Charging circuit and control method thereof

Abstract

The invention discloses a charging circuit which comprises an overvoltage protection circuit, a charge pump circuit, a switch control circuit and a linear control circuit. Wherein a linear current channel circuit is arranged between the charge pump input end and the output voltage end. When the charging circuit works in a switching mode, a power tube in the charge pump circuit is controlled by a switching control signal to be switched on and switched off, so that the charge pump circuit charges a load of the charging circuit, and when the charging circuit works in a linear mode, a power tube in the linear current channel circuit works in the linear mode, so that the charge pump circuit charges the load of the charging circuit. A current channel from an input voltage end to an output voltage end is provided. According to the charging circuit, on the premise that high-power charging is achieved through the charge pump circuit, low-power charging in partial states is achieved by controlling the switches of the charge pump circuit, the circuit design is simplified, and the circuit cost is reduced.

Description

Technical Field

[0001] The present application relates to the field of power electronics technology, and in particular to a charging circuit and a corresponding control method. Background Art

[0002] With the popularity of fast charging, mid-range and high-end mobile phones and other mobile devices are generally equipped with fast charging functions. Charge pump circuits have been widely used in the field of fast charging technology due to their high charging efficiency. Figure 1 The figure shows an existing battery fast charging system 100, which includes an inductive switching power supply circuit 101 and a charge pump circuit 102. In the fast charging stage of the battery, the charge pump circuit 102 charges the battery 103 at high power. When the battery power is extremely low, the inductive switching power supply circuit 101 is required to trickle charge the battery 103 until the voltage of the battery 103 reaches a certain value, and then the charge pump circuit 102 is used for high-power charging. In addition, some mobile phones need to be inserted into an adapted fast charging charger before the charge pump circuit 102 will work. Otherwise, it will only be charged through the inductive switching power supply circuit 102, and fast charging cannot be achieved. Summary of the Invention

[0003] The present application provides a charging circuit that, while utilizing a charge pump circuit to achieve high-power charging, achieves low-power charging in some states by controlling the switches of the charge pump circuit itself, thereby simplifying the circuit design and reducing the circuit cost.

[0004] According to one embodiment of the present invention, a charging circuit is provided, comprising: a charge pump circuit having a first end, a second end and a ground end, wherein the first end is coupled to the charge pump input end, the second end is coupled to the output voltage end, the charge pump input end receives a charge pump input voltage, and the output voltage end provides an output voltage, the charge pump circuit comprises a linear current channel circuit; a linear control circuit provides a first linear control signal to the linear current channel circuit to enable the charge pump circuit to operate in a linear mode, in which the power tubes in the linear current channel circuit are turned on under the control of the first linear control signal, and the remaining power tubes in the charge pump circuit are turned off; wherein the charge pump circuit also receives a charge pump control signal, and when the charge pump circuit operates in a switching mode, the charge pump control signal controls the power tubes in the charge pump circuit to be turned on or off.

[0005] According to one embodiment of the present invention, a control method for a charging circuit is provided, wherein the charging circuit includes a charge pump circuit, and the charge pump circuit includes a charge pump power tube. The control method includes: determining an operating mode of the charging circuit, wherein: if the charging circuit operates in a switching mode, controlling the charge pump circuit to operate in the switching mode; and if the charging circuit operates in a linear mode, controlling a linear current channel circuit in the charge pump circuit to operate in a linear mode, wherein the linear current channel circuit includes a charge pump power tube coupled between an input terminal and an output voltage terminal of the charge pump. BRIEF DESCRIPTION OF THE DRAWINGS

[0006] The above and other objects, features and advantages of the present application will become more apparent through the following description of the embodiments of the present application with reference to the accompanying drawings:

[0007] Figure 1 An existing battery fast charging system 100 is shown;

[0008] Figure 2 2 is a schematic diagram of a module structure of a charging circuit 200 according to an embodiment of the present application;

[0009] Figure 3 Schematic diagram of the module structure of a charging circuit 300 according to an embodiment of the present application;

[0010] Figure 4 4 is a schematic diagram of a circuit structure of a linear control circuit 400 according to an embodiment of the present application;

[0011] Figure 5 1 is a schematic diagram of a circuit structure of a linear control circuit 500 according to an embodiment of the present application;

[0012] Figure 6 Schematic diagram of the module structure of a charging circuit 600 according to an embodiment of the present application;

[0013] Figure 7 Schematic diagram of the module structure of a charging circuit 700 according to an embodiment of the present application;

[0014] Figure 8 800 is a schematic diagram of a module structure of a charging circuit according to an embodiment of the present application;

[0015] Figure 9 FIG. 9 is a flow chart of a method 900 for controlling a charging circuit according to an embodiment of the present application. DETAILED DESCRIPTION

[0016] Specific embodiments of the present invention will be described in detail below. It should be noted that the embodiments described herein are for illustrative purposes only and are not intended to limit the present invention. In the following description, numerous specific details are set forth to provide a thorough understanding of the present invention. However, it will be apparent to one of ordinary skill in the art that these specific details are not necessarily required to practice the present invention. In other instances, well-known circuits, materials, or methods are not described in detail to avoid obscuring the present invention.

[0017] The terms "first," "second," and so forth in the following description are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature identified with "first," "second," and so forth may explicitly or implicitly include one or more of such features. Throughout the description of this application, unless otherwise specified, "plurality" means two or more.

[0018] In addition, in this application, directional terms such as "upper" and "lower" may be defined including but not limited to the orientation relative to the schematic placement of the components in the drawings. It should be understood that these directional terms may be relative concepts. They are used for relative descriptions and clarifications, and they may change accordingly according to changes in the orientation of the components in the drawings.

[0019] In this application, unless otherwise specified or limited, the term "connection" should be understood broadly. For example, "connection" can mean fixed connection, detachable connection, or integration; it can mean direct connection or indirect connection through an intermediate medium. In addition, the term "coupling" can refer to the method of electrical connection for signal transmission. "Coupling" can mean direct electrical connection or indirect electrical connection through an intermediate medium.

[0020] Figure 2 FIG. 2 is a schematic diagram of a module structure of a charging circuit 200 according to an embodiment of the present application. Figure 2 As shown, charging circuit 200 includes an overvoltage protection circuit 201, a charge pump circuit 202, a switch control circuit 203, and a linear control circuit 204. Charging circuit 200 has an input voltage terminal T1 for receiving an input voltage Vusb and an output voltage terminal T2 for providing an output voltage Vout. When charging circuit 200 is used in a charging device to charge a battery, input voltage terminal T1 of charging circuit 200 is connected to a USB port to receive input voltage Vusb from the USB port, and output voltage terminal T2 of charging circuit 200 is coupled to battery 206.

[0021] The overvoltage protection circuit 201 is used to prevent the input voltage Vusb from being too high and damaging the subsequent circuits and loads (battery). Figure 2In the embodiment, the overvoltage protection circuit 201 has a first terminal, a second terminal and a control terminal. The first terminal of the overvoltage protection circuit 201 is coupled to the input voltage terminal T1, the second terminal is coupled to the bus voltage terminal T3, and the control terminal receives an overvoltage protection signal Govp. The overvoltage protection signal Govp is obtained by receiving a voltage based on the input voltage Vusb. When the input voltage Vusb is overvoltage, the subsequent circuit is disconnected from the input voltage Vusb to protect the subsequent circuit. Figure 2 In the embodiment, for clarity of the diagram, the control circuit for providing the overvoltage protection signal Govp to the overvoltage protection circuit 201 is not shown. In one embodiment, a comparison circuit can be used to compare the input voltage Vusb with a reference voltage to obtain the overvoltage protection signal Govp.

[0022] exist Figure 2 In the embodiment, the overvoltage protection circuit 201 includes an overvoltage protection power tube, which is a MOSFET (metal oxide semiconductor field effect tube). It should be understood that other controllable power tubes, such as JFET, etc. can also be used in the overvoltage protection circuit 201. Figure 2 In the embodiment, the drain terminal of the overvoltage protection power transistor MP is coupled to the input voltage terminal T1 , and the source terminal is coupled to the bus voltage terminal T3 .

