A charge pump

Abstract

The application discloses a charge pump, wherein after the current of an inductor in the charge pump is increased to a target current, the inductor is kept in a state that the difference between the current and the target current is less than or equal to a current threshold value through a freewheeling module, so that the resonant loop formed by the first energy storage module, the second energy storage module and the freewheeling module releases the stored electric energy in the switching elements, and the voltage difference between the switching elements is reduced before the switching elements are switched on, thereby reducing the switching loss and improving the conversion efficiency.

Description

Technical Field

[0001] This application relates to electronic technology, and to, but is not limited to, a charge pump. Background Technology

[0002] Charge pumps, as a basic voltage conversion structure, are widely used in various power management applications. Charge pumps can convert a DC voltage of one value into a DC voltage output of another value, thereby achieving voltage conversion.

[0003] Switching losses are a crucial indicator of charge pump performance, determining its load-carrying capacity and temperature rise. Lower switching losses result in greater load-carrying capacity and lower temperature rise in the voltage converter. One cause of switching losses in charge pumps is the conduction loss of the individual switches in the circuit during operation. This conduction loss is directly proportional to the voltage difference across the switches during switching; a larger voltage difference leads to greater conduction loss. Therefore, reducing conduction losses to improve the voltage conversion efficiency of charge pumps is a pressing issue in this field. Summary of the Invention

[0004] In view of this, the charge pump provided in this application embodiment can reduce the voltage difference across each switching transistor before switching, thereby reducing switching losses and improving conversion efficiency.

[0005] The charge pump provided in this application embodiment includes a control module, a freewheeling module, a first energy storage module, and a second energy storage module. The freewheeling module includes an inductor and multiple switching elements. Both the first and second energy storage modules include a capacitor and multiple switching elements. The freewheeling module is connected to both the first and second energy storage modules. The control module is connected to the freewheeling module, the first energy storage module, and the second energy storage module, respectively.

[0006] The control module is used to control the first and second sets of multiple switching elements in the first and second energy storage modules to periodically turn on or off, and to control the third and fourth sets of multiple switching elements in the freewheeling module to periodically turn on or off.

[0007] The freewheeling module is used, under the control of the control module, to gradually increase the current of the inductor to the target current, and then keep the current of the inductor in a state where the difference between the current and the target current is less than or equal to a current threshold.

[0008] The first energy storage module, the second energy storage module, and the freewheeling module are further configured to form a resonant circuit when all the switching elements in the first and second sets of switching elements are disconnected, releasing the electrical energy stored in the switching elements in the first and second sets of switching elements until the voltage difference across the switching elements in the first and second sets of switching elements is less than or equal to a voltage threshold.

[0009] In the aforementioned charge pump, after the current in the inductor of the charge pump increases to the target current, the freewheeling module maintains the inductor in a state where the difference between the current and the target current is less than or equal to the current threshold. This allows the stored electrical energy in the switching elements to be released through the resonant circuit formed by the first energy storage module, the second energy storage module, and the freewheeling module when multiple switching elements in the first and second energy storage modules are disconnected. This ensures that the voltage difference across the multiple switching elements in the first and second energy storage modules is reduced before the switching is performed, thereby reducing switching losses and improving conversion efficiency. Attached Figure Description

[0010] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with this application and, together with the specification, serve to explain the technical solutions of this application.

[0011] Figure 1 This is a schematic diagram of a charge pump that achieves an input-output ratio of 3:1 in related technologies.

[0012] Figure 2 This is a schematic diagram of the charge pump provided in an embodiment of this application;

[0013] Figure 3 This application provides a schematic diagram of the structure of the first energy storage module and the second energy storage module in an embodiment.

[0014] Figure 4 A schematic diagram of the implementation structure of the charge pump provided in this application embodiment;

[0015] Figure 5A Timing diagram of the third set of switching elements provided in the embodiments of this application within one conduction cycle;

[0016] Figure 5B Timing diagram of another conduction cycle for the third set of switching elements provided in the embodiments of this application;

[0017] Figure 6 A timing diagram of the second on-time of the fourth set of switching elements provided in the embodiments of this application;

[0018] Figure 7Timing diagrams of the reference conduction duration, the first sub-duration, and the second conduction duration provided for embodiments of this application;

[0019] Figure 8 A timing diagram showing the difference between the conduction start position of the second set of switching elements and the conduction end position of the first set of switching elements, as well as the second sub-duration, provided in the embodiments of this application.

[0020] Figure 9 This is a schematic diagram of the structure of the continuous flow module provided in the embodiments of this application;

[0021] Figure 10 A timing diagram of a charge pump within one cycle provided in an embodiment of this application;

[0022] Figure 11 A current flow diagram of a charge pump provided in this application during a period t1 of one cycle;

[0023] Figure 12 A current flow diagram of a charge pump provided in an embodiment of this application during a period t3 of one cycle;

[0024] Figure 13 A current flow diagram of a charge pump provided in an embodiment of this application during a period t4 of one cycle;

[0025] Figure 14 The current flow diagram of the charge pump provided in this application during a period t5 of one cycle. Detailed Implementation

[0026] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the specific technical solutions of this application will be further described in detail below with reference to the accompanying drawings of the embodiments of this application. The following embodiments are used to illustrate this application, but are not intended to limit the scope of this application.

[0027] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing embodiments of this application only and is not intended to limit this application.

[0028] In the following description, references are made to “some embodiments,” which describe a subset of all possible embodiments. However, it is understood that “some embodiments” may be the same subset or different subsets of all possible embodiments and may be combined with each other without conflict.

[0029] It should be noted that the terms "first, second, third" used in the embodiments of this application are used to distinguish similar or different objects and do not represent a specific order of objects. It can be understood that "first, second, third" can be interchanged in a specific order or sequence where permitted, so that the embodiments of this application described herein can be implemented in an order other than that illustrated or described herein.

[0030] Figure 1 This is a schematic diagram of a charge pump that achieves an input-output ratio of 3:1 in related technologies. The charge pump includes a first energy storage module and a second energy storage module, which are connected in parallel between the input terminal VIN and the output terminal VOUT. The first energy storage module includes a first switch Q1A, a second switch Q2A, a third switch Q3A, a fourth switch Q4A, a fifth switch Q5A, a sixth switch Q6A, and a seventh switch Q7A, as well as a first capacitor C1A and a second capacitor C2A. The gates of the first switch Q1A, second switch Q2A, third switch Q3A, fourth switch Q4A, fifth switch Q5A, sixth switch Q6A, and seventh switch Q7A are all connected to the controller. The drain of the first switch Q1A is connected to the input terminal VIN. The source of the first switch Q1A is connected to the drain of the second switch Q2A and one end of the first capacitor C1A, respectively. The source of the second switch Q2A is connected to the output terminal VOUT, respectively. The output terminal VOUT is connected to the source of the fifth switch Q5A. The source of the fifth switch Q5A is connected to the output terminal VOUT. The other end of the first capacitor C1A is connected to the drain of the third switch Q3A and the source of the fourth switch Q4A. The source of the third switch Q3A is connected to ground. The drain of the fourth switch Q4A is connected to the drain of the fifth switch Q5A and one end of the second capacitor C2A. The other end of the second capacitor C2A is connected to the drain of the sixth switch Q6A and the source of the seventh switch Q7A. The source of the sixth switch Q6A is connected to ground. The drain of the seventh switch Q7A is connected to the output terminal VOUT, the second energy storage module, and the source of the fifth switch Q5A.

