment of the present invention Figure 5 Graph of relevant signals for a resonant switched capacitor converter shown in .

[0032] Figure 8 is a diagram illustrating associated signals for different architectures according to an embodiment of the present invention. DETAILED DESCRIPTION

[0033] Certain terms are used throughout the following description and claims to refer to specific components. As will be appreciated by those skilled in the art, electronic device manufacturers may refer to components by different names. This document is not intended to distinguish between components that have different names but the same function. In the following description and claims, the terms "include" and "comprise" are used in an open-ended manner and should therefore be interpreted to mean "including but not limited to...". Similarly, the term "coupled" is intended to mean an indirect or direct electrical connection. Thus, if one device is coupled to another device, the connection may be through a direct electrical connection, or through an indirect electrical connection via other devices and connectors.

[0034] Figure 1 1 is a diagram showing a resonant switched capacitor converter 10 according to an embodiment of the present invention. In this embodiment, the resonant switched capacitor converter 10 is configured to convert an input voltage VIN at an input terminal IN of the resonant switched capacitor converter 10 into an output voltage VOUT at an output terminal OUT of the resonant switched capacitor converter 10. Figure 1 As shown, the resonant switched capacitor converter 10 may include a first resonant tank such as a resonant tank 121, a second resonant tank such as a resonant tank 122, at least one non-resonant capacitor such as a non-resonant capacitor 140, and a connection control circuit 160, wherein the connection control circuit 160 is coupled to an input terminal IN, an output terminal OUT, the resonant tank 121, the resonant tank 122, and the non-resonant capacitor 140, and is configured to control the connection of the resonant tank 121, the resonant tank 122, and the non-resonant capacitor 140.

[0035] For example, the connection control circuit 160 may include a connection control subcircuit 161, but the present invention is not limited thereto. The connection control subcircuit 161 may be coupled to the output terminal OUT, the first terminal of the resonant tank 121, and the first terminal of the resonant tank 122. The connection control circuit 160 may use a first set of switches in the connection control circuit 160 (e.g., the connection control subcircuit 161 therein) to control whether the first terminal of the resonant tank 121 is coupled to the reference terminal or to the output terminal OUT via a path, and may use a second set of switches in the connection control circuit 160 (e.g., the connection control subcircuit 161 therein) to control whether the first terminal of the resonant tank 122 is coupled to the reference terminal or to the output terminal OUT via a path. The first set of switches is different from the second set of switches. The first set of switches includes switches that are not in the second set of switches. Therefore, there is no commonality between the path coupling the first terminal of the first resonant circuit to the reference terminal and the path coupling the first terminal of the second resonant circuit to the reference terminal, and / or there is no common switch between the path coupling the first terminal of the first resonant circuit to the output terminal OUT and the path coupling the first terminal of the second resonant circuit to the output terminal OUT. In one embodiment, during the first phase, the first terminal of the resonant tank 121 is coupled to the reference terminal via a path without any other components (e.g., capacitors, resistors, or any other passive / active devices) other than the switch (one or more), and the first terminal of the resonant tank 122 is coupled to the output terminal OUT; during the second phase, the first terminal of the resonant tank 121 is coupled to the output terminal OUT, and the first terminal of the resonant tank 122 is coupled to the reference terminal via a path without any other components (e.g., capacitors, resistors, or any other passive / active devices) other than the switch (one or more); wherein the reference terminal may be a voltage terminal that provides a fixed voltage such as a ground voltage or a reference voltage.

[0036] In addition, the connection control circuit 160 may further include a connection control subcircuit 162, but the present invention is not limited thereto. The connection control subcircuit 162 may be coupled to the input terminal IN, the output terminal OUT, the second terminal of the resonant tank 121, and the second terminal of the resonant tank 122. During the first stage, the second terminal of the resonant tank 121 is coupled to the output terminal OUT, and the second terminal of the resonant tank 122 is coupled to the first terminal of the non-resonant capacitor 140. In the second stage, the second terminal of the resonant tank 121 is coupled to the second terminal of the non-resonant capacitor 140, and the second terminal of the resonant tank 122 is coupled to the output terminal.