[0023] The bus voltage terminal T3 provides a bus voltage Vbus, which can be used to power other loads (not shown) in addition to powering the charge pump circuit 202. When the input voltage Vusb is normal and not over-voltage, the first protection switch control signal GS1 of the overvoltage protection circuit 201 is high, and the overvoltage protection circuit 201 is connected to the input voltage terminal T1 and the bus voltage terminal T3. The value of the bus voltage Vbus is almost equal to the value of the input voltage Vusb, and the difference between the two is the turn-on voltage of the overvoltage protection circuit 201, that is, the voltage difference between the first terminal and the second terminal of the overvoltage protection circuit 201. Figure 2 In this embodiment, this is the source-drain voltage of the overvoltage protection power transistor. In other embodiments, the control signal is set according to the structure of the overvoltage protection circuit 201. Generally speaking, when the input voltage Vusb is not overvoltage, the overvoltage protection circuit 201 connects the input voltage terminal T1 and the bus voltage terminal T3. When the input voltage Vusb is overvoltage, the overvoltage protection circuit 201 disconnects the input voltage terminal T1 and the bus voltage terminal T3.

[0024] The overvoltage protection circuit 201 and the charge pump circuit 202 may be integrated into the same chip or into different chips.

[0025] exist Figure 2In an embodiment, the charge pump circuit 202 has a first terminal coupled to the charge pump input terminal T4 and a second terminal coupled to the output voltage terminal T2. The charge pump circuit 202 includes a switch and a capacitor connected in a certain connection manner. Based on the voltage of the charge pump input terminal T4, the charge pump circuit 202 provides an output voltage Vout to the subsequent load, i.e., the battery 206, at the output voltage terminal T2. The bus voltage terminal T3 and the charge pump input terminal T4 can be directly connected or include an intermediate circuit, such as an anti-backflow circuit. Figure 2 In the embodiment, the bus voltage terminal T3 and the charge pump input terminal T4 are directly connected, and the voltage of the charge pump input voltage Vmbus is equal to the voltage of the bus voltage Vbus.

[0026] The charge pump circuit 202 includes a linear current channel circuit 202A. The linear current channel circuit 202A includes a power transistor coupled between the charge pump input terminal T4 and the output voltage terminal T2.

[0027] exist Figure 2 In this embodiment, the switch control circuit 203 has an output terminal that provides a charge pump control signal Vctr to the charge pump circuit 202 to control the charge pump circuit 202 to operate in a switching mode to charge the battery 206. In the switching mode, the power transistors in the charge pump circuit 202 are turned on or off according to a certain regularity. The charge pump control signal Vctr may include multiple switch control signals to control different power transistors in the charge pump circuit 202.

[0028] exist Figure 2 In this embodiment, the linear control circuit 204 has an output terminal that provides a first linear control signal GL1 to the linear current channel circuit 202A, controlling the linear current channel circuit 202A to operate in a linear mode. In the linear mode, the power transistors in the linear current channel circuit 202A operate in the linear region or the saturation region. In this mode, the overvoltage protection circuit 201 and the linear current channel circuit 202A form a current channel between the input voltage terminal T1 and the output voltage terminal T2, thereby charging the battery 206.

[0029] exist Figure 2In one embodiment, the charging circuit 200 further includes a mode determination circuit 205 for controlling the switch control circuit 203 and the linear control circuit 204. When the battery is charging, i.e., when the input voltage terminal T1 is connected to a USB port, the charger and the device (e.g., a mobile phone or tablet) containing the battery 206 perform a handshake operation using a specific communication protocol to determine whether the charging circuit 200 should charge the battery 206 in linear mode or switching mode. The mode determination circuit 205 outputs a mode determination signal Mx for controlling the switch control circuit 203 and the linear control circuit 204. In one embodiment, when the mode determination signal Mx indicates that the charging circuit 200 is operating in linear mode, the switch control circuit 203 stops operating or stops outputting the charge pump control signal Vctr, and the linear control circuit 204 controls the operation of the linear current channel circuit 202A. When the mode determination signal Mx indicates that the charging circuit 200 is operating in switching mode, the linear control circuit 204 stops operating or stops outputting the first linear control signal GL1, and the switch control circuit 203 outputs the charge pump control signal Vctr to control the charge pump circuit 202 in switching mode.

[0030] In some embodiments, the mode determination circuit 205 determines the operating mode of the charging circuit 200 based on circuit parameters, such as the value of the input voltage Vusb or the current at the input voltage terminal T1. In some embodiments, the mode determination circuit 205 controls the operating mode of the charging circuit 200 based on user settings.

[0031] The mode determination circuit 205 can be implemented using analog circuits or digital circuits according to the needs of the application. In some embodiments, the mode determination circuit 205 and the charging circuit 200 are integrated into different chips. In some embodiments, the mode determination signal 205 is given by the upper controller. Figure 2 In the embodiment, the mode determination signal Mx is only used for illustration and is not necessarily an actual signal. The mode determination signal Mx can be an actual signal or a parameter in a register.

[0032] Figure 3 FIG. 3 is a schematic diagram of a module structure of a charging circuit 300 according to an embodiment of the present application. Figure 3 As shown, the charging circuit 300 includes an overvoltage protection circuit 301, a charge pump circuit 302, a backflow prevention circuit 307, a switch control circuit 303, and a linear control circuit 304. The charging circuit 300 has an input voltage terminal T1 for receiving an input voltage Vusb and an output voltage terminal T2 for providing an output voltage Vout. When the charging circuit 300 is used in a charging device to charge a battery, the input voltage terminal T1 of the charging circuit 300 is connected to a USB port to receive the input voltage Vusb from the USB port, and the output voltage terminal T2 of the charging circuit 300 is coupled to the battery 206.

[0033] exist Figure 3 In one embodiment, the overvoltage protection circuit 301 has a first terminal, a second terminal, and a control terminal. The first terminal of the overvoltage protection circuit 301 is coupled to the input voltage terminal T1, the second terminal is coupled to the bus voltage terminal T3, and the control terminal receives the first protection switch control signal GS1, the second linear control signal GL2, and the overvoltage protection signal Govp.

[0034] exist Figure 3 In the embodiment, the overvoltage protection circuit 301 includes a first overvoltage protection power tube MP1 and a second overvoltage protection power tube MP2. The first overvoltage protection power tube MP1 and the second overvoltage protection power tube MP2 are MOSFETs (metal oxide semiconductor field effect transistors). It should be understood that other controllable power tubes, such as JFETs, can also be used in the overvoltage protection circuit 301. The first overvoltage protection power tube MP1 and the second overvoltage protection power tube MP2 both have a source terminal, a drain terminal, and a gate terminal. Figure 3 In the embodiment, the drain terminal of the first overvoltage protection power transistor MP1 is coupled to the input voltage terminal T1, and the source terminal is coupled to the source terminal of the second overvoltage protection power transistor MP2. The drain terminal of the second overvoltage protection power transistor MP2 is coupled to the bus voltage terminal T3. The gate terminals of the first overvoltage protection power transistor MP1 and the second overvoltage protection power transistor MP2 are connected together to receive the first protection switch control signal GS1, the second linear control signal GL2, and the overvoltage protection signal Govp. In some embodiments, the positions of the first overvoltage protection power transistor MP1 and the second overvoltage protection power transistor MP2 are swapped.

[0035] When the charging circuit 300 operates in switching mode, the first overvoltage protection power transistor MP1 and the second overvoltage protection power transistor MP2 remain fully on under the control of the first protection switch control signal GS1, and the input voltage Vusb at the input voltage terminal T1 is slightly higher than the bus voltage Vbus at the bus voltage terminal T3. When the charging circuit 300 operates in linear mode, the first overvoltage protection power transistor MP1 and the second overvoltage protection power transistor MP2 operate in the linear or saturation region under the control of the second linear control signal GL2, providing a current path between the input voltage terminal T1 and the bus voltage terminal T3. The degree of conduction of the first overvoltage protection power transistor MP1 and the second overvoltage protection power transistor MP2 is related to the magnitude of the second linear control signal GL2. When an overvoltage is detected in the input voltage Vusb at the input voltage terminal T1, the overvoltage protection signal Govp shuts down the first overvoltage protection power transistor MP1 and the second overvoltage protection power transistor MP2 to prevent impact on subsequent circuits.