[0031] The second energy storage module includes an eighth switch Q1B, a ninth switch Q2B, a tenth switch Q3B, an eleventh switch Q4B, a twelfth switch Q5B, a thirteenth switch Q6B, and a fourteenth switch Q7B, as well as a third capacitor C1B and a fourth capacitor C2B. The gates of the eighth switch Q1B, the ninth switch Q2B, the tenth switch Q3B, the eleventh switch Q4B, the twelfth switch Q5B, the thirteenth switch Q6B, and the fourteenth switch Q7B are all connected to the controller. The drain of the eighth switch Q1B is connected to the input terminal VIN. The source of the eighth switch Q1B is connected to the drain of the ninth switch Q2B and one end of the third capacitor C1B. The source of the ninth switch Q2B is connected to the output terminal. VOUT is connected to the source of the twelfth switch Q5B. The source of the twelfth switch Q5B is connected to the output terminal VOUT. The other end of the third capacitor C1B is connected to the drain of the tenth switch Q3B and the source of the eleventh switch Q4B. The source of the tenth switch Q3B is connected to ground. The drain of the eleventh switch Q4B is connected to the drain of the twelfth switch Q5B and one end of the fourth capacitor C2B. The other end of the fourth capacitor C2B is connected to the drain of the thirteenth switch Q6B and the source of the fourteenth switch Q7B. The source of the thirteenth switch Q6B is connected to ground. The drain of the fourteenth switch Q7B is connected to the output terminal VOUT, the second energy storage module, and the source of the twelfth switch Q5B.

[0032] To achieve a 3:1 input-output conversion ratio, the charge pump comprises two operating time periods (t1 to t2) within one cycle. During time period t1, the first, fourth, and seventh switches (Q1A, Q4A, and Q7A) of the first energy storage module are all turned on, while the second, third, fifth, and sixth switches (Q2A, Q3A, Q5A, and Q6A) are all turned off. The first capacitor (C1A) and the second capacitor (C2A) are connected in series between the input voltage VIN and the output voltage VOUT. In the second energy storage module, the eighth, eleventh, and fourteenth switches (Q7B) are all turned off, while the ninth, tenth, twelfth, and thirteenth switches (Q2B, Q3B, Q5B, and Q6B) are all turned on. The third capacitor (C1B) and the fourth capacitor (C2B) are connected in parallel between the output voltage VOUT and ground (GND).

[0033] During time period t2, the first switch Q1A, the fourth switch Q4A, and the seventh switch Q7A of the first energy storage module are all off, while the second switch Q2A, the third switch Q3A, the fifth switch Q5A, and the sixth switch Q6A are all on. The first capacitor C1A and the second capacitor C2A are connected in parallel and between the output voltage VOUT and ground GND. The eighth switch Q1B, the eleventh switch Q4B, and the fourteenth switch Q7B of the second energy storage module are on, while the ninth switch Q2B, the tenth switch Q3B, the twelfth switch Q5B, and the thirteenth switch Q6B are off. The third capacitor CF1B and the fourth capacitor CF2B are connected in series and between the input voltage VIN and the output voltage VOUT. The operation alternates between t1 and t2, achieving an output voltage VOUT = VIN / 3 and an output current IOUT = 3 * IIN.

[0034] However, at the moment the aforementioned switching transistor is turned on, the voltage difference between its drain and source is not 0V, or is not close to 0V, for example... Figure 1 Taking the first switching transistor Q1A as an example, if the input voltage is 30V, when only the second switching transistor Q2A is turned on, the voltage at node C1PA is 10V, meaning the voltage difference between the drain and source of the first switching transistor Q1A is 20V. After the second switching transistor Q2A is turned off, a dead time occurs where no switching transistor is turned on. During this dead time, due to the parasitic capacitance of the switching transistors, the voltage difference between the drain and source of the first switching transistor Q1A remains at 20V. After the dead time ends, the first switching transistor Q1A turns on. Since the turn-on of the first switching transistor Q1A is not instantaneous, the voltage difference between its drain and source cannot immediately drop to 0V. This means that while the voltage difference is not zero, current flows through the first switching transistor Q1A, leading to conduction losses during the turn-on process and reducing voltage conversion efficiency.

[0035] To address the aforementioned problems, this application provides a charge pump that can be applied to electronic devices to ensure voltage conversion efficiency during the voltage conversion of input electrical signals according to a preset conversion ratio. This electronic device can be of various types with information processing capabilities. For example, it can include personal computers, laptops, PDAs, or servers; it can also be a mobile terminal, such as a mobile phone, in-vehicle computer, tablet computer, or projector.

[0036] The technical solutions in the embodiments of this application will now be described with reference to the accompanying drawings.

[0037] Figure 2 This is a schematic diagram of a charge pump provided in this application. Figure 2As shown, the charge pump includes a control module 101, a freewheeling module 104, a first energy storage module 102, and a second energy storage module 103. The freewheeling module 104 includes an inductor and multiple switching elements. The first energy storage module 102 and the second energy storage module 103 each include a capacitor and multiple switching elements. The freewheeling module 104 is connected to both the first energy storage module 102 and the second energy storage module 103. The control module 101 is connected to both the freewheeling module 104, the first energy storage module 102, and the second energy storage module 103.

[0038] The control module 101 is used to control the first set of switching elements and the second set of switching elements of multiple switching elements in the first energy storage module 102 and the second energy storage module 103 to periodically turn on or off, and to control the third set of switching elements and the fourth set of switching elements of multiple switching elements in the freewheeling module 104 to periodically turn on or off.

[0039] The freewheeling module 104 is used to gradually increase the current of the inductor to the target current under the control of the control module 101, and then keep the current of the inductor in a state where the difference between the current and the target current is less than or equal to the current threshold.

[0040] The first energy storage module 102, the second energy storage module 103, and the freewheeling module 104 are also used to form a resonant circuit when the switching elements in the first and second sets of switching elements are both disconnected, and release the electrical energy stored in the switching elements in the first and second sets of switching elements until the voltage difference across the switching elements in the first and second sets of switching elements is less than or equal to the voltage threshold.

[0041] It should be understood that the specific structures of the first energy storage module 102 and the second energy storage module 103 described above adopt structures in related technologies, such as... Figure 3 As shown, the first energy storage module 102 includes a first switching element and N basic units, and the second energy storage module 103 includes a second switching element and N basic units, where N is greater than or equal to 1. The freewheeling module 104 is connected to one of the basic units of the first energy storage module 102 and one of the basic units of the second energy storage module 103. The first end of the first switching element is connected to the first connection terminal of the charge pump, which can be either an input or an output terminal. The second end of the first switching element is sequentially connected to the second connection terminal of the charge pump through N basic units, which can also be either an output or an input terminal. The N basic units are connected in series. Similarly, the first end of the second switching element is connected to the first connection terminal of the charge pump, which can be either an input or an output terminal. The second end of the second switching element is sequentially connected to the second connection terminal of the charge pump through N basic units, which can also be either an output or an input terminal. The N basic units are connected in series.

