CN220107627U

CN220107627U - Charging protection circuit, charging circuit and electronic equipment

Info

Publication number: CN220107627U
Application number: CN202321571007.XU
Authority: CN
Inventors: 魏琦昆; 王冠杰; 李嘉健
Original assignee: Beijing Xiaomi Mobile Software Co Ltd
Current assignee: Beijing Xiaomi Mobile Software Co Ltd
Priority date: 2023-06-19
Filing date: 2023-06-19
Publication date: 2023-11-28
Anticipated expiration: 2033-06-19

Abstract

The present disclosure relates to a charge protection circuit, a charge circuit and an electronic device, the charge protection circuit includes: the first overvoltage protection unit comprises a switch unit and a backflow prevention unit, wherein the first end of the switch unit is used for being coupled with the first end of the charging management circuit, the second end of the switch unit is used for being coupled with the charging port, and the third end of the switch unit is used for being coupled with the second end of the charging management circuit; the first end of the burn-proof unit is used for being coupled with the grounding end, the second end of the burn-proof unit is coupled with the second end of the switch unit, and the third end of the burn-proof unit is used for being coupled with the third end of the charge management circuit; the anti-backflow unit is coupled between the first end of the charging management circuit and the second end of the anti-burning unit and is used for preventing current of the charging management circuit from flowing into the grounding end through the anti-burning unit; the charging management circuit is used for controlling the working states of the switch unit and the burn-proof unit. The backflow of current is prevented through the backflow preventing unit, damage to the charging management circuit is avoided, and damage to electronic equipment is prevented.

Description

Charging protection circuit, charging circuit and electronic equipment

Technical Field

The disclosure relates to the field of charging technologies, and in particular relates to a charging protection circuit, a charging circuit and electronic equipment.

Background

At present, in the process of charging electronic equipment, the problem of short circuit possibly occurs under the influence of a charging environment, and the electronic equipment needs to be protected by adopting a charging protection circuit. However, during the operation of the charging protection circuit, the circuit may be burned out, resulting in damage to the electronic device.

Disclosure of Invention

In order to overcome the problems in the related art, the present disclosure provides a charging protection circuit, a charging circuit, and an electronic device.

According to a first aspect of the present disclosure, there is provided a charge protection circuit including:

the first overvoltage protection unit comprises a switch unit and a backflow prevention unit, wherein a first end of the switch unit is used for being coupled with a first end of the charging management circuit, a second end of the switch unit is used for being coupled with a charging port, and a third end of the switch unit is used for being coupled with a second end of the charging management circuit;

the first end of the burn-proof unit is used for being coupled with the grounding end, the second end of the burn-proof unit is coupled with the second end of the switch unit, and the third end of the burn-proof unit is used for being coupled with the third end of the charge management circuit;

The anti-backflow unit is coupled between the first end of the charge management circuit and the second end of the anti-burning unit, and is used for preventing current of the charge management circuit from flowing into the grounding end through the anti-burning unit; the charging management circuit is used for controlling the working states of the switch unit and the burn-proof unit.

In some embodiments of the present disclosure, the switching unit includes a first switching tube and a second switching tube, a first end of the first switching tube is coupled with a first end of the second switching tube, a second end of the first switching tube is coupled with the charging port, a second end of the second switching tube is coupled with a first end of the charging management circuit, and third ends of the first switching tube and the second switching tube are both coupled with a second end of the charging management circuit; the first switch tube is coupled with a first unidirectional device in parallel, the backflow prevention unit comprises a second unidirectional device, and the arrangement directions of the first unidirectional device and the second unidirectional device are opposite.

In some embodiments of the present disclosure, the first switching tube is a field effect tube, and a body diode of the first switching tube forms the first unidirectional device; and/or the second switching tube is a field effect tube, and the body diode of the second switching tube forms the second unidirectional device.

In some embodiments of the present disclosure, the burn-out prevention unit includes:

and the first end of the third switching tube is coupled with the grounding end, the second end of the third switching tube is coupled with the second end of the switching unit, and the third end of the third switching tube is coupled with the third end of the charging management circuit.

In some embodiments of the present disclosure, the charge management circuit includes a charge pump and a power management circuit, a first end of the charge pump is a first end of the charge management circuit, a second end of the charge pump is a second end of the charge management circuit, and a first end of the power management circuit is a third end of the charge management circuit.

In some embodiments of the present disclosure, the charge management circuit further comprises a processor; the charge protection circuit further includes:

and the first end of the second overvoltage protection unit is used for being coupled with the second end of the power management circuit, the second end of the second overvoltage protection unit is coupled with the first end of the switch unit, and the third end of the second overvoltage protection unit is used for being coupled with the first end of the processor.