[0036] exist Figure 3In one embodiment, the charge pump circuit 302 has a first terminal coupled to the charge pump input terminal T4 and a second terminal coupled to the output voltage terminal T2. The charge pump circuit 302 includes a first charge pump power transistor MA1, a second charge pump power transistor MB1, a third charge pump power transistor MC1, a fourth charge pump power transistor MD1, and a first flying capacitor Cf1. The first, second, third, and fourth charge pump power transistors MA1, MB1, MC1, and MD1 are coupled in series between the first terminal of the charge pump circuit 302 and a ground terminal GND. The first flying capacitor Cf1 has a first terminal coupled to the connection point between the first and second charge pump power transistors MA1 and MB1, and a second terminal coupled to the connection point between the third and fourth charge pump power transistors MC1 and MD1. The connection point between the second and third charge pump power transistors MB1 and MC1 is coupled to the output voltage terminal T2.

[0037] The charge pump circuit 302 includes a linear current channel circuit 302A. The linear current channel circuit 302A includes a power transistor coupled between the charge pump input terminal T4 and the output voltage terminal T2. Figure 3 In this embodiment, the linear current channel circuit 302A includes a first charge pump power transistor MA1 and a second charge pump power transistor MB1. When the charge pump circuit 302 operates in linear mode, the first charge pump power transistor MA1 and the second charge pump power transistor MB1 are turned on under the control of a first linear control signal GL1. When the charge pump circuit 302 operates in switching mode, the first linear control signal GL1 is not activated, and the first charge pump power transistor MA1, the second charge pump power transistor MB1, the third charge pump power transistor MC1, and the fourth charge pump power transistor MD1 are turned on and off under the control of a first switching control signal GA1, a second switching control signal GB1, a third switching control signal GC1, and a fourth switching control signal GD1, respectively. The first switching control signal GA1, the second switching control signal GB1, the third switching control signal GC1, and the fourth switching control signal GD1 are each one of the charge pump control signals Vctr.

[0038] exist Figure 3In this embodiment, a backflow prevention circuit 307 is included between the bus voltage terminal T3 and the charge pump input terminal T4. This backflow prevention circuit 307 includes an anti-backflow power transistor MZ. This anti-backflow power transistor MZ has a source terminal coupled to the bus voltage terminal T3, a drain terminal coupled to the charge pump input terminal T4, and a gate terminal that receives an anti-backflow control signal Grc. When the charging circuit 300 operates in switching mode, the anti-backflow power transistor MZ remains fully on under the control of the second protection switch control signal GS2, and the bus voltage Vbus at the bus voltage terminal T3 is slightly higher than the charge pump input voltage Vmbus at the charge pump input terminal T4. When the charging circuit 300 operates in linear mode, the anti-backflow power transistor MZ operates in the linear region or saturation region under the control of the third linear control signal GL3, providing a current path between the bus voltage terminal T3 and the charge pump input terminal T4. The degree of conduction of the anti-backflow power transistor MZ is related to the magnitude of the third linear control signal GL3. When a reverse current is detected at the charge pump input terminal T4, or the charge pump input voltage Vmbus is greater than the bus voltage Vbus, the anti-backflow control signal Grc turns off the anti-backflow power tube MZ, thereby preventing the voltage or reverse current at the charge pump input terminal T4 from affecting the bus voltage Vbus.

[0039] It should be understood that in some embodiments, the backflow prevention circuit 307 may also be implemented using other circuits, such as diodes, etc. In this case, the backflow prevention circuit 307 does not need to be controlled by a control signal.

[0040] exist Figure 3In this embodiment, the switch control circuit 303 provides a charge pump control signal Vctr to the charge pump circuit 302 to control the charge pump circuit 302 to operate in a switching mode to charge the battery 206. Furthermore, the switch control circuit 303 outputs a first protection switch control signal GS1 and a second protection switch control signal GS2 to the overvoltage protection circuit 301 and the backflow prevention circuit 307, respectively, to conduct power switching of the power transistors in the overvoltage protection circuit 301 and the backflow prevention circuit 307. In switching mode, the charge pump circuit 302 operates as follows: when the first and third charge pump transistors MA1 and MC1 are turned on, and the second and fourth charge pump transistors MB1 and MD1 are turned off, current flows from the charge pump input terminal T4 through the first charge pump transistor MA1, the first flying capacitor Cf1, and the third charge pump transistor MC1 to the output voltage terminal T2, charging the load battery 206 and the first flying capacitor Cf1. When the first and third charge pump transistors MA1 and MC1 are turned off, and the second and fourth charge pump transistors MB1 and MD1 are turned on, one end of the first flying capacitor Cf1 is connected to the ground terminal GND through the fourth charge pump transistor MD1, while the other end of the first flying capacitor Cf1 is connected to the battery 206 through the second charge pump transistor MB1. Switch control signals GA1, GB1, GC1, and GD1 control the on / off of the first, second, third, and fourth charge pump transistors MA1, MB1, MC1, and MD1, respectively. The switch control circuit 303 may be any existing analog or digital circuit. In some embodiments, the protection switch control signals GS1 and GS2 and the switch control signals GA1, GB1, GC1, and GD1 are provided by independent controller chips.

[0041] exist Figure 3 In this embodiment, the linear control circuit 304 provides a first linear control signal GL1 to the linear current channel circuit 302A, which is used to control the linear current channel circuit 302A to operate in a linear mode, i.e., the first charge pump power transistor MA1 and the second charge pump power transistor MB1 to operate in the linear region or the saturation region. Furthermore, the linear control circuit 304 provides a second linear control signal GL2 to the overvoltage protection circuit 301, which is used to control the overvoltage protection power transistors MP1 and MP2 to operate in the linear region or the saturation region. Furthermore, the linear control circuit 304 provides a third linear control signal GL3 to the backflow prevention circuit 307, which is used to control the backflow prevention power transistor MZ to operate in the linear region or the saturation region. When the charging circuit 300 operates in the linear mode, the linear control circuit 304 controls the overvoltage protection circuit 301, the backflow prevention circuit 307, and the linear current channel circuit 302A in the charge pump circuit 302 to form a current channel for charging the battery 206. In the linear mode, in the charge pump circuit 302 , except for the charge pump power tube in the linear current channel circuit 302A, other charge pump power tubes remain in the off state.

[0042] exist Figure 3 In the embodiment, the charging circuit 300 can also be as follows Figure 2 The embodiment shown includes a mode determination circuit. The working principle of the mode determination circuit has been described above and will not be elaborated here.

[0043] Figure 4 FIG. 4 is a circuit structure diagram of a linear control circuit 400 according to an embodiment of the present application. The linear control circuit 400 can be used in the charging circuit 300. Figure 4 As shown, the linear control circuit 400 includes a first differential adjustment circuit 401, a second differential adjustment circuit 402, and a third differential adjustment circuit 403. The first differential adjustment circuit 401 receives the charge pump input voltage Vmbus and the output voltage Vout, and outputs a first linear control signal GL1 based on the charge pump input voltage Vmbus and the output voltage Vout. The second differential adjustment circuit 402 receives the input voltage Vusb and the bus voltage Vbus, and outputs a second linear control signal GL2 based on the input voltage Vusb and the bus voltage Vbus. The third differential adjustment circuit 403 receives the bus voltage Vbus and the charge pump input voltage Vmbus, and outputs a third linear control signal GL3 based on the bus voltage Vbus and the charge pump input voltage Vmbus.

[0044] exist Figure 4 In one embodiment, the first differential adjustment circuit 401 includes a first differential circuit 401A and a first error amplifier circuit 401B. The first differential circuit 401A receives a charge pump input voltage Vmbus and an output voltage Vout, and based on the charge pump input voltage Vmbus and the output voltage Vout, outputs a first differential voltage Vd1 representing the voltage difference between the charge pump input voltage Vmbus and the output voltage Vout. The first error amplifier circuit 401B receives a first differential voltage reference Vdr1 and a first differential voltage Vd1, and based on the first differential voltage reference Vdr1 and the first differential voltage Vd1, outputs the first linear control signal GL1.

[0045] exist Figure 4 In one embodiment, the second differential adjustment circuit 402 includes a second differential circuit 402A and a second error amplifier circuit 402B. The second differential circuit 402A receives an input voltage Vusb and a bus voltage Vbus, and outputs a second differential voltage Vd2 based on the input voltage Vusb and the bus voltage Vbus, representing the voltage difference between the input voltage Vusb and the bus voltage Vbus. The second error amplifier circuit 402B receives a second differential voltage reference Vdr2 and a second differential voltage Vd2, and outputs a second linear control signal GL2 based on the second differential voltage reference Vdr2 and the second differential voltage Vd2.