[0042] Furthermore, each basic unit includes a capacitor, a third switching element, a fourth switching element, and a fifth switching element. The first end of the capacitor is connected to the first end of the third switching element, and the first end of the capacitor is the first connection terminal of the basic unit. The second end of the third switching element is the second connection terminal of the first basic unit. The second end of the capacitor is connected to the first ends of the fourth and fifth switching elements. The second end of the fourth switching element is grounded. The second end of the fifth switching element is the third connection terminal of the first basic unit. The first switching element is connected to the first connection terminal of the basic unit. The second connection terminal of the charge pump is connected to the second connection terminal and the third connection terminal of the basic unit, respectively. If the number of basic units is greater than 1, any two interconnected basic units are connected through a target connection method. This target connection method is that the first connection terminal of one basic unit is connected to the third connection terminal of the next basic unit, and the second connection terminal of one basic unit is connected to the second connection terminal of the next basic unit.

[0043] Furthermore, to achieve the voltage regulation result of the charge pump described above, it is necessary to control the aforementioned multiple switching elements separately. For example, in the related technology, during the voltage regulation process with an input-output ratio of 3:1, it is necessary to control the first switch Q1A, the fourth switch Q4A, and the seventh switch Q7A of the first energy storage module 102 to be turned on, and the second switch Q2A, the third switch Q3A, the fifth switch Q5A, and the sixth switch Q6A to be turned off during the time period t1. It is also necessary to control the eighth switch Q1B, the eleventh switch Q4B, and the fourteenth switch Q7B of the second energy storage module 103 to be turned off, and the ninth switch Q2B, the tenth switch Q3B, the twelfth switch Q5B, and the thirteenth switch Q6B to be turned on during the time period t2. During the time period t2, it is necessary to control the first switch Q1A, the fourth switch Q4A, and the seventh switch Q7A of the first energy storage module 102 to be turned on. When all switches Q7A are turned off, the second switch Q2A, the third switch Q3A, the fifth switch Q5A, and the sixth switch Q6A are all turned on, controlling the eighth switch Q1B, the eleventh switch Q4B, and the fourteenth switch Q7B of the second energy storage module 103 to turn on, and the ninth switch Q2B, the tenth switch Q3B, the twelfth switch Q5B, and the thirteenth switch Q6B to turn off. Therefore, in this embodiment, the multiple switching elements in the first energy storage module 102 and the second energy storage module 103 are divided into a first set of switching elements and a second set of switching elements to control some of the multiple switching elements to be turned on or off simultaneously. The first set of switching elements consists of the first switching element and the fifth switching element in each basic unit, and the second set of switching elements consists of the second switching element and the third and fourth switching elements in each basic unit.

[0044] For example, such as Figure 4As shown, taking N=2 and the first switching element connected to the input terminal as an example, the first energy storage module 102 includes a first switching transistor Q1A and two basic units. The first basic unit includes a first capacitor C1A, a second switching transistor Q2A, a third switching transistor Q3A, and a fourth switching transistor Q4A. The second basic unit includes a second capacitor C2A, a fifth switching transistor Q5A, a sixth switching transistor Q6A, and a seventh switching transistor Q7A. The gates of the first switching transistors Q1A, Q2A, Q3A, Q4A, Q5A, Q6A, and Q7A are all connected to the controller. The drain of the first switching transistor Q1A is connected to the input terminal VIN. The source of the first switching transistor Q1A is connected to the drain of the second switching transistor Q2A and the first capacitor C1A, respectively. One end of A is connected, the source of the second switch Q2A is connected to the output terminal VOUT and the source of the fifth switch Q5A respectively, the source of the fifth switch Q5A is connected to the output terminal VOUT, the other end of the first capacitor C1A is connected to the drain of the third switch Q3A and the source of the fourth switch Q4A respectively, the source of the third switch Q3A is connected to ground, the drain of the fourth switch Q4A is connected to the drain of the fifth switch Q5A and one end of the second capacitor C2A respectively, the other end of the second capacitor C2A is connected to the drain of the sixth switch Q6A and the source of the seventh switch Q7A respectively, the source of the sixth switch Q6A is connected to ground, and the drain of the seventh switch Q7A is connected to the output terminal VOUT, the second energy storage module 103 and the source of the fifth switch Q5A respectively.

[0045] The second energy storage module 103 includes an eighth switch Q1B and two basic units. The first basic unit includes a third capacitor C1B, a ninth switch Q2B, a tenth switch Q3B, and an eleventh switch Q4B. The second basic unit includes a fourth capacitor C2B, a twelfth switch Q5B, a thirteenth switch Q6B, and a fourteenth switch Q7B. The gates of the eighth switch Q1B, ninth switch Q2B, tenth switch Q3B, eleventh switch Q4B, twelfth switch Q5B, thirteenth switch Q6B, and fourteenth switch Q7B are all connected to the controller. The drain of the eighth switch Q1B is connected to the input terminal VIN. The source of the eighth switch Q1B is connected to the drain of the ninth switch Q2B and one end of the third capacitor C1B, respectively. The ninth switch... The source of Q2B is connected to the output terminal VOUT and the source of the twelfth switch Q5B, respectively. The source of the twelfth switch Q5B is connected to the output terminal VOUT. The other end of the third capacitor C1B is connected to the drain of the tenth switch Q3B and the source of the eleventh switch Q4B, respectively. The source of the tenth switch Q3B is connected to ground. The drain of the eleventh switch Q4B is connected to the drain of the twelfth switch Q5B and one end of the fourth capacitor C2B, respectively. The other end of the fourth capacitor C2B is connected to the drain of the thirteenth switch Q6B and the source of the fourteenth switch Q7B, respectively. The source of the thirteenth switch Q6B is connected to ground. The drain of the fourteenth switch Q7B is connected to the output terminal VOUT, the second energy storage module 103, and the source of the twelfth switch Q5B, respectively.

[0046] The freewheeling module 104 includes a fifteenth switch Q8A, a sixteenth switch Q8B, an inductor L, a seventeenth switch Q9A, and an eighteenth switch Q9B. The drain of the fifteenth switch Q8A is connected to one end of the first capacitor C1A, the drain of the third switch Q3A, and the source of the fourth switch Q4A. The source of the fifteenth switch Q8A is connected to one end of the inductor L and the drain of the seventeenth switch Q9A. The other end of the inductor L is connected to the source of the sixteenth switch Q8B and the drain of the eighteenth switch Q9B. The sources of the seventeenth switch Q9A and the eighteenth switch Q9B are both connected to ground. The drain of the sixteenth switch Q8B is connected to one end of the third capacitor C1B, the drain of the tenth switch Q3B, and the source of the eleventh switch Q4B.