[0037] In one embodiment, the first terminal of the non-resonant capacitor 140 is coupled to the second terminal or the reference terminal of the resonant tank 122, and the second terminal of the non-resonant capacitor 140 is coupled to the input terminal IN. In the first stage, the first terminal of the non-resonant capacitor 140 is coupled to the second terminal of the resonant tank 122, and the second terminal of the non-resonant capacitor 140 is coupled to the input terminal IN; in the second stage, the first terminal of the non-resonant capacitor 140 is coupled to the reference terminal, and the second terminal of the non-resonant capacitor 140 is coupled to the second terminal of the resonant tank 121.

[0038] Figure 2 is a diagram showing an embodiment of the present invention Figure 1 The circuit diagram of the resonant switched capacitor converter 10 is shown in FIG. Figure 2 As shown, the resonant circuit 121 may include a resonant inductor such as an inductor L1 and a resonant capacitor such as a capacitor C1, and more specifically, the resonant circuit 121 may be implemented by the inductor L1 and the capacitor C1 connected in series, wherein the resonant frequency corresponding to the resonant circuit 121 is determined by the inductor L1 and the capacitor C1. In addition, the resonant circuit 122 may include a resonant inductor such as an inductor L2 and a resonant capacitor such as a capacitor C2, and more specifically, the resonant circuit 122 may be implemented by the inductor L2 and the capacitor C2 connected in series, wherein the resonant frequency corresponding to the resonant circuit 122 is determined by the inductor L2 and the capacitor C2. In one embodiment, the inductor L1 may be equivalent to the inductor L2, and the capacitor C1 may be equivalent to the capacitor C2, so the resonant frequency corresponding to the resonant circuit 121 may be equal to the resonant frequency corresponding to the resonant circuit 122. In addition, the non-resonant capacitor 140 (such as Figure 1 As shown) may include a capacitor C3, and more specifically, the capacitance of the capacitor C3 may be much larger than the capacitance of the capacitor C1 or C2, for example, ten times or more larger than the capacitance of the capacitor C1 or C2.

[0039] In one embodiment, the connection control circuit 160 may include a plurality of switches, wherein a portion of the switches are controlled by a first control signal and another portion of the switches are controlled by a second control signal. More specifically, the first control signal and the second control signal are non-overlapping control signals. For example, one of the first control signal and the second control signal may have a duty cycle of fifty percent or less, and the other of the first control signal and the second control signal may have a duty cycle of less than fifty percent, but the present invention is not limited thereto. According to some embodiments, one of the first control signal and the second control signal may have a duty cycle of less than fifty percent, and the other of the first control signal and the second control signal may have a duty cycle of less than fifty percent. Preferably, the two duty cycles may be equal to each other.

[0040] In detail, the connection control subcircuit 161 may include switches SW1, SW2, SW3, and SW4, wherein the switch SW1 is coupled between the first terminal of the resonant tank 121 and a reference terminal (e.g., a ground terminal), the switch SW2 is coupled between the first terminal of the resonant tank 121 and the output terminal OUT, the switch SW3 is coupled between the first terminal of the resonant tank 122 and a reference terminal (e.g., a ground terminal), and the switch SW4 is coupled between the first terminal of the resonant tank 122 and the output terminal OUT. The switches {SW1, SW2} may be examples of a first group of switches within the connection control subcircuit 161, and the switches {SW3, SW4} may be examples of a second group of switches within the connection control subcircuit 161. The connection control subcircuit 162 may include switches SW5, SW6, SW7, SW8, SW9, and SW10, wherein the switch SW5 is coupled between the second terminal of the resonant tank 121 and the output terminal OUT, the switch SW6 is coupled between the second terminal of the resonant tank 121 and the second terminal of the capacitor C3, the switch SW7 is coupled between the second terminal of the resonant tank 122 and the output terminal OUT, the switch SW8 is coupled between the second terminal of the resonant tank 122 and the first terminal of the capacitor C3, the switch SW9 is coupled between the input terminal IN and the second terminal of the capacitor C3, and the switch SW10 is coupled between the first terminal of the capacitor C3 and the reference terminal. More specifically, the switches SW1, SW4, SW5, SW8, and SW9 are controlled by a first control signal (e.g., turned on during the first phase and turned off during the second phase), and the switches SW2, SW3, SW6, SW7, and SW10 are controlled by a second control signal (e.g., turned off during the first phase and turned on during the second phase). It should be noted that the implementation of the connection control circuit 160 (e.g., the connection control subcircuits 161 and 162 therein) is for illustrative purposes only and is not intended to limit the present invention. Any implementation capable of controlling the connection of the resonant tank 121, the resonant tank 122, and the non-resonant capacitor 140 in the above manner should fall within the scope of the present invention.