[0046] exist Figure 4 In one embodiment, the third differential adjustment circuit 403 includes a third differential circuit 403A and a third error amplifier circuit 403B. The third differential circuit 403A receives the bus voltage Vbus and the charge pump input voltage Vmbus, and outputs a third differential voltage Vd3 based on the bus voltage Vbus and the charge pump input voltage Vmbus, representing the voltage difference between the bus voltage Vbus and the charge pump input voltage Vmbus. The third error amplifier circuit 403B receives a third differential voltage reference Vdr3 and a third differential voltage Vd3, and outputs the third linear control signal GL3 based on the third differential voltage reference Vdr3 and the third differential voltage Vd3.

[0047] exist Figure 4 In the embodiment, the first difference circuit 401A, the second difference circuit 402A, and the third difference circuit 403A may be any existing circuit that can calculate the difference between two input voltage signals. Figure 4 In the embodiments, the input voltage Vusb, bus voltage Vbus, charge pump input voltage Vmbus, and output voltage Vout represent both the actual values of the corresponding voltages and the voltage division values of the corresponding voltages. For example, to meet the input voltage range requirements of each difference circuit, the input voltage Vusb, bus voltage Vbus, charge pump input voltage Vmbus, and output voltage Vout may be one-fifth or one-tenth of the actual voltages, depending on the actual application.

[0048] exist Figure 4In one embodiment, the first error amplifier circuit 401B, the second error amplifier circuit 402B, and the third error amplifier circuit 403B may include error amplifiers. The first linear control signal GL1 is an error amplified signal of the first difference voltage reference Vdr1 and the first difference voltage Vd1. The first error amplifier circuit 401B controls the first charge pump power transistor MA1 and the second charge pump power transistor MB1 in the linear current channel circuit 302A via the first linear control signal GL1, thereby controlling the voltage difference across the linear current channel circuit 302A, that is, the voltage difference between the charge pump input voltage Vmbus and the output voltage Vout, thereby controlling the power consumption and heat dissipation of the linear current channel circuit 302A in the linear mode. The second linear control signal GL2 is an error-amplified signal between the second differential voltage reference Vdr2 and the second differential voltage Vd2. The second error amplifier circuit 402B controls the overvoltage protection power transistors MP1 and MP2 using the second linear control signal GL2, thereby controlling the voltage difference across the overvoltage protection circuit 301, namely, the difference between the input voltage Vusb and the bus voltage Vbus, thereby controlling the power consumption and heat dissipation of the overvoltage protection circuit 301 in the linear mode. The third linear control signal GL3 is an error-amplified signal between the third differential voltage reference Vdr3 and the third differential voltage Vd3. The third error amplifier circuit 403B controls the backflow prevention power transistor MZ using the third linear control signal GL3, thereby controlling the voltage difference across the backflow prevention circuit 307, namely, the difference between the bus voltage Vbus and the charge pump input voltage Vmbus, thereby controlling the power consumption and heat dissipation of the backflow prevention circuit 307 in the linear mode. Any circuit capable of implementing an error amplification function can be used as the error amplifier circuit in the embodiments of the present application.

[0049] Figure 5 FIG. 5 is a circuit structure diagram of a linear control circuit 500 according to an embodiment of the present application. The linear control circuit 500 can be used in the charging circuit 300. Figure 5 As shown, the linear control circuit 500 includes a first differential regulation circuit 501, a second differential regulation circuit 502, and a third differential regulation circuit 503. The first differential regulation circuit 501, the second differential regulation circuit 502, and the third differential regulation circuit 503 may include voltage difference amplifiers.

[0050] exist Figure 5In this embodiment, the first differential adjustment circuit 501 receives the charge pump input voltage Vmbus, the output voltage Vout, a first voltage reference Vr1, and a second voltage reference Vr2. Based on the charge pump input voltage Vmbus, the output voltage Vout, the first voltage reference Vr1, and the second voltage reference Vr2, it outputs a first linear control signal GL1. The first linear control signal GL1 represents an error-amplified signal between the voltage difference between the charge pump input voltage Vmbus and the output voltage Vout and the voltage difference between the first voltage reference Vr1 and the second voltage reference Vr2. The voltage difference amplifier uses the first linear control signal GL1 to control the first charge pump power transistor MA1 and the second charge pump power transistor MB1 in the linear current channel circuit 302A. This controls the voltage difference across the linear current channel circuit 302A, specifically the voltage difference between the charge pump input voltage Vmbus and the output voltage Vout, so that the voltage difference follows the voltage difference between the first voltage reference Vr1 and the second voltage reference Vr2, thereby controlling the power consumption and heat dissipation of the linear current channel circuit 302A in the linear mode.

[0051] exist Figure 5 In this embodiment, the second differential adjustment circuit 502 receives the input voltage Vusb, the bus voltage Vbus, the third voltage reference Vr3, and the fourth voltage reference Vr4, and outputs a second linear control signal GL2 based on the input voltage Vusb, the bus voltage Vbus, the third voltage reference Vr3, and the fourth voltage reference Vr4. The second linear control signal GL2 represents an amplified error signal between the voltage difference between the input voltage Vusb and the bus voltage Vbus and the voltage difference between the third voltage reference Vr3 and the fourth voltage reference Vr4. The voltage difference amplifier controls the overvoltage protection power transistors MP1 and MP2 using the second linear control signal GL2, thereby controlling the voltage difference across the overvoltage protection circuit 301 (i.e., the difference between the input voltage Vusb and the bus voltage Vbus) to track the voltage difference between the third voltage reference Vr3 and the fourth voltage reference Vr4, thereby controlling the power consumption and heat dissipation of the overvoltage protection circuit 301 in the linear mode.

[0052] exist Figure 5In this embodiment, the third differential adjustment circuit 503 receives the bus voltage Vbus, the charge pump input voltage Vmbus, the fifth voltage reference Vr5, and the sixth voltage reference Vr6, and outputs a third linear control signal GL3 based on the bus voltage Vbus, the charge pump input voltage Vmbus, the fifth voltage reference Vr5, and the sixth voltage reference Vr6. The third linear control signal GL3 represents an amplified error signal between the voltage difference between the bus voltage Vbus and the charge pump input voltage Vmbus and the voltage difference between the fifth voltage reference Vr5 and the sixth voltage reference Vr6. The voltage difference amplifier uses the third linear control signal GL3 to control the anti-backflow power transistor MZ, thereby controlling the voltage difference across the anti-backflow circuit 307 (i.e., the difference between the bus voltage Vbus and the charge pump input voltage Vmbus) to track the voltage difference between the fifth voltage reference Vr5 and the sixth voltage reference Vr6, thereby controlling the power consumption and heat dissipation of the anti-backflow circuit 307 in the linear mode.

[0053] Figure 6 FIG. 6 is a schematic diagram of a module structure of a charging circuit 600 according to an embodiment of the present application. Figure 6 As shown, the charging circuit 600 includes an overvoltage protection circuit 301, a charge pump circuit 602, an anti-backflow circuit 307, a switch control circuit 603 and a linear control circuit 304. Figure 3 Compared with the embodiment, the structure of the charge pump circuit 602 is Figure 3 The charge pump circuit 302 is different from that in FIG. 3 , and accordingly, the control circuit of the charge pump circuit 602, namely the switch control circuit 603, is also different from that in FIG. 3 . Figure 3 The switch control circuit 303 in the embodiment is different.

[0054] Figure 6 The working principles of the overvoltage protection circuit 301 , the anti-backflow circuit 307 and the linear control circuit 304 in the embodiment have been introduced above and will not be elaborated here.

[0055] exist Figure 6 In this embodiment, the charge pump circuit 602 is a dual-phase charge pump circuit. Figure 3Compared to the embodiment, the charge pump circuit 602 includes two current paths, one of which is provided by the first phase circuit, which includes a first charge pump power transistor MA1, a second charge pump power transistor MB1, a third charge pump power transistor MC1, a fourth charge pump power transistor MD1, and a first flying capacitor Cf1. The other current path is provided by the second phase circuit, which includes a fifth charge pump power transistor MA2, a sixth charge pump power transistor MB2, a seventh charge pump power transistor MC2, an eighth charge pump power transistor MD2, and a second flying capacitor Cf2. The first and second phase circuits have the same structure and operate in the same principle, complementing each other in timing to reduce output voltage ripple. The operating principle of the single current path, namely, the charge pump circuit 302, has been described above, and the operating principle of the charge pump circuit 602 will not be further described here.