[0047] The first set of switching elements includes the first switch Q1A, the fourth switch Q4A, the seventh switch Q7A, the ninth switch Q2B, the tenth switch Q3B, the twelfth switch Q5B, and the thirteenth switch Q6B; the second set of switching elements includes the second switch Q2A, the third switch Q3A, the fifth switch Q5A, the sixth switch Q6A, the eighth switch Q1B, the eleventh switch Q4B, and the fourteenth switch Q7B; the third set of switching elements includes the fifteenth switch Q8A and the sixteenth switch Q8B; and the fourth set of switching elements includes the seventeenth switch Q9A and the eighteenth switch Q9B.

[0048] Optionally, the control module 101 can be a single unit or two or more units. When the control module 101 is a single unit, it can send different control commands to the multiple switching elements at different times, thereby controlling the first set of switching elements and the second set of switching elements to periodically turn on or off. That is, the first set of switching elements corresponds to the first control timing sequence, and the second set of switching elements corresponds to the second control timing sequence. When there are two or more control modules 101, at least two control modules 101 control multiple switching elements respectively. For example, the first control module 101 controls the first set of switching elements to periodically turn on or off, and the second control module 101 controls the second set of switching elements to periodically turn on or off. The first control module 101 can control the first set of switching elements according to the first control timing sequence, and the second control module 101 can control the second set of switching elements according to the second control timing sequence. The specific settings can be made by those skilled in the art according to the actual situation, and this application does not impose any restrictions.

[0049] Optionally, the method for determining whether the inductor current has increased to the target current can be to determine whether the duration of the inductor current increase has reached a preset duration. Since the freewheeling module 104 is directly connected to the first energy storage module 102 and the second energy storage module 103, the moment when the inductor current in the freewheeling module 104 begins to increase is controllable. Those skilled in the art can calculate the threshold duration required for the inductor current to increase to the target current according to the specific device parameters in the charge pump, and thus start timing from the moment the inductor current begins to increase. When the timing duration reaches the threshold duration, it is determined that the inductor current has increased to the target current. Alternatively, the current at the inductor can be detected by a current detector, and the value collected by the current detector can be used to determine whether the inductor current has increased to the target current.

[0050] It should be noted that the target current mentioned above is the maximum current that minimizes the conduction loss of the switching element during the switching process. The specific calculation method adopts common calculation methods, and the specific current value can be set by those skilled in the art according to the actual situation. This application does not impose any restrictions.

[0051] It should be understood that in order to ensure that the inductor current of the freewheeling module 104 is kept in a state where the difference between the current and the target current is less than or equal to the current threshold, the control module 101 controls the third and fourth sets of switching elements in the freewheeling module 104 to periodically turn on or off. At this time, in order to maintain the inductor current, the connection between the first energy storage module 102 and the freewheeling module 104, as well as the connection between the second energy storage module 103 and the freewheeling module 104, are both in a disconnected state. Then, the inductor current is maintained. In order to achieve the aforementioned disconnection state between the first energy storage module 102, the second energy storage module 103 and the freewheeling module 104, and the maintenance state of the inductor current, the third and fourth sets of switching elements can be functionally distinguished. For example, the third set of switching elements is used to achieve the disconnection state between the first energy storage module 102 and the freewheeling module 104, as well as the disconnection state between the second energy storage module 103 and the freewheeling module 104, while the fourth set of switching elements is used to achieve the maintenance state of the inductor current. The specific settings can be configured by those skilled in the art according to the actual situation, and this application does not impose any restrictions.

[0052] The switching elements in the third set of switching elements are respectively disposed between the first energy storage module 102 and the freewheeling module 104 and between the second energy storage module 103 and the freewheeling module 104, so as to realize the connection or disconnection between the first energy storage module 102 and the freewheeling module 104 and the connection or disconnection between the second energy storage module 103 and the freewheeling module 104.

[0053] Optionally, the freewheeling module 104 may further include a freewheeling unit. The switching elements of the fourth set of switching elements are respectively disposed between the freewheeling unit and the inductor. The freewheeling unit is used to maintain the inductor current at the target current. The freewheeling unit may include energy storage elements such as capacitors. When the fourth set of switching elements is turned on, the energy storage element can store the charge at the inductor. When the fourth set of switching elements is turned off, the energy stored in the energy storage element can be released to the inductor. Alternatively, it may be a ground terminal. When only the fourth set of switching elements is turned on, a freewheeling loop can be formed between the ground terminal and the inductor. In this freewheeling loop, the inductor current can be in a state where the difference between the current and the target current is less than or equal to the current threshold.

[0054] In some embodiments, the multiple switching elements in the first energy storage module 102 and the second energy storage module 103 are field-effect transistors; the multiple switching elements in the freewheeling module 104 are field-effect transistors.

[0055] In the aforementioned charge pump, after the current in the inductor in the charge pump increases to the target current, the freewheeling module 104 keeps the inductor in a state where the difference between the current and the target current is less than or equal to the current threshold. This allows the energy stored in the switching elements to be released through the resonant circuit formed by the first energy storage module 102, the second energy storage module 103, and the freewheeling module 104 when multiple switching elements in the first energy storage module 102 and the second energy storage module 103 are disconnected. This ensures that the voltage difference across the multiple switching elements in the first energy storage module 102 and the second energy storage module 103 is reduced before the switching elements are switched on, thereby reducing switching losses and improving conversion efficiency.

[0056] In some embodiments, the control module 101 controls the first and second sets of switching elements in the first energy storage module 102 and the second energy storage module 103 to periodically turn on or off, and controls the third and fourth sets of switching elements in the freewheeling module 104 to periodically turn on or off, including:

[0057] The control module 101 controls the first set of switching elements, the second set of switching elements, the third set of switching elements, and the fourth set of switching elements to periodically turn on or off according to different timing sequences.

[0058] In this configuration, the switching elements in the first and second sets of switching elements are not simultaneously turned on, and the switching elements in the third and fourth sets of switching elements are not simultaneously turned on.

[0059] It should be understood that the first and second sets of switching elements are turned on at different time periods. That is, the conduction time periods of the first and second sets of switching elements do not overlap. For example, if the first set of switching elements begins to conduct at time t1, its conduction time is t1 to t1+N1, where N1 is the conduction duration of the first set of switching elements. The conduction time period of the second set of switching elements is t1+M to t1+M+N2, where M>N1 and N2 is the conduction duration of the second set of switching elements. The third and fourth sets of switching elements do not conduct simultaneously for the same reason, and will not be elaborated further here.

[0060] Optionally, the value of the time period after the first set of switching elements is turned off and before the second set of switching elements is turned on, i.e., M-N1, can be set by those skilled in the art according to the actual situation. In some embodiments, a conventional few nanoseconds to tens of nanoseconds can be used, and this application does not impose any restrictions.

[0061] It should be understood that the order in which the third and fourth switch element sets are turned on corresponds to the functional execution order of maintaining the inductor current at the target current and then releasing the electrical energy stored in the switch elements of the first and second switch element sets through the resonant circuit. For example, if the third switch element set is used to realize the disconnection state between the first energy storage module 102 and the freewheeling module 104 and the second energy storage module 103 and the freewheeling module 104, and the fourth switch element set is used to realize the maintenance state of the inductor current, then the control module 101 needs to first control the third switch element set to turn on and the fourth switch element set to turn off, so that the inductor current increases to the target current, and then control the fourth switch element set to turn on and the third switch element set to turn off, so that the inductor current is in a state where the difference between the target current and the target current is less than or equal to the current threshold.