In some embodiments of the disclosure, the second overvoltage protection unit includes a fourth switching tube and a fifth switching tube, a first end of the fourth switching tube is coupled to a first end of the fifth switching tube, a second end of the fourth switching tube is coupled to a first end of the switching unit, a second end of the fifth switching tube is coupled to a second end of the power management circuit, and third ends of the fourth switching tube and the fifth switching tube are both coupled to a first end of the processor; the third unidirectional device is connected in parallel with the fourth switching tube, the fourth unidirectional device is connected in parallel with the fifth switching tube, and the setting directions of the third unidirectional device and the fourth unidirectional device are opposite.

In some embodiments of the present disclosure, the charge protection circuit further includes:

the first end of the voltage detection unit is coupled with the second end of the switch unit and the second end of the burn-proof unit, the second end of the voltage detection unit is used for being coupled with the grounding end, the third end of the voltage detection unit is used for being coupled with the fourth end of the charging management circuit, and the charging management circuit detects the voltage of the charging port through the voltage detection unit.

In some embodiments of the present disclosure, the voltage detection unit includes:

the first end of the fixed resistor is coupled with the second end of the switch unit and the second end of the burn-proof unit;

and the first end of the thermistor is used as the third end of the voltage detection unit and is coupled with the second end of the fixed resistor, and the second end of the thermistor is coupled with the grounding end.

the first end of the control unit is used for being coupled with the second end of the charging management circuit, the second end of the control unit is used for being coupled with the third end of the charging management circuit, the third end of the control unit is coupled with the third end of the burn-out prevention unit, and the charging management circuit controls the working state of the burn-out prevention unit through the control unit.

In some embodiments of the present disclosure, the control unit includes:

and the first end of the AND logic gate is coupled with the third end of the switch unit, the second end of the AND logic gate is coupled with the third end of the charge management circuit, and the third end of the AND logic gate is coupled with the third end of the burn-out prevention unit.

According to a second aspect of the present disclosure, there is provided a charging circuit comprising a charging management circuit and a charging protection circuit as described above, the charging protection circuit being coupled with the charging management circuit.

In some embodiments of the present disclosure, the charge management circuit includes a charge pump and a power management circuit, the charge protection circuit being coupled to both the charge pump and the power management circuit.

According to a third aspect of the present disclosure, there is provided an electronic device comprising a charging circuit as described above.

The technical scheme provided by the embodiment of the disclosure can comprise the following beneficial effects:

because the anti-backflow unit in the first overvoltage protection unit is coupled between the charging management circuit and the anti-burning unit, when the charging protection circuit performs anti-burning protection through the anti-burning unit, the residual charging voltage in the charging management circuit cannot flow into the grounding end through the anti-backflow unit and the anti-burning unit. The backflow of current is prevented through the backflow preventing unit, damage to the charging management circuit is avoided, and damage to electronic equipment is prevented.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the disclosure.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the invention and together with the description, serve to explain the principles of the invention.

FIG. 1 is a schematic diagram of a charging circuit;

fig. 2 is a schematic structural view of a charging apparatus;

fig. 3 is a schematic diagram of a charging protection circuit according to an exemplary embodiment of the present disclosure;

fig. 4-1 is a schematic diagram of a charge protection circuit provided in another exemplary embodiment of the present disclosure;

fig. 4-2 is a schematic diagram of a charging protection circuit provided in another exemplary embodiment of the present disclosure;

fig. 5 is a schematic diagram of a charging protection circuit provided in another exemplary embodiment of the present disclosure;

fig. 6 is a schematic diagram of a charging protection circuit provided in another exemplary embodiment of the present disclosure;

fig. 7 is a schematic diagram of a charging protection circuit provided in another exemplary embodiment of the present disclosure;

fig. 8 is a schematic diagram of a charging protection circuit provided in another exemplary embodiment of the present disclosure;

fig. 9 is a schematic diagram of a charging protection circuit provided in another exemplary embodiment of the present disclosure;

fig. 10 is a schematic diagram of a charge protection circuit provided in another exemplary embodiment of the present disclosure;

Fig. 11 is a schematic structural view of a charge protection circuit provided in another exemplary embodiment of the present disclosure;

fig. 12 is a schematic diagram of a charging protection circuit provided in another exemplary embodiment of the present disclosure;

fig. 13 is a timing diagram of signals of a charge protection circuit provided by an exemplary embodiment of the present disclosure;

fig. 14 is a system block diagram of an electronic device provided by an exemplary embodiment of the present disclosure.