[0056] exist Figure 6 In the embodiment, the charge pump circuit 602 includes a linear current channel circuit 602A. The linear current channel circuit 602A includes a first charge pump power transistor MA1 and a second charge pump power transistor MB1 coupled between the charge pump input terminal T4 and the output voltage terminal T2, as well as a fifth charge pump power transistor MA2 and a sixth charge pump power transistor MB2 similarly coupled between the charge pump input terminal T4 and the output voltage terminal T2. In switching mode, all power transistors in the charge pump circuit 602, including the first charge pump power transistor MA1, the second charge pump power transistor MB1, the fifth charge pump power transistor MA2, and the sixth charge pump power transistor MB2, are turned on or off under the control of the charge pump control signal Vctr provided by the switch control circuit 603, thereby operating as a charge pump circuit. In the linear mode, the first linear control signal GL1 provided by the linear control circuit 304 controls the first charge pump power tube MA1, the second charge pump power tube MB1, the fifth charge pump power tube MA2 and the sixth charge pump power tube MB2 to operate in the linear region or the saturation region, and together with the overvoltage protection circuit 301 and the anti-backflow circuit 307 form a current channel to charge the battery 206.

[0057] Figure 7 FIG. 7 is a schematic diagram of a module structure of a charging circuit 700 according to an embodiment of the present application. Figure 7 As shown, the charging circuit 700 includes an overvoltage protection circuit 301, a charge pump circuit 702, an anti-backflow circuit 307, a switch control circuit 703 and a linear control circuit 304. Figure 3 Compared with the embodiment, the structure of the charge pump circuit 702 is Figure 3 The charge pump circuit 302 is different from that in FIG. 1 , and accordingly, the control circuit of the charge pump circuit 702, namely the switch control circuit 703, is also different from that in FIG. Figure 3 The switch control circuit 303 in the embodiment is different.

[0058] Figure 7The working principles of the overvoltage protection circuit 301 , the anti-backflow circuit 307 and the linear control circuit 304 in the embodiment have been introduced above and will not be elaborated here.

[0059] exist Figure 7 In one embodiment, the charge pump circuit 702 includes a first charge pump power transistor MA1, a second charge pump power transistor MB1, a third charge pump power transistor MC1, a fourth charge pump power transistor MD1, a fifth charge pump power transistor ME1, a sixth charge pump power transistor MF1, a seventh charge pump power transistor MG1, an eighth charge pump power transistor MH1, a first flying capacitor Cf1, a second flying capacitor Cf2, and a third flying capacitor Cf3. The first charge pump power transistor MA1, the second charge pump power transistor MB1, the third charge pump power transistor MC1, and the fourth charge pump power transistor MD1 are coupled in series between the charge pump input terminal T4 and the output voltage terminal T2. The fifth charge pump power transistor ME1 and the sixth charge pump power transistor MF1 are coupled in series between the output voltage terminal T2 and the ground terminal GND. The seventh charge pump power transistor MG1 and the eighth charge pump power transistor MH1 are coupled in series between the output voltage terminal T2 and the ground terminal GND. A first end of the first flying capacitor Cf1 is coupled to the connection point between the first charge pump power transistor MA1 and the second charge pump power transistor MB1, and a second end of the first flying capacitor Cf1 is coupled to the connection point between the fifth charge pump power transistor ME1 and the sixth charge pump power transistor MF1. A first end of the second flying capacitor Cf2 is coupled to the connection point between the third charge pump power transistor MC1 and the fourth charge pump power transistor MD1, and a second end of the second flying capacitor Cf2 is coupled to the connection point between the fifth charge pump power transistor ME1 and the sixth charge pump power transistor MF1. A first end of the third flying capacitor Cf3 is coupled to the connection point between the second charge pump power transistor MB1 and the third charge pump power transistor MC1, and a second end of the third flying capacitor Cf3 is coupled to the connection point between the seventh charge pump power transistor MG1 and the eighth charge pump power transistor MH1.

[0060] exist Figure 7 In this embodiment, the charge pump circuit 702 includes a linear current channel circuit 702A. The linear current channel circuit 702A includes power transistors coupled in series between the charge pump input terminal T4 and the output voltage terminal T2, namely, a first charge pump power transistor MA1, a second charge pump power transistor MB1, a third charge pump power transistor MC1, and a fourth charge pump power transistor MD1. When the linear current channel circuit 702A operates in a linear mode, the first charge pump power transistor MA1, the second charge pump power transistor MB1, the third charge pump power transistor MC1, and the fourth charge pump power transistor MD1 are turned on under the control of a first linear control signal GL1, and together with the overvoltage protection circuit 301 and the backflow prevention circuit 307, form a current channel to charge the battery 206.

[0061] In switching mode, all power transistors in charge pump circuit 702, including the first charge pump power transistor MA1, the second charge pump power transistor MB1, the third charge pump power transistor MC1, and the fourth charge pump power transistor MD1, are turned on or off under the control of the charge pump control signal Vctr provided by the switch control circuit 703, and operate as a charge pump circuit. Charge pump circuit 702 is a 4:1 charge pump circuit, and its operating principle is well known to those skilled in the art and will not be further described here.

[0062] Figure 8 FIG. 8 is a schematic diagram of a module structure of a charging circuit 800 according to an embodiment of the present application. Figure 8 As shown, the charging circuit 800 includes an overvoltage protection circuit 301, a charge pump circuit 802, an anti-backflow circuit 307, a switch control circuit 803 and a linear control circuit 304. Figure 7 Compared with the embodiment, the structure of the charge pump circuit 802 is Figure 7 The charge pump circuit 702 is different from that in FIG. 8 , and accordingly, the control circuit of the charge pump circuit 802, namely the switch control circuit 803, is also different from that in FIG. 8 . Figure 7 The switch control circuit 703 in the embodiment is different.

[0063] Figure 8 The working principles of the overvoltage protection circuit 301 , the anti-backflow circuit 307 and the linear control circuit 304 in the embodiment have been introduced above and will not be elaborated here.

[0064] exist Figure 8 In this embodiment, the charge pump circuit 802 is a dual-phase charge pump circuit. Figure 7 Compared to the embodiment, the charge pump circuit 802 includes two current paths. One current path consists of a first charge pump power transistor MA1, a second charge pump power transistor MB1, a third charge pump power transistor MC1, a fourth charge pump power transistor MD1, a fifth charge pump power transistor ME1, a sixth charge pump power transistor MF1, a seventh charge pump power transistor MG1, an eighth charge pump power transistor MH1, a first flying capacitor Cf1, a second flying capacitor Cf2, and a third flying capacitor Cf3. The other current path consists of a ninth charge pump power transistor MA3, a tenth charge pump power transistor MB3, an eleventh charge pump power transistor MC3, a twelfth charge pump power transistor MD3, a thirteenth charge pump power transistor ME3, a fourteenth charge pump power transistor MF3, a fifteenth charge pump power transistor MG3, a sixteenth charge pump power transistor MH3, a fourth flying capacitor Cf4, a fifth flying capacitor Cf5, and a sixth flying capacitor Cf6. The two current paths have the same structure and operate in the same principle, and are complementary in timing to reduce output voltage ripple.