[0062] In the aforementioned charge pump, by setting the third set of switching elements and the fourth set of switching elements to not be turned on at the same time, the function of the freewheeling module 104 can be specifically realized: after maintaining the inductor current at the target current, the electrical energy stored in the switching elements of the first set of switching elements and the second set of switching elements can be released through the resonant circuit.

[0063] In some embodiments, the timing for controlling the periodic on or off of the third set of switching elements includes a first on-time for controlling the third set of switching elements to be on, the first on-time including a first sub-time and a second sub-time, both of which are positively correlated with the target current;

[0064] Specifically, when the third set of switching elements is in the first sub-time period, the current in the inductor gradually increases to the target current; when the third set of switching elements is in the second sub-time period, the current in the inductor decreases from the target current to zero.

[0065] It should be understood that when the third set of switching elements is turned on, the input current flows through the inductor via the first energy storage module 102 or the second energy storage module 103 to increase the inductor current. Therefore, when the third set of switching elements is turned on, the inductor current gradually increases from zero to the target current for a first sub-duration, and the energy stored in the switching elements of the first and second sets of switching elements is released through the resonant circuit, i.e., the inductor current decreases from the target current to zero for a second sub-duration.

[0066] The first and second sub-durations are both positively correlated with the target current; that is, the larger the target current, the longer the first and second sub-durations. In some embodiments, the execution order of the first and second sub-durations can be alternated within one conduction cycle T of the third set of switching elements. For example, the first sub-duration, in which the inductor current gradually increases from zero to the target current, can be executed first, followed by the second sub-duration, or the second sub-duration, in which the inductor current gradually increases from zero to the target current, can be executed first, followed by the first sub-duration.

[0067] Exemplary, in one embodiment, such as Figure 5A As shown, within one conduction cycle T of the third set of switching elements, the third set of switching elements is first turned on for a first sub-duration. During this process, the inductor current gradually increases from zero to the target current. After the conduction process of the fourth set of switching elements is completed, and the inductor current is maintained at the target current, the third set of switching elements is finally turned on for a second sub-duration. During this process, the inductor current decreases from the target current to zero. In another embodiment, as... Figure 5B As shown, the third set of switching elements is first turned on for the second sub-duration. During this process, the inductor current drops from the target current to zero. Then, the third set of switching elements is turned on for the first sub-duration. During this process, the inductor current gradually increases from zero to the target current. That is, the execution order of the first sub-duration and the second sub-duration is different according to the different time periods of the turn-on cycle of the third set of switching elements.

[0068] It should be noted that the zero value that the inductor current eventually reaches can be an approximation of zero, such as 0.6, 0.4, etc. The specific value is determined according to the parasitic parameters of each device in the actual circuit, and this application does not impose any restrictions.

[0069] In the aforementioned charge pump, by setting the current of the inductor to gradually increase to the target current when the third set of switching elements is in the first sub-time period, and the current of the inductor to drop from the target current to zero when the third set of switching elements is in the second sub-time period, it is possible to further realize the function of releasing the electrical energy stored in the switching elements of the first and second sets of switching elements when both switching elements in the first and second sets of switching elements are disconnected.

[0070] In some embodiments, the control timing diagram of the fourth set of switching elements is as follows: Figure 6 As shown, the timing sequence for controlling the periodic on or off of the fourth set of switching elements includes a second on-time for controlling the fourth set of switching elements to be on.

[0071] Specifically, when the fourth set of switching elements is in the second conduction period, the current of the inductor is in a state where the difference between the current and the target current is less than or equal to the current threshold.

[0072] It should be understood that when the fourth set of switching elements is in the second conduction period, the third set of switching elements is in the off state, so as to ensure that the difference between the inductor current and the target current is less than or equal to the current threshold. Furthermore, before the fourth set of switching elements is in the conduction state, the third set of switching elements needs to be in the conduction period for a first sub-term to increase the inductor current to the target current.

[0073] In some embodiments, such as Figure 7 As shown, the timing sequence for controlling the periodic on or off of the first set of switching elements includes a reference on-time for controlling the first set of switching elements to be on. The difference between the sum of the reference on-time and the target on-time is less than or equal to a duration threshold. The sum of the target on-time is the sum of the first sub-on-time and the second on-time.

[0074] It should be understood that the inductor current only increases when the input electrical signal is input through the first energy storage module 102, i.e., when the first switching element of the first energy storage module 102 is turned on. The reference conduction time of the first switching element set is necessary to ensure that the charge pump can output the regulated electrical signal according to the preset voltage regulation ratio when performing voltage regulation. That is, the reference conduction time here adopts the conduction time in related technologies, which is a fixed value. In order to release the electricity stored in the switching elements of the first and second switching element sets before the second switching element set is turned on, the inductor current needs to be maintained after the target current is reached and after the first switching element set is turned off and before the second switching element set is turned on. That is, the sum of the first sub-time and the second conduction time needs to be greater than or equal to the reference conduction time for controlling the first switching element set to turn on.

[0075] It should be noted that the specific values ​​of the above-mentioned duration thresholds shall be set by those skilled in the art according to the actual situation, and this application does not impose any restrictions.

[0076] In the aforementioned charge pump, by setting the difference between the reference conduction duration and the sum of the first sub-duration and the second conduction duration to be less than or equal to the duration threshold, it can be ensured that the inductor current is maintained after the target current reaches the first set of switching elements and before the second set of switching elements is turned on, so as to release the charge stored in the switching elements of the first set of switching elements and the second set of switching elements before the second set of switching elements is turned on.

[0077] In some embodiments, such as Figure 8As shown, the conduction start position of the second set of switching elements is adjacent to the conduction end position of the first set of switching elements, and the difference between the conduction start position of the second set of switching elements and the conduction end position of the first set of switching elements is greater than or equal to the second sub-duration.

[0078] It should be understood that, in order to ensure that the electrical charge stored in the switching elements of the first and second switching element sets is released before the second switching element set is turned on, i.e., the inductor current drops to zero, the time difference between the start position of the second switching element set and the end position of the first switching element set must include at least the second sub-time.

[0079] In some embodiments, the time difference between the conduction start position of the second set of switching elements and the conduction end position of the first set of switching elements may include, in addition to the second sub-time, the switching time from the conduction of the third set of switching elements to the conduction of the fourth set of switching elements. Ideally, the switching time from the conduction of the third set of switching elements to the conduction of the fourth set of switching elements is close to zero, and is specifically determined by the control delay corresponding to the switching element.

[0080] It should be noted that the specific value of the target difference between the above difference and the second sub-duration can be set by those skilled in the art according to the actual situation, and this application does not impose any restrictions.

[0081] In the aforementioned charge pump, by setting the difference between the conduction start position of the second set of switching elements and the conduction end position of the first set of switching elements to be greater than or equal to the second sub-duration, sufficient time leeway can be provided for the current reduction process of the inductor current dropping to zero, ensuring the full implementation of the current reduction process.