[0041] Figure 3 is a diagram showing a first stage according to an embodiment of the present invention. Figure 2 FIG. 1 is a diagram of a first configuration of the resonant switched capacitor converter 10 shown in FIG. When switches SW1, SW4, SW5, SW8, and SW9 are turned on and switches SW2, SW3, SW6, SW7, and SW10 are turned off during the first phase, the resonant switched capacitor converter 10 may form a first configuration, such as by Figure 3 Indicated by the bold line. Figure 4 is a diagram showing the process during the second phase according to an embodiment of the present invention. Figure 2FIG. 1 is a diagram of a second configuration of the resonant switched capacitor converter 10 shown in FIG. When switches SW1, SW4, SW5, SW8, and SW9 are turned off and switches SW2, SW3, SW6, SW7, and SW10 are turned on during the second phase, the resonant switched capacitor converter 10 may form a second configuration, such as by Figure 4 Indicated by the bold line.

[0042] Figure 5 According to an embodiment of the present invention, Figure 2 The detailed implementation of the resonant switched capacitor converter 10 is shown in FIG. Figure 5 As shown, the output terminal OUT is also coupled to the output capacitor COUT, and the other end of the output capacitor COUT is coupled to a reference terminal (e.g., a ground terminal). Each of the switches SW1, SW2, SW3, SW4, SW5, SW6, SW7, SW8, SW9, and SW10 can be implemented by, for example, a transistor, such as an N-type Metal-Oxide-Semiconductor Field-Effect Transistor (MOSFET), wherein the gate electrode of each transistor receives a corresponding control signal (e.g., a first control signal (e.g., control signal P1) or a second control signal (e.g., control signal P2)). This implementation of a single switch is for illustrative purposes only and is not intended to limit the present invention. Those skilled in the art should refer to Figure 5 The detailed operation of the transistor used as a switch in this embodiment is understood through the structure shown, and therefore, the detailed operation is omitted for the sake of brevity.

[0043] Figure 6 is a diagram showing some non-overlapping edges of control signals P1 and P2 according to an embodiment of the present invention. Figure 6 As shown, the control signal P2 can change from a low voltage level to a high voltage level at a time point after the control signal P1 changes from a high voltage level to a low voltage level. And the control signal P1 can change from a low voltage level to a high voltage level at a time point after the control signal P2 changes from a high voltage level to a low voltage level. The non-overlapping signal generator can be configured to generate control signals P1 and P2. Those skilled in the art should understand the detailed implementation of the non-overlapping signal generator by referring to the above embodiments, and the relevant description is omitted for the sake of brevity. For example, the control signal P1 can be used to switch the switch of the connection control subcircuit 161, or to switch the switch of the connection control subcircuit 162. Of course, if the control signal P1 can be used to switch the switch of the connection control subcircuit 161, then the control signal P2 can be used to switch the switch of the connection control subcircuit 162, and vice versa, which can be freely set.

[0044] For optimal performance, the frequency of each of the first control signal such as control signal P1 and the second control signal such as control signal P2 (referred to as an operating frequency) may be equal to the frequency corresponding to the resonant tank 121 / 122. For example, after determining the inductance of the inductor L1 (or L2) and the capacitance of the capacitor C1 (or C2), the operating frequency may be set according to the inductance and the capacitance.