[0065] exist Figure 8In the embodiment, the charge pump circuit 802 includes a linear current channel circuit 802A. The linear current channel circuit 802A includes a first charge pump power transistor MA1, a second charge pump power transistor MB1, a third charge pump power transistor MC1, and a fourth charge pump power transistor MD1, coupled between the charge pump input terminal T4 and the output voltage terminal T2. Furthermore, a ninth charge pump power transistor MA3, a tenth charge pump power transistor MB3, an eleventh charge pump power transistor MC3, and a twelfth charge pump power transistor MD3 are also coupled between the charge pump input terminal T4 and the output voltage terminal T2. In switching mode, all power transistors in the charge pump circuit 802, including the first charge pump power transistor MA1, the second charge pump power transistor MB1, the third charge pump power transistor MC1, the fourth charge pump power transistor MD1, the ninth charge pump power transistor MA3, the tenth charge pump power transistor MB3, the eleventh charge pump power transistor MC3, and the twelfth charge pump power transistor MD3, are turned on or off under the control of a charge pump control signal Vctr provided by the switch control circuit 803, thereby operating as a charge pump circuit. In the linear mode, the first linear control signal GL1 provided by the linear control circuit 304 controls the first charge pump power tube MA1, the second charge pump power tube MB1, the third charge pump power tube MC1, the fourth charge pump power tube MD1, the ninth charge pump power tube MA3, the tenth charge pump power tube MB3, the eleventh charge pump power tube MC3 and the twelfth charge pump power tube MD3 to operate in the linear region or the saturation region, and together with the overvoltage protection circuit 301 and the anti-backflow circuit 307 form a current channel to charge the battery 206.

[0066] In some embodiments of the present invention, the overvoltage protection circuit, the anti-backflow circuit and the linear current channel circuit in the charge pump circuit together constitute a current channel in a linear mode, drawing current from the input voltage end, i.e., the USB port, to the output voltage end to charge the battery or other loads. It should be understood that some applications do not have an overvoltage protection circuit and an anti-backflow circuit, or one of the two does not exist. In this case, the linear current channel circuit in the charge pump circuit itself can also constitute a current channel from the input voltage end to the output voltage end. In addition, the linear current channel circuit can also be combined with any one of the overvoltage protection circuit and the anti-backflow circuit to form a current channel. It should be understood that when the linear current channel circuit is coupled to the input voltage end and the output voltage end to form a current channel, the corresponding linear control circuit provides a first linear control signal for controlling the linear current channel circuit, then in Figure 4 In this embodiment, the second differential adjustment circuit 402 and the third differential adjustment circuit 403 can be omitted. Figure 5In this embodiment, the second differential adjustment circuit 502 and the third differential adjustment circuit 503 can be omitted. When the overvoltage protection circuit and the linear current channel circuit are coupled to the input voltage terminal and the output voltage terminal to form a current channel, the corresponding linear control circuit provides a first linear control signal and a second linear control signal for controlling the linear current channel circuit and the overvoltage protection circuit respectively. Figure 4 In this embodiment, the third differential adjustment circuit 403 can be omitted. Figure 5 In this embodiment, the third differential adjustment circuit 503 can be omitted. When the linear current channel circuit and the anti-backflow circuit are coupled to the input voltage terminal and the output voltage terminal to form a current channel, the corresponding linear control circuit provides a first linear control signal and a third linear control signal for controlling the linear current channel circuit and the anti-backflow circuit respectively. Figure 4 In this embodiment, the second differential adjustment circuit 402 can be omitted. Figure 5 In an embodiment, the second differential adjustment circuit 502 may be omitted.

[0067] In some embodiments, even if one or both of the overvoltage protection circuit and the backflow prevention circuit form a current channel with the linear current channel circuit, the overvoltage protection circuit and the backflow prevention circuit may not adopt an additional linear control method, that is, both can be in a straight-through state. Figure 4 In the embodiment, the second differential adjustment circuit 402 and the third differential adjustment circuit 403 are optional. Figure 5 In the embodiment, the second differential adjustment circuit 502 and the third differential adjustment circuit 503 are also optional.

[0068] Figure 9 FIG. 9 is a flow chart of a control method 900 for a charging circuit according to an embodiment of the present application. The charging circuit may be the aforementioned Figure 2 、 Figure 3 、 Figure 6 、 Figure 7 、 Figure 8 Any charging circuit in the embodiment. The control method 900 includes steps 901-903.

[0069] In step 901 , the operating mode of the charging circuit is determined. If the charging circuit operates in the switching mode, the process proceeds to step 902 . If the charging circuit operates in the linear mode, the process proceeds to step 903 .

[0070] When the input voltage terminal of the charging circuit is connected to the USB interface, the charger and the device where the battery is located (such as a mobile phone or tablet) shake hands through a specific communication protocol to determine whether the charging circuit should use linear mode or switch mode to charge the battery. In some embodiments, the operating mode of the charging circuit can be determined by judging the input voltage and / or input current of the input voltage terminal. It should be understood that the embodiments of the present application do not limit the method for determining the operating mode of the charging circuit, and any circuit or system that can be used to distinguish and set the operating mode of the charging circuit can be used in the embodiments of the present application.

[0071] In step 902, the charge pump circuit is controlled to operate in a switching mode;

[0072] In step 903 , the linear current channel circuit in the charge pump circuit is controlled to operate in a linear mode.

[0073] The linear current channel circuit includes a charge pump power transistor coupled between the charge pump input terminal and the output voltage terminal. In one embodiment, in a linear mode, the charge pump power transistor between the charge pump input terminal and the output voltage terminal operates in a linear region or a saturation region.

[0074] In one embodiment, in linear mode, a first linear control signal is provided based on the voltage difference between the charge pump input and output voltage terminals to control the charge pump power transistor in the linear current path circuit. In one embodiment, when the voltage difference between the charge pump input and output voltage terminals increases, the first linear control signal decreases, and the current in the linear current path circuit decreases accordingly. When the voltage difference between the charge pump input and output voltage terminals decreases, the first linear control signal increases, and the current in the linear current path circuit increases accordingly.

[0075] In one embodiment, an overvoltage protection circuit is included between the input voltage terminal and the charge pump input terminal, and the overvoltage protection circuit includes one or more overvoltage protection power tubes connected in series. In one embodiment, in linear mode, the one or more overvoltage protection power tubes connected in series are controlled based on a second linear control signal, and the second linear control signal is generated based on the voltage difference between the input terminal and the output terminal of the overvoltage protection circuit. In switching mode, the one or more overvoltage protection power tubes connected in series are controlled based on a first protection switch control signal. Normally, in switching mode, the one or more overvoltage protection power tubes connected in series remain fully conductive. In the event of overvoltage, the one or more overvoltage protection power tubes connected in series are turned off to protect the subsequent circuit.

[0076] In one embodiment, a backflow prevention circuit is further included between the overvoltage protection circuit and the charge pump circuit. The backflow prevention circuit includes at least one backflow prevention power transistor. In one embodiment, in linear mode, the at least one backflow prevention power transistor is controlled based on a third linear control signal, which is generated based on the voltage difference between the input and output terminals of the backflow prevention circuit. In switching mode, the at least one backflow prevention power transistor is controlled based on a second protection switch control signal. Typically, in switching mode, the at least one backflow prevention power transistor remains fully conductive. When reverse current is generated, the at least one backflow prevention power transistor is turned off.

[0077] In the embodiments of the present application, the charging circuit includes a charge pump circuit, or any combination of a charge pump circuit with an overvoltage protection circuit and / or an anti-backflow circuit. "Switching mode" indicates that the charging circuit operates in switching mode, meaning that the charge pump circuit, overvoltage protection circuit, and anti-backflow circuit in the charging circuit operate in switching mode. "Linear mode" indicates that the charging circuit operates in linear mode, meaning that the charge pump circuit, overvoltage protection circuit, anti-backflow circuit, and linear current channel circuit in the charge pump circuit operate in linear mode.

[0078] It should be understood that the logic circuits and the positive and negative input terminals of the corresponding comparators and error amplifiers in the embodiments of the present application are for illustrative purposes only. When the polarity of the signal is opposite, the polarity of the corresponding logic circuits and the input terminals may change.

[0079] It should be understood that in this application, "at least one (item)" means one or more, and "plurality" means two or more. "And / or" is used to describe the association relationship of associated objects, indicating that three relationships may exist. For example, "A and / or B" can mean: only A exists, only B exists, and A and B exist at the same time, where A and B can be singular or plural. The character " / " generally indicates that the previous and next associated objects are in an "or" relationship. "At least one of the following items" or similar expressions refers to any combination of these items, including any combination of single items or plural items. For example, at least one of a, b or c can mean: a, b, c, "a and b", "a and c", "b and c", or "a and b and c", where a, b, c can be single or multiple.

[0080] The above description is only a preferred embodiment of the present application and does not constitute any formal limitation to the present application. Although the present application has been disclosed as above with preferred embodiments, it is not intended to limit the present application. Any technician familiar with the art can use the above-disclosed methods and technical contents to make many possible changes and modifications to the technical solution of the present application without departing from the scope of the technical solution of the present application, or modify it into an equivalent embodiment with equivalent changes. Therefore, any simple modification, equivalent change and modification made to the above embodiments based on the technical essence of the present application without departing from the content of the technical solution of the present application still falls within the scope of protection of the technical solution of the present application.