[0082] In some embodiments, the freewheeling module 104 is used to gradually increase the current in the inductor to a target current under the control of the control module 101, including:

[0083] When the target switch element set in the first set of switch elements and the second set of switch elements is turned on, and the third set of switch elements is in the first sub-time period, the current in the energy storage module corresponding to the target switch element set flows through the inductor to another energy storage module in the first energy storage module 102 and the second energy storage module 103. The inductor stores electrical energy so that the current in the inductor gradually increases to the target current.

[0084] It should be understood that the aforementioned target set of switching elements can be either a first set of switching elements or a second set of switching elements. The specific target set of switching elements is determined by whether the input electrical signal flows into the first energy storage module 102 or the second energy storage module 103. For example, if the first set of switching elements includes the first switching elements of the first energy storage module 102 and the second set of switching elements includes the second switching elements of the second energy storage module 103, when the target set of switching elements is the first set of switching elements, the input electrical signal flows into the first energy storage module 102; when the target set of switching elements is the second set of switching elements, the input electrical signal flows into the second energy storage module 103.

[0085] In the aforementioned charge pump, by specifically setting the target switching element set in the first and second switching element sets to be turned on, and the third switching element set being in the first sub-time period, the current in the energy storage module corresponding to the target switching element set flows through the inductor to another energy storage module in the first energy storage module 102 and the second energy storage module 103, and the inductor stores electrical energy so that the current in the inductor gradually increases to the target current.

[0086] In some embodiments, such as Figure 9 As shown, each switch element in the third and fourth switch element sets includes a parasitic capacitance for storing electrical energy; each switch element in the fourth switch element set is also connected to ground.

[0087] The freewheeling module 104, under the control of the control module 101, maintains the inductor current in a state where the difference between the current and the target current is less than or equal to a current threshold, including:

[0088] Before the target set of switching elements is turned on, the third set of switching elements is turned off, and the fourth set of switching elements is turned on, the parasitic capacitance of the switching elements in the third set of switching elements provides the stored electrical energy to the inductor so as to keep the current of the inductor in a state where the difference between the current and the target current is less than or equal to the current threshold.

[0089] When the target switching element set and the fourth switching element set are turned on, the switching elements in the fourth switching element set form a freewheeling loop with the ground terminal to keep the current of the inductor in a state where the difference between the current and the target current is less than or equal to the current threshold.

[0090] With all switching element sets off, the parasitic capacitance of the switching elements in the fourth switching element set provides the stored electrical energy to the inductor, so as to keep the inductor current in a state where the difference between the current and the target current is less than or equal to the current threshold.

[0091] The third set of switching elements includes at least a first subset connected to the inductor and the first energy storage module 102, and a second subset connected to the inductor and the second energy storage module 103, respectively, to increase the inductor current when the third set of switching elements is turned on. The fourth set of switching elements includes at least a first subset connected to a first terminal of the inductor and ground, respectively, and a second subset connected to a second terminal of the inductor and ground, respectively, to form a freewheeling loop between the inductor and ground when the fourth set of switching elements is turned on.

[0092] It should be understood that, such as Figure 6 As shown, there is a dead time before the third set of switching elements is turned off and the fourth set of switching elements is turned on. During this time, both the third and fourth sets of switching elements are turned off, and the inductor current freewheels through the parasitic capacitance of the switching elements in the third set of switching elements. This time period is very short, typically a few nanoseconds to tens of nanoseconds. Since the target set of switching elements remains on, the current flow direction at the first energy storage module 102 or the second energy storage module 103 is still the same as at the previous moment.

[0093] After the target switching element set and the fourth switching element set are turned on, the inductor current continues through the freewheeling loop formed by the fourth switching element set and the ground terminal. Under the influence of the low on-resistance of the fourth switching element set, the inductor current decreases at a small slope, but the decrease will not cause the difference between the inductor current and the target current to exceed the current threshold. At this time, the current flow direction at the first energy storage module 102 or the second energy storage module 103 is still the same as at the previous moment.

[0094] When all the switching elements are disconnected, the inductor current continues through the parasitic capacitance of the switching elements in the fourth switching element set. This period is very short, typically a few nanoseconds to tens of nanoseconds. During this time, no current flows through the first energy storage module 102 and the second energy storage module 103.

[0095] In the aforementioned charge pump, the inductor current is allowed to continue flowing through parasitic capacitance and freewheeling circuit at different control times, so as to ensure that the inductor current can maintain the target current until the third set of switching elements is turned on.

[0096] In some embodiments, each switch in the first and second sets of switching elements includes a parasitic capacitance for storing electrical energy; the first energy storage module 102, the second energy storage module 103, and the freewheeling module 104 are further configured to form a resonant circuit when all the switching elements in the first and second sets of switching elements are disconnected, releasing the electrical energy stored in the switching elements in the first and second sets of switching elements until the voltage difference across the switching elements in the first and second sets of switching elements is less than or equal to a voltage threshold, including:

[0097] When all the switching elements in the first and second sets of switching elements are off and the third set of switching elements is on, the capacitors in the first and second energy storage modules 102 and 103, the parasitic capacitances and inductances of the switching elements in the first and second sets of switching elements, and all the switching elements in the third set of switching elements form a resonant circuit, releasing the electrical energy stored in the switching elements in the first and second sets of switching elements until the voltage difference across the switching elements in the first and second sets of switching elements is less than or equal to the voltage threshold.

[0098] It should be understood that the above resonant circuit is an LC series resonant circuit, and the current can be used to eliminate the charge stored in the parasitic capacitance of the switching elements in the resonant circuit.

[0099] Optionally, the above method for determining whether the voltage difference across the switching elements in the first set of switching elements and the second set of switching elements is less than or equal to the voltage threshold can be to collect the voltage difference across each switching element in the resonant circuit by a voltage detector. For example, when the control module 101 determines that the collected voltage difference value is less than or equal to the voltage threshold, it can determine that the release of electrical energy stored in the switching elements in the resonant circuit is complete. Alternatively, it can be determined whether the voltage difference across the switching elements in the first set of switching elements and the second set of switching elements is less than or equal to the voltage threshold by whether the body diode in the switching element is conducting.

[0100] For example, with Figure 4 Taking the charge pump shown as an example, when the switching elements in the first and second sets of switching elements are both off, only the third set of switching elements is turned on. The inductor and the parasitic capacitances of all the switching transistors except the third set of switching elements form an LC series resonance, thereby generating a resonant current. This resonant current is used to release the charge stored in the parasitic capacitance until the voltage difference across the switching elements in the first and second sets of switching elements drops to zero.

[0101] In some embodiments, both the first energy storage module 102 and the second energy storage module 103 include at least two capacitors. Each switch in the first and second set of switching elements also includes a body diode connected in parallel with the parasitic capacitance. The capacitors in the first and second energy storage modules 102 and 103, the parasitic capacitances and inductances of the switching elements in the first and second sets of switching elements, and all the switching elements in the third set of switching elements form a resonant circuit, including:

[0102] Partial capacitors in the first energy storage module 102 and the second energy storage module 103, parasitic capacitances and inductances of partial switching elements in the first and second switching element sets, and all switching elements in the third switching element set form a resonant circuit to release the electrical energy stored in partial switching elements in the first and second switching element sets until the body diode in partial switching elements is turned on.