[0045] For example, based on Figure 2 In the architecture shown, the voltage (e.g., average voltage) on capacitor C3 may be 0.5 times the input voltage VIN, and the voltage (e.g., average voltage) on each of capacitors C1 and C2 may be 0.25 times the input voltage VIN. For example, when the input voltage VIN is 48 volts (V), the average voltage across capacitor C3 may be 24V, the average voltage across each of capacitors C1 and C2 may be 12V, and the average value of the output voltage VOUT (e.g., the output voltage VOUT across output capacitor COUT) may be 12V. In other words, the input voltage VIN is 4 times the output voltage VOUT, the average voltage across capacitor C3 is 2 times the average voltage across each of capacitors C1 and C2, and the average voltage across each of capacitors C1 and C2 is equal to the output voltage VOUT. By this method of the present embodiment, the converter can have the function of step-down conversion, and the conversion is performed through two different sets of switches in the two stages of conversion, avoiding large current flowing through the switch, thereby reducing power loss and improving conversion efficiency. Of course, the above input voltage VIN is 48V, the average value of the output voltage VOUT can be 12V, and the conversion multiple of the converter is an example for easy understanding. In this embodiment, the input voltage, the output voltage and the conversion multiple of the converter can be freely set as needed, for example, the conversion multiple can be 0.2, 0.3, 0.4, etc. For example, changing the conversion multiple can be achieved by, for example, changing the capacitance value of capacitors C1, C2 and / or C3, or increasing the number of capacitors at the corresponding positions of capacitors C1, C2 and / or C3, etc.

[0046] Figure 7 is a diagram showing an embodiment of the present invention Figure 5 , where it is assumed that C3=COUT=100 microfarads (uF), C1=C2=10uF, and L1=L2=10 nanohenry (nH). Under the condition that the operating frequency is equal to the resonant frequency corresponding to the resonant tank 121 / 122 (e.g., 600kHz), each control signal P1 and P2 (for simplicity, in Figure 7The control signal P2 is not shown in the figure, and near the time point of the resonant inductor (e.g., inductor L1 and L2) with zero current (e.g., 0 ampere (A)), there is no overlap between the various high voltage levels of the control signals P1 and P2. For example, when the resonant switched capacitor converter 10 is powered on and the operating frequency is equal to the resonant frequency, the time point of the resonant inductor (e.g., inductor L1 and L2) with zero current can gradually follow the control signals P1 and P2, and finally become synchronized with the transition of the control signals P1 and P2. In addition, as Figure 7 As shown in FIG. 1 , the average voltage across capacitors C1 and C2 is 12V (which is equal to the output voltage VOUT). Figure 7 As shown, the control signal P1 is set to switch the falling edge at the position where the inductors L1 and L2 have zero current. This can avoid the large switching loss caused by switching when the inductors L1 and L2 have a large current. Therefore, the solution of the embodiment of the present invention can reduce the switching loss and improve the conversion efficiency. In this embodiment, the control signal P1 can control switches SW1, SW4, SW5, SW8 and SW9, or control switches SW2, SW3, SW6, SW7 and SW10. For example, the control signal P1 controls switches SW1, SW4, SW5, SW8 and SW9, and the control signal P2 controls switches SW2, SW3, SW6, SW7 and SW10; when switches SW1, SW4, SW5, SW8 and SW9 are disconnected, switches SW2, SW3, SW6, SW7 and SW10 are closed; and vice versa. In addition, the control signal P1 can also be set to switch the rising edge at the position where the inductors L1 and L2 have zero current. All of the above can be freely set according to actual needs.

[0047] In some variations, the connection control circuit 160 may be modified, for example, the connection control circuit 160 may be implemented by eight switches instead of ten switches. Figure 2 , the first terminal of the resonant tank 121 (the terminal to which the inductor L1 is connected to the outside) and the first terminal of the resonant tank 122 (the terminal to which the inductor L2 is connected to the outside) can be coupled to the same node, wherein the node can be coupled to the output terminal OUT during the first phase and coupled to the reference terminal during the second phase, for example, sharing the same set of switches for controlling the connection. Figure 2In the ten-switch architecture shown, the first end of the resonant circuit 121 and the first terminal of the resonant circuit 122 can be controlled separately by different switch groups. For example, switches SW1 and SW2 are configured to control the connection of the first terminal of the resonant circuit 121, and switches SW3 and SW4 are configured to control the connection of the first terminal of the resonant circuit 122. Of course, if an eight-switch implementation is adopted, the current through some switches (for example, switches that share the same group for controlling the connection) may become larger due to the parallel connection between the resonant circuit 121 and the resonant circuit 122 during the conversion period; and due to the power loss P of the switch = I 2 R (where I is the current through the switch and R is the resistance of the switch); therefore, the power loss of the switch will be greatly increased, thereby affecting the conversion efficiency of the converter, and may cause a large error between the output voltage VOUT and the expected value. In this embodiment, the above ten switch implementations can be adopted. During the conversion period (for example Figure 3 During the conversion period shown in the figure), the resonant circuit 121 and the resonant circuit 122 are not connected in parallel (for example, they are connected in series), so that the current passing through the switch (for example, switch SW1, SW4, SW5, SW8 or SW9) is relatively small, so that the loss of the switch is greatly reduced, and the conversion efficiency is improved. And during the conversion period (for example Figure 4 During the conversion period shown in the figure), the current flowing through each switch (such as switch SW6, SW7, etc.) on the resonant circuit 121 and the resonant circuit 122 is also small (the average voltage on the capacitors C1 and C2 is small), so the switching loss is also small at this time, so the conversion efficiency of the converter is further improved, and the performance is significantly improved.