Claims

1. A charging circuit comprising: a charge pump circuit having a first terminal, a second terminal, and a ground terminal, wherein the first terminal is coupled to the charge pump input terminal, the second terminal is coupled to the output voltage terminal, the charge pump input terminal receives a charge pump input voltage, the output voltage terminal provides an output voltage, and the charge pump circuit includes a linear current channel circuit; a linear control circuit providing a first linear control signal to the linear current channel circuit to enable the charge pump circuit to operate in a linear mode, wherein in the linear mode, the power transistors in the linear current channel circuit are turned on under the control of the first linear control signal, and the remaining power transistors in the charge pump circuit are turned off; The charge pump circuit further receives a charge pump control signal. When the charge pump circuit operates in a switching mode, the charge pump control signal controls the power tube in the charge pump circuit to be turned on or off.

2. The charging circuit according to claim 1, wherein the linear control circuit comprises: The first differential regulation circuit receives the charge pump input voltage and the output voltage, and outputs the first linear control signal based on the charge pump input voltage and the output voltage.

3. The charging circuit of claim 2 , wherein the first differential regulation circuit comprises: a first difference circuit receiving the charge pump input voltage and the output voltage, and outputting a first difference voltage based on the charge pump input voltage and the output voltage; as well as The first error amplifier circuit receives a first difference voltage reference and the first difference voltage, and outputs the first linear control signal based on the first difference voltage reference and the first difference voltage.

4. The charging circuit of claim 2 , wherein the first differential regulation circuit comprises: The first voltage difference comparison circuit receives the charge pump input voltage, the output voltage, a first voltage reference, and a second voltage reference, and outputs the first linear control signal based on the charge pump input voltage, the output voltage, the first voltage reference, and the second voltage reference.

5. The charging circuit according to claim 1 , further comprising: An overvoltage protection circuit has a first terminal, a second terminal and a control terminal, wherein the first terminal is coupled to the input voltage terminal, and the second terminal is coupled to the bus voltage terminal; The linear control circuit further provides a second linear control signal to the control terminal of the overvoltage protection circuit; in: When the charge pump circuit operates in a linear mode, the overvoltage protection circuit provides a current path from the input voltage terminal to the bus voltage terminal under the control of a second linear control signal; and When the charge pump circuit operates in the switching mode, the overvoltage protection circuit remains in the on state under the control of the first protection switch control signal.

6. The charging circuit according to claim 5, wherein the overvoltage protection circuit comprises: The overvoltage protection power tube has a source terminal, a drain terminal and a gate terminal, the drain terminal is coupled to the input voltage terminal, the source terminal is coupled to the bus voltage terminal, and the gate terminal receives the second linear control signal and the first protection switch control signal.

7. The charging circuit according to claim 5, wherein the overvoltage protection circuit comprises: A first overvoltage protection power tube has a source terminal, a drain terminal and a gate terminal, wherein the drain terminal is coupled to the input voltage terminal; as well as The second overvoltage protection power tube has a source terminal, a drain terminal and a gate terminal, the source terminal is coupled to the source terminal of the first overvoltage protection power tube, the drain terminal is coupled to the bus voltage terminal, and the gate terminal and the gate terminal of the first overvoltage protection power tube are coupled together to receive the second linear control signal and the first protection switch control signal.

8. The charging circuit according to claim 1, further comprising: An anti-backflow circuit has a first terminal, a second terminal and a control terminal, wherein the first terminal is coupled to the bus voltage terminal, and the second terminal is coupled to the charge pump input terminal; The linear control circuit further provides a third linear control signal to the control terminal of the anti-backflow circuit; in: When the charge pump circuit operates in a linear mode, the anti-backflow circuit provides a current path from the bus voltage terminal to the charge pump input terminal under the control of a third linear control signal; and When the charge pump circuit operates in the switching mode, the backflow prevention circuit remains in the on state under the control of the second protection switch control signal.

9. The charging circuit according to claim 8, wherein the backflow prevention circuit comprises: The anti-backflow power tube has a source terminal, a drain terminal and a gate terminal, the source terminal is coupled to the bus voltage terminal, the drain terminal is coupled to the charge pump input terminal, and the gate terminal receives the third linear control signal and the second protection switch control signal.

10. The charging circuit according to claim 1, further comprising: An overvoltage protection circuit has a first terminal, a second terminal and a control terminal, wherein the first terminal is coupled to the input voltage terminal, and the second terminal is coupled to the bus voltage terminal; as well as An anti-backflow circuit has a first terminal, a second terminal and a control terminal, wherein the first terminal is coupled to the bus voltage terminal, and the second terminal is coupled to the charge pump input terminal; The linear control circuit further provides a second linear control signal to the control terminal of the overvoltage protection circuit, and provides a third linear control signal to the control terminal of the anti-backflow circuit; in: When the charge pump circuit operates in a linear mode, the overvoltage protection circuit provides a current path from the input voltage terminal to the bus voltage terminal under the control of the second linear control signal, and the backflow prevention circuit provides a current path from the bus voltage terminal to the charge pump input terminal under the control of the third linear control signal; as well as When the charge pump circuit operates in the switching mode, the overvoltage protection circuit remains in the on state under the control of the first protection switch control signal, and the backflow prevention circuit remains in the on state under the control of the second protection switch control signal.

11. The charging circuit of claim 10 , wherein the linear control circuit comprises: a first differential regulation circuit receiving the charge pump input voltage and the output voltage, and outputting the first linear control signal based on the charge pump input voltage and the output voltage; a second differential regulation circuit receiving the input voltage and the bus voltage, and outputting the second linear control signal based on the input voltage and the bus voltage; as well as The third differential regulation circuit receives the bus voltage and the charge pump input voltage, and outputs the third linear control signal based on the bus voltage and the charge pump input voltage.

12. The charging circuit of claim 11, wherein: The first differential adjustment circuit includes: a first difference circuit receiving the charge pump input voltage and the output voltage, and outputting a first difference voltage based on the charge pump input voltage and the output voltage; and a first error amplifier circuit receiving a first difference voltage reference and the first difference voltage, and outputting the first linear control signal based on the first difference voltage reference and the first difference voltage; The second differential adjustment circuit includes: a second difference circuit receiving the input voltage and the bus voltage and outputting a second difference voltage based on the input voltage and the bus voltage; and a second error amplifier circuit receiving a second difference voltage reference and the second difference voltage, and outputting the second linear control signal based on the second difference voltage reference and the second difference voltage; The third differential adjustment circuit includes: a third difference circuit receiving the bus voltage and the charge pump input voltage and outputting a third difference voltage based on the bus voltage and the charge pump input voltage; and The third error amplifier circuit receives a third difference voltage reference and the third difference voltage, and outputs the third linear control signal based on the third difference voltage reference and the third difference voltage.

13. The charging circuit of claim 11, wherein: The first differential adjustment circuit includes: a first voltage difference comparison circuit receiving the charge pump input voltage, the output voltage, a first voltage reference, and a second voltage reference, and outputting the first linear control signal based on the charge pump input voltage, the output voltage, the first voltage reference, and the second voltage reference; The second differential adjustment circuit includes: a second voltage difference comparison circuit receiving the input voltage, the bus voltage, a third voltage reference, and a fourth voltage reference, and outputting the second linear control signal based on the input voltage, the bus voltage, the third voltage reference, and the fourth voltage reference; The third differential adjustment circuit includes: The third voltage difference comparison circuit receives the bus voltage, the charge pump input voltage, the fifth voltage reference and the sixth voltage reference, and outputs the third linear control signal based on the bus voltage, the charge pump input voltage, the fifth voltage reference and the sixth voltage reference.

14. The charging circuit of claim 1 , wherein the charge pump circuit comprises: A first charge pump power tube; A second charge pump power tube; A third charge pump power tube; a fourth charge pump power tube; as well as First Flying Capacitor; Wherein, the first charge pump power tube, the second charge pump power tube, the third charge pump power tube and the fourth charge pump power tube are coupled in series between the first end of the charge pump circuit and the ground end, the first end of the first flying capacitor is coupled to the connection point of the first charge pump power tube and the second charge pump power tube, the second end of the first flying capacitor is coupled to the connection point of the third charge pump power tube and the fourth charge pump power tube, and the connection point of the second charge pump power tube and the third charge pump power tube is coupled to the output voltage end; The linear current channel circuit includes the first charge pump power tube and the second charge pump power tube.