[0103] In some switching elements, the conduction direction of the body diode of each switching element is consistent with the current direction of the resonant circuit.

[0104] It should be understood that since the switching element includes parasitic capacitance and body diode, when the charge stored in the parasitic capacitance is released to zero, the body diode conducts. When the body diode conducts, the inductor current drops to zero. Because the body diode has unidirectional conductivity, after the body diode conducts, the voltage difference across the switching element is zero, as the conduction direction of the body diode is consistent with the current direction of the resonant circuit. This achieves soft turn-on of the switching element.

[0105] In one embodiment, based on Figure 4 The charge pump shown can be divided into 10 time periods (t1~t10) per cycle, and the control timing diagram for each cycle is as follows. Figure 10 As shown, where:

[0106] Time period t1: During this time period, the second set of switching elements is off, the first set of switching elements is on, the third set of switching elements Q8A and Q8B is on, and the fourth set of switching elements Q9A and Q9B is off. The current flow in the first energy storage module 102 and the current flow in the inductor are as follows: Figure 11 As shown, the input electrical signal flows into the first energy storage module 102 via the first switching transistor Q1A and is then transmitted through two branches. One branch transmits the signal within the first energy storage module 102, passing sequentially through the first capacitor C1A and the second capacitor C2A, and is output at the output terminal. The other branch transmits the signal through the freewheeling module 104 and flows through the inductor to the second energy storage module 103. During this time period, the inductor stores energy in the forward direction, and the current increases. The time period t1 ends after the current reaches the target current.

[0107] Time period t2: During this time period, the second set of switching elements remains off, while the first set of switching elements remains on. The third set of switching elements Q8A and Q8B are off, and the fourth set of switching elements Q9A and Q9B are off; this is the dead time for the third and fourth sets of switching elements. The inductor current freewheels through the parasitic capacitance of the third set of switching elements Q8A and Q8B. This time period is very short, and the current flow direction in the first energy storage module 102 and the inductor is the same as in time period t1.

[0108] During time period t3: The second set of switching elements remains off, while the first set of switching elements remains on. The third set of switching elements Q8A and Q8B is off, and the fourth set of switching elements Q9A and Q9B is on. The inductor current freewheels through the fourth set of switching elements Q9A and Q9B. When the on-resistance of the fourth set of switching elements Q9A and Q9B is relatively low, the inductor current remains essentially constant (in actual circuits, the inductor current decreases at a very small slope). The current flow direction in the first energy storage module 102 and the inductor current flow direction are as follows: Figure 12 As shown, the current flow direction in the first energy storage module 102 is the same as the current flow direction in time period t1, and the current flow direction of the inductor is transmitted in the fourth set of switching elements Q9A and Q9B and the ground terminal.

[0109] Time period t4: During this time period, all switching elements are turned off. The inductor current freewheels through the parasitic capacitances of the fourth switching element set, Q9A and Q9B. This time period is very short. The current flow direction of the inductor is as follows... Figure 13 As shown, only the current flow of the inductor is transmitted in the fourth switching element set Q9A and Q9B and the ground terminal.

[0110] Time period t5: During this time period, only the third switching element set, Q8A and Q8B, are turned on. The inductor and the parasitic capacitances of all MOSFETs except the third switching element set, Q8A and Q8B, form an LC series resonance. The direction of the resonant current is as follows... Figure 14 As shown. This resonant current is used to release the energy of the parasitic capacitance of all MOS transistors except for the third switching element sets Q8A and Q8B, until their body diodes conduct. When the body diodes conduct, the inductor current drops to 0, and the time period t5 ends.

[0111] During time period t6: The second set of switching elements begins to conduct. Since the conduction direction of the body diodes is consistent with the current direction of the resonant circuit, the body diodes of Q2A, Q3A, Q1B, Q4B, and Q7B are in the conducting state. Therefore, the voltage difference between their drain and source is about -0.6V, close to 0V, which reduces the conduction loss of the switching transistors when they are turned on.

[0112] Because the circuit is symmetrical, the time period t6~t10 operates on the same principle as t1~t5. Figure 10 As can be seen, during the time period t6 to t10, the current flow direction of the inductor is opposite to that during the time period t1. Similarly, it can be seen that Q2B, Q3B, Q1A, Q4A, and Q7A, whose conduction direction of the body diode is consistent with the current direction of the resonant circuit, also achieve soft turn-on when turned on.

[0113] It should be understood that the phrases "one embodiment," "an embodiment," or "some embodiments" mentioned throughout the specification mean that a specific feature, structure, or characteristic related to an embodiment is included in at least one embodiment of this application. Therefore, "in one embodiment," "in one embodiment," or "in some embodiments" appearing throughout the specification do not necessarily refer to the same embodiment. Furthermore, these specific features, structures, or characteristics can be combined in any suitable manner in one or more embodiments. It should be understood that in the various embodiments of this application, the sequence numbers of the above-described processes do not imply a sequential order of execution; the execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application. The sequence numbers of the above-described embodiments are merely for descriptive purposes and do not represent the superiority or inferiority of the embodiments. The descriptions of the various embodiments above tend to emphasize the differences between the various embodiments; their similarities or commonalities can be referred to mutually, and for the sake of brevity, they will not be repeated here.

[0114] In this article, the term "and / or" is merely a description of the relationship between related objects, indicating that there can be three kinds of relationships. For example, object A and / or object B can represent three situations: object A exists alone, object A and object B exist simultaneously, and object B exists alone.

[0115] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0116] In the several embodiments provided in this application, it should be understood that the disclosed devices and methods can be implemented in other ways. The embodiments described above are merely illustrative. For example, the division of modules is only a logical functional division, and in actual implementation, there may be other division methods, such as: multiple modules or components can be combined, or integrated into another system, or some features can be ignored or not executed. In addition, the coupling, direct coupling, or communication connection between the various components shown or discussed can be through some interfaces, and the indirect coupling or communication connection between devices or modules can be electrical, mechanical, or other forms.

[0117] The modules described above as separate components may or may not be physically separate. The components shown as modules may or may not be physical modules. They may be located in one place or distributed across multiple network units. Some or all of the modules may be selected to achieve the purpose of this embodiment according to actual needs.

[0118] In addition, each functional module in the various embodiments of this application can be integrated into one processing unit, or each module can be a separate unit, or two or more modules can be integrated into one unit; the integrated modules can be implemented in hardware or in the form of hardware plus software functional units.

[0119] Those skilled in the art will understand that all or part of the steps of the above method embodiments can be implemented by hardware related to program instructions. The aforementioned program can be stored in a computer-readable storage medium. When the program is executed, it performs the steps of the above method embodiments. The aforementioned storage medium includes various media that can store program code, such as mobile storage devices, read-only memory (ROM), magnetic disks, or optical disks.

[0120] Alternatively, if the integrated units described above are implemented as software functional modules and sold or used as independent products, they can also be stored in a computer-readable storage medium. Based on this understanding, the technical solutions of the embodiments of this application, or the parts that contribute to related technologies, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause an electronic device to execute all or part of the methods described in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as mobile storage devices, ROMs, magnetic disks, or optical disks.