[0048] Figure 8 is a diagram showing related signals of an architecture with eight switches and an architecture with ten switches according to an embodiment of the present invention, wherein: Figure 8 The left half of the diagram shows the signals for an architecture with eight switches, and Figure 8 The right half of shows the signals of the architecture with ten switches. Compared with the architecture with eight switches, since the architecture with ten switches uses more than two switches, the overall effective on-resistance of the architecture with ten switches can be reduced, so the overall efficiency can be improved. According to the above analysis, according to the example given in this embodiment, Figure 8As shown, the architecture with eight switches obtains an average voltage of 11.83V with a ripple of 61mV (compared to the expected VOUT of 12V, the voltage drop is 12-11.83=0.17V, which means that a 170millivolt (mV) voltage drop is introduced, and there is a difference of 170mV from the expected voltage value), and the architecture with ten switches obtains an average voltage of 11.89V with a ripple of 61mV (compared to the expected VOUT of 12V, the voltage drop is 12-11.89=0.11V, which means that a 110mV voltage difference is introduced, and there is a difference of 110mV from the expected voltage value). Therefore, the architecture with ten switches has a smaller voltage drop (smaller difference from the expected VOUT), is more in line with the design requirements and the expected output voltage value, and has a higher conversion efficiency.

[0049] In the prior art, the transformer-based converter occupies a large area, making it difficult to adapt to the increasingly miniaturized design requirements. In addition, in some switched capacitor converters in the prior art, the power loss on the switch is large due to the large current passing through the switch, which affects the conversion efficiency. The switched capacitor converter provided in the embodiment of the present invention does not use a transformer, so the area is small and adapts to the miniaturized design requirements; and during the conversion, two different sets of switches are used to form a conversion path (and there is no sharing between the two sets of switches), thereby reducing the current passing through the switch, which significantly reduces the power loss on the switch, thereby improving the conversion efficiency of the converter. Therefore, the embodiment of the present invention improves the overall performance such as power density, power efficiency and output power without introducing any side effects or in a way that is unlikely to introduce side effects. In summary, the embodiment of the present invention provides a resonant switched capacitor converter without using any transformer. In addition, the embodiment of the present invention provides a novel architecture of a resonant switched capacitor converter (for example, an architecture with ten switches) to achieve optimal performance (for example, dropout voltage and / or power efficiency). Therefore, the present invention can improve the overall performance without introducing any side effects or in a way that is unlikely to introduce side effects.

[0050] Those skilled in the art will readily observe that many modifications and variations of the apparatus and method can be made while maintaining the teachings of the present invention.Accordingly, the above disclosure should be interpreted as being limited only by the metes and bounds of the appended claims.

Claims

1. A resonant switched capacitor converter, configured to convert an input voltage at an input terminal of the resonant switched capacitor converter into an output voltage at an output terminal of the resonant switched capacitor converter, characterized in that: The resonant switched capacitor converter comprises: The first resonant circuit; A second resonant circuit; at least one non-resonant capacitor; and a connection control circuit coupled to the input terminal, the output terminal, the first resonant tank, the second resonant tank and the at least one non-resonant capacitor, configured to control the connection of the first resonant tank, the second resonant tank, the second resonant tank and the at least one non-resonant capacitor; During the first stage, the first terminal of the first resonant circuit is connected to the reference terminal through a path without a capacitor, and the first terminal of the second resonant circuit is connected to the output terminal; during the second stage, the first terminal of the first resonant circuit is connected to the output terminal, and the first terminal of the second resonant circuit is connected to the reference terminal through a path without a capacitor, wherein the reference terminal provides a ground voltage or a reference voltage.