15. The charging circuit of claim 1 , wherein the charge pump circuit comprises: A first charge pump power tube; A second charge pump power tube; A third charge pump power tube; a fourth charge pump power tube; fifth charge pump power tube; a sixth charge pump power tube; seventh charge pump power tube; an eighth charge pump power tube; First Flying Capacitor; as well as Second flying capacitor; Wherein, the first charge pump power tube, the second charge pump power tube, the third charge pump power tube and the fourth charge pump power tube are coupled in series between the first end of the charge pump circuit and the ground end, the first end of the first flying capacitor is coupled to the connection point of the first charge pump power tube and the second charge pump power tube, the second end of the first flying capacitor is coupled to the connection point of the third charge pump power tube and the fourth charge pump power tube, and the connection point of the second charge pump power tube and the third charge pump power tube is coupled to the output voltage end; wherein the fifth charge pump power tube, the sixth charge pump power tube, the seventh charge pump power tube, and the eighth charge pump power tube are coupled in series between the first end of the charge pump circuit and the ground end; the first end of the second flying capacitor is coupled to the connection point between the fifth charge pump power tube and the sixth charge pump power tube; the second end of the second flying capacitor is coupled to the connection point between the seventh charge pump power tube and the eighth charge pump power tube; and the connection point between the sixth charge pump power tube and the seventh charge pump power tube is coupled to the output voltage end; and The linear current channel circuit includes the first charge pump power tube, the second charge pump power tube, the fifth charge pump power tube and the sixth charge pump power tube.

16. The charging circuit of claim 1 , wherein the charge pump circuit comprises: A first charge pump power tube; A second charge pump power tube; A third charge pump power tube; a fourth charge pump power tube; fifth charge pump power tube; a sixth charge pump power tube; seventh charge pump power tube; an eighth charge pump power tube; First Flying Capacitor; Second flying capacitor; as well as The third flying capacitor; Wherein, the first, second, third and fourth charge pump power tubes are coupled in series between the first terminal of the charge pump circuit and the output voltage terminal, the fifth and sixth charge pump power tubes are coupled in series between the output voltage terminal and the ground terminal, and the seventh and eighth charge pump power tubes are coupled in series between the output voltage terminal and the ground terminal. A first end of the first flying capacitor is coupled to a connection point between the first and second charge pump power tubes, a second end of the first flying capacitor is coupled to a connection point between the fifth and sixth charge pump power tubes, a first end of the second flying capacitor is coupled to a connection point between the third and fourth charge pump power tubes, a second end of the second flying capacitor is coupled to a connection point between the fifth and sixth charge pump power tubes, a first end of the third flying capacitor is coupled to a connection point between the second and third charge pump power tubes, and a second end of the third flying capacitor is coupled to a connection point between the seventh and eighth charge pump power tubes. The linear current channel circuit includes the first charge pump power tube, the second charge pump power tube, the third charge pump power tube and the fourth charge pump power tube.

17. The charging circuit of claim 1 , wherein the charge pump circuit comprises: A first charge pump power tube; A second charge pump power tube; A third charge pump power tube; a fourth charge pump power tube; fifth charge pump power tube; a sixth charge pump power tube; seventh charge pump power tube; an eighth charge pump power tube; ninth charge pump power tube; tenth charge pump power tube; 11th charge pump power tube; 12th charge pump power tube; 13th charge pump power tube; Fourteenth charge pump power tube; Fifteenth charge pump power tube; Sixteenth charge pump power tube; First Flying Capacitor; Second flying capacitor; The third flying capacitor; Fourth flying capacitor; Fifth Flying Capacitor; Sixth Flying Capacitor; Wherein, the first, second, third and fourth charge pump power tubes are coupled in series between a first terminal of the charge pump circuit and an output voltage terminal, the fifth and sixth charge pump power tubes are coupled in series between the output voltage terminal and a ground terminal, and the seventh and eighth charge pump power tubes are coupled in series between the output voltage terminal and a ground terminal. A first end of the first flying capacitor is coupled to a connection point between the first and second charge pump power tubes, a second end of the first flying capacitor is coupled to a connection point between the fifth and sixth charge pump power tubes, a first end of the second flying capacitor is coupled to a connection point between the third and fourth charge pump power tubes, a second end of the second flying capacitor is coupled to a connection point between the fifth and sixth charge pump power tubes, a first end of the third flying capacitor is coupled to a connection point between the second and third charge pump power tubes, and a second end of the third flying capacitor is coupled to a connection point between the seventh and eighth charge pump power tubes. Among them, the ninth charge pump power tube, the tenth charge pump power tube, the eleventh charge pump power tube and the twelfth charge pump power tube are coupled in series between the first end and the output voltage end of the charge pump circuit, the thirteenth charge pump power tube and the fourteenth charge pump power tube are coupled in series between the output voltage end and the ground end, the fifteenth charge pump power tube and the sixteenth charge pump power tube are coupled in series between the output voltage end and the ground end, the first end of the fourth flying capacitor is coupled to the connection point of the ninth charge pump power tube and the tenth charge pump power tube, and the second end of the fourth flying capacitor is coupled to the connection point of the ninth charge pump power tube and the tenth charge pump power tube. coupled to a connection point between the thirteenth charge pump power tube and the fourteenth charge pump power tube, a first end of the fifth flying capacitor is coupled to a connection point between the eleventh charge pump power tube and the twelfth charge pump power tube, a second end of the fifth flying capacitor is coupled to a connection point between the thirteenth charge pump power tube and the fourteenth charge pump power tube, a first end of the sixth flying capacitor is coupled to a connection point between the tenth charge pump power tube and the eleventh charge pump power tube, and a second end of the sixth flying capacitor is coupled to a connection point between the fifteenth charge pump power tube and the sixteenth charge pump power tube; The linear current channel circuit includes the first charge pump power tube, the second charge pump power tube, the third charge pump power tube, the fourth charge pump power tube, the ninth charge pump power tube, the tenth charge pump power tube, the eleventh charge pump power tube and the twelfth charge pump power tube.

18. A method for controlling a charging circuit, the charging circuit comprising a charge pump circuit, the charge pump circuit comprising a charge pump power transistor, the control method comprising: Determine the operating mode of the charging circuit, where: If the charging circuit operates in a switching mode, controlling the charge pump circuit to operate in the switching mode; and If the charging circuit operates in the linear mode, the linear current channel circuit in the charge pump circuit is controlled to operate in the linear mode, wherein the linear current channel circuit includes a charge pump power tube coupled between the charge pump input terminal and the output voltage terminal.

19. The control method of the charging circuit as claimed in claim 18, wherein controlling the linear current channel circuit in the charge pump circuit to operate in a linear mode comprises: A first linear control signal is provided based on a voltage difference between an input terminal and an output voltage terminal of the charge pump to control a charge pump power tube in a linear current channel circuit.

20. The control method of a charging circuit according to claim 18, wherein an overvoltage protection circuit is provided between an input voltage terminal and a bus voltage terminal of the charging circuit, the overvoltage protection circuit comprising one or more overvoltage protection power transistors connected in series, the control method further comprising: In the linear mode, the one or more overvoltage protection power transistors connected in series are controlled based on a second linear control signal, wherein the second linear control signal is generated based on a voltage difference between an input terminal and an output terminal of the overvoltage protection circuit; as well as In the switch mode, the one or more overvoltage protection power transistors connected in series are controlled based on a first protection switch control signal.

21. The control method of a charging circuit according to claim 18, wherein a backflow prevention circuit is provided between a bus voltage terminal and a charge pump input terminal of the charging circuit, the backflow prevention circuit including at least one backflow prevention power transistor, the control method further comprising: In the linear mode, the at least one anti-backflow power transistor is controlled based on a third linear control signal, wherein the third linear control signal is generated based on a voltage difference between an input terminal and an output terminal of the anti-backflow circuit; as well as In the switch mode, the at least one backflow prevention power tube is controlled based on the second protection switch control signal.

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