[0121] The methods disclosed in the several method embodiments provided in this application can be arbitrarily combined without conflict to obtain new method embodiments.

[0122] The features disclosed in the several product embodiments provided in this application can be arbitrarily combined without conflict to obtain new product embodiments.

[0123] The features disclosed in the several method or device embodiments provided in this application can be arbitrarily combined without conflict to obtain new method or device embodiments.

[0124] The above description is merely an embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A charge pump, characterized in that, The charge pump includes a control module, a freewheeling module, a first energy storage module, and a second energy storage module. The freewheeling module includes an inductor and multiple switching elements. Both the first and second energy storage modules include capacitors and multiple switching elements. The freewheeling module is connected to both the first and second energy storage modules. The control module is connected to the freewheeling module, the first energy storage module, and the second energy storage module, respectively. The control module is used to control the first and second sets of multiple switching elements in the first and second energy storage modules to periodically turn on or off, and to control the third and fourth sets of multiple switching elements in the freewheeling module to periodically turn on or off. The freewheeling module is used to gradually increase the current of the inductor to the target current under the control of the control module, and then periodically turn the third set of switching elements and the fourth set of switching elements on or off to keep the current of the inductor in a state where the difference between the current and the target current is less than or equal to the current threshold. The first energy storage module, the second energy storage module, and the freewheeling module are further configured to form a resonant circuit when the switching elements in the first set of switching elements and the second set of switching elements are all disconnected and the third set of switching elements is on, thereby releasing the electrical energy stored in the switching elements in the first set of switching elements and the second set of switching elements until the voltage difference across the switching elements in the first set of switching elements and the second set of switching elements is less than or equal to a voltage threshold. The timing sequence for controlling the periodic on / off of the third set of switching elements includes a first on-time controlling the third set of switching elements to be on, the first on-time including a first sub-time and a second sub-time, both of which are positively correlated with the target current; wherein, when the third set of switching elements is in the first sub-time, the current of the inductor gradually increases to the target current; when the third set of switching elements is in the second sub-time, the current of the inductor decreases from the target current to zero; The timing for controlling the periodic on or off of the fourth set of switching elements includes a second on-time for controlling the fourth set of switching elements to be on; wherein, when the fourth set of switching elements is in the second on-time, the current of the inductor is in a state where the difference between the current and the target current is less than or equal to the current threshold.

2. The charge pump as claimed in claim 1, characterized in that, The control module controls the first and second sets of switching elements in the first and second energy storage modules to periodically turn on or off, and controls the third and fourth sets of switching elements in the freewheeling module to periodically turn on or off, including: The control module controls the first set of switching elements, the second set of switching elements, the third set of switching elements, and the fourth set of switching elements to periodically turn on or off according to different timing sequences. Specifically, the switching elements in the first set of switching elements and the second set of switching elements are not simultaneously turned on, and the switching elements in the third set of switching elements and the fourth set of switching elements are not simultaneously turned on.

3. The charge pump as claimed in claim 1, characterized in that, The timing for controlling the periodic on or off of the first set of switching elements includes a reference on-time for controlling the first set of switching elements to be on. The difference between the reference on-time and the sum of the target on-time is less than or equal to a duration threshold. The sum of the target on-time is the sum of the first sub-on-time and the second on-time.

4. The charge pump as described in claim 3, characterized in that, The conduction start position of the second set of switching elements is adjacent to the conduction end position of the first set of switching elements, and the difference between the conduction start position of the second set of switching elements and the conduction end position of the first set of switching elements is greater than or equal to the second sub-duration.

5. The charge pump according to any one of claims 1-4, characterized in that, The freewheeling module, under the control of the control module, is used to gradually increase the current in the inductor to a target current, including: When the target set of switching elements in the first set of switching elements and the second set of switching elements is turned on, and the third set of switching elements is in the first sub-time period, the current in the energy storage module corresponding to the target set of switching elements flows through the inductor to another energy storage module in the first and second energy storage modules. The inductor stores electrical energy so that the current in the inductor gradually increases to the target current.

6. The charge pump as claimed in claim 5, characterized in that, Each switch element in the third and fourth switch element sets includes a parasitic capacitance for storing electrical energy; each switch element in the fourth switch element set is also connected to ground. The freewheeling module, under the control of the control module, is used to maintain the current of the inductor in a state where the difference between the current and the target current is less than or equal to a current threshold, including: Before the target set of switching elements is turned on, the third set of switching elements is turned off, and the fourth set of switching elements is turned on, the parasitic capacitance of the switching elements in the third set of switching elements provides the stored electrical energy to the inductor, so as to keep the current of the inductor in a state where the difference between the current and the target current is less than or equal to the current threshold. When the target switching element set and the fourth switching element set are turned on, the switching element in the fourth switching element set forms a freewheeling loop with the ground terminal to keep the current of the inductor in a state where the difference between the current and the target current is less than or equal to the current threshold. With all switching element sets off, the parasitic capacitance of the switching elements in the fourth switching element set provides the stored electrical energy to the inductor to keep the current of the inductor in a state where the difference between the current and the target current is less than or equal to the current threshold.

7. The charge pump as claimed in claim 6, characterized in that, Each switching element in the first and second sets of switching elements includes a parasitic capacitance for storing electrical energy. The first energy storage module, the second energy storage module, and the freewheeling module are further configured to form a resonant circuit when all switching elements in the first and second sets of switching elements are disconnected and the third set of switching elements is on, releasing the electrical energy stored in the switching elements of the first and second sets of switching elements until the voltage difference across the switching elements in the first and second sets of switching elements is less than or equal to a voltage threshold, including: When all the switching elements in the first and second sets of switching elements are off, and the third set of switching elements is on, the capacitors in the first and second energy storage modules, the parasitic capacitances of the switching elements in the first and second sets of switching elements, the inductors, and all the switching elements in the third set of switching elements form the resonant circuit, releasing the electrical energy stored in the switching elements in the first and second sets of switching elements until the voltage difference across the switching elements in the first and second sets of switching elements is less than or equal to a voltage threshold.

8. The charge pump as claimed in claim 7, characterized in that, Both the first and second energy storage modules include at least two capacitors. Each switch in the first and second set of switching elements further includes a body diode connected in parallel with the parasitic capacitance. The capacitors in the first and second energy storage modules, the parasitic capacitances of the switching elements in the first and second set of switching elements, the inductor, and all the switching elements in the third set of switching elements form the resonant circuit, including: The partial capacitors in the first and second energy storage modules, the parasitic capacitances of some switching elements in the first and second switching element sets, the inductor, and all switching elements in the third switching element set form the resonant circuit, releasing the electrical energy stored in the partial switching elements in the first and second switching element sets until the body diode in the partial switching elements is turned on. The conduction direction of the body diode of each of the aforementioned switching elements is consistent with the current direction of the resonant circuit.

9. The charge pump as claimed in claim 1, characterized in that, The multiple switching elements in the first energy storage module and the second energy storage module are field-effect transistors; the multiple switching elements in the freewheeling module are field-effect transistors.

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