2. The resonant switched capacitor converter according to claim 1, wherein: During the first phase, a second terminal of the first resonant tank is coupled to the output terminal, and a second terminal of the second resonant tank is coupled to a first terminal of the non-resonant capacitor; In the second stage, the second terminal of the first resonant tank is coupled to the second terminal of the non-resonant capacitor, and the second terminal of the second resonant tank is coupled to the output terminal.

3. The resonant switched capacitor converter according to claim 1, wherein: During the first phase, a first terminal of the non-resonant capacitor is coupled to a second terminal of the second resonant tank, and a second terminal of the non-resonant capacitor is coupled to the input terminal; During the second phase, a first terminal of the non-resonant capacitor is coupled to the reference terminal and a second terminal of the non-resonant capacitor is coupled to a second terminal of the first resonant tank.

4. The resonant switched capacitor converter according to claim 1, wherein: The voltage on the non-resonant capacitor is 0.5 times the input voltage.

5. The resonant switched capacitor converter according to claim 1, wherein: The connection control circuit includes a switch, a part of which is controlled by a first control signal, and another part of which is controlled by a second control signal.

6. The resonant switched capacitor converter according to claim 5, wherein: The first control signal and the second control signal are non-overlapping control signals; one of the first control signal and the second control signal has a duty cycle of fifty percent or less, and the other of the first control signal and the second control signal has a duty cycle less than fifty percent.

7. The resonant switched capacitor converter according to claim 5, wherein: A frequency of each of the first control signal and the second control signal is equal to a resonant frequency corresponding to the first resonant tank and the second resonant tank.

8. The resonant switched capacitor converter according to claim 1, wherein: Each of the first resonant tank and the second resonant tank includes a resonant inductor and a resonant capacitor, and a resonant frequency corresponding to each resonant tank is determined by the resonant inductor and the resonant capacitor.

9. The resonant switched capacitor converter according to claim 8, wherein: The voltage across the resonant capacitor is 0.25 times the input voltage.

10. A resonant switched capacitor converter, configured to convert an input voltage at an input terminal of the resonant switched capacitor converter into an output voltage at an output terminal of the resonant switched capacitor converter, characterized in that: The resonant switched capacitor converter comprises: The first resonant circuit; A second resonant circuit; at least one non-resonant capacitor; and a connection control circuit coupled to the input terminal, the output terminal, the first resonant tank, the second resonant tank and the at least one non-resonant capacitor, configured to control the connection of the first resonant tank, the second resonant tank, the second resonant tank and the at least one non-resonant capacitor; The connection control circuit uses a first group of switches in the connection control circuit to control whether the first terminal of the first resonant tank is coupled to a reference terminal or the output terminal, and uses a second group of switches in the connection control circuit to control whether the first terminal of the second resonant tank is coupled to the reference terminal or the output terminal, wherein the first group of switches is different from the second group of switches, and the reference terminal provides a ground voltage or a reference voltage.

11. A resonant switched capacitor converter, configured to convert an input voltage at an input terminal of the resonant switched capacitor converter into an output voltage at an output terminal of the resonant switched capacitor converter, characterized in that: The resonant switched capacitor converter comprises: The first resonant circuit; A second resonant circuit; at least one non-resonant capacitor; and a connection control circuit coupled to the input terminal, the output terminal, the first resonant tank, the second resonant tank and the at least one non-resonant capacitor, configured to control the connection of the first resonant tank, the second resonant tank, the second resonant tank and the at least one non-resonant capacitor; During the first stage, the second terminal of the first resonant tank is coupled to the output terminal, and the second terminal of the second resonant tank is coupled to the first terminal of the non-resonant capacitor; during the second stage, the second terminal of the first resonant tank is coupled to the second terminal of the non-resonant capacitor, and the second terminal of the second resonant tank is coupled to the output terminal.

12. The resonant switched capacitor converter according to claim 11, wherein: During the first phase, the second terminal of the non-resonant capacitor is coupled to the input terminal; and during the second phase, the first terminal of the non-resonant capacitor is coupled to a reference terminal, wherein the reference terminal provides a ground voltage or a reference voltage.

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