In the figure:

10-a charge protection circuit; 11-a first overvoltage protection unit; 12-a burn-proof unit; 13-a second overvoltage protection unit; 14-a voltage detection unit; 15-a control unit; 20-a charge management circuit; 21-a charge pump; 22-a power management circuit; 30-a charging device; 31-a power transformation circuit; 40-interface; 50-terminal; 51-a low-voltage direct-charging control chip; 52-cell; a 111-switch unit; 112-a backflow prevention unit; 400-an electronic device; 402-a processing component; 404-memory; 406-a power supply assembly; 408-a multimedia component; 410-an audio component; 412-an input-output interface; 414-sensor assembly; 416-a communication component; 420-a processor; q1-a first switching tube; q2-a second switching tube; q3-a third switching tube; q4-fourth switching tube; q5-a fifth switching tube; VD 1-a first unidirectional device; VD 2-a second unidirectional device; VD 3-a third unidirectional device; VD 4-fourth unidirectional device; r1 is a fixed resistor; r2-thermistor; AND-AND logic gates; vbus-charging port; VCC-power supply; GND-ground; vin-input; AGND-common; a Vsen-voltage sense terminal; an OVP-overvoltage protection end; c1-a first control end; a C2-second control terminal; a C3-third control terminal; en-Enable; gate-burn-proof end; an ID-regulatory end; d+ -a first data terminal; d-the second data terminal.

Detailed Description

Reference will now be made in detail to exemplary embodiments, examples of which are illustrated in the accompanying drawings. When the following description refers to the accompanying drawings, the same numbers in different drawings refer to the same or similar elements, unless otherwise indicated. The implementations described in the following exemplary examples do not represent all implementations consistent with the invention. Rather, they are merely examples of apparatus and methods consistent with aspects of the invention as detailed in the accompanying claims.

At present, in the process of charging electronic equipment, the problem of short circuit possibly occurs under the influence of a charging environment, and the electronic equipment needs to be protected by adopting a charging protection circuit. For example, when the electronic device is charged through the data line, if foreign matters or liquid enter the interface (such as Type-C interface) of the electronic device to cause a short circuit between the input end and the ground end of the interface, a large current flows through the interface and abnormal heat is generated. Or when the electronic equipment is charged through the data line, the interface of the electronic equipment is close to the high-temperature heat source, and the circuit or the device in the electronic equipment is easy to damage and short-circuit occurs. When the short circuit problem occurs, a charging protection circuit in the electronic equipment acts to protect the circuit in the electronic equipment.

As shown in fig. 1, the charging circuit of the electronic device includes a charge protection circuit 10, a charge pump 21, a power management circuit 22, and a processor 420. The charge protection circuit 10 includes a first switching tube Q1, a second switching tube Q2, a third switching tube Q3, a fixed resistor R1, and a thermistor R2. The first terminal of the fixed resistor R1 is coupled to the charging port Vbus, and the second terminal is coupled to both the first terminal of the thermistor R2 and the voltage detection terminal Vsen in the power management circuit 22. The second terminal of the thermistor R2 is coupled to the ground GND. The first switch tube Q1 has a first end coupled to the input Vin of the charge pump 21, a second end coupled to the charging port Vbus and a first end of the fixed resistor R1, and a control end coupled to the overvoltage protection terminal OVP of the charge pump 21. The first end of the second switching tube Q2 is coupled to the input end Vin of the power management circuit 22, the second end is coupled to both the first end of the first switching tube Q1 and the input end Vin of the charge pump 21, and the control end is coupled to the first control end C1 of the processor 420. The first switching tube Q1 is connected with a first unidirectional device VD1 in parallel, and the second switching tube Q2 is connected with a second unidirectional device VD2 in parallel. The first end of the third switching tube Q3 is coupled to the ground GND, the second end is coupled to the charging port Vbus, the first end of the fixed resistor R1 and the second end of the first switching tube Q1, and the control end is coupled to the burn-proof end Gate of the power management circuit 22. The common terminal AGND of the charge pump 21, the power management circuit 22 and the processor 420 is coupled to the ground terminal GND. The input terminal Vin of the processor 420 is coupled to the power supply VCC, the second control terminal C2 is coupled to the enable terminal En of the charge pump 21, and the third control terminal C3 is coupled to the enable terminal En of the power management circuit 22. The voltage outputs of the charge pump 21 and the power management circuit 22 are coupled to a battery (not shown).

When the battery is charged rapidly, the processor 420 controls the charge pump 21 to charge the battery and controls the second switching tube Q2 to be turned off. When the battery is charged normally, the processor 420 controls the power management circuit 22 to charge the battery and controls the second switching tube Q2 to be turned on. When a short circuit problem occurs, the voltage of the first end of the thermistor R2 received by the power management circuit 22 decreases, and the third switching tube Q3 is turned on through the burn-out preventing end Gate. The voltage input to the charge pump 21 is lower than the undervoltage threshold due to the conduction of the third switching tube Q3, and the charge pump 21 turns off the first switching tube Q1, thereby achieving short-circuit protection. The undervoltage threshold may be, for example, a value between 2V and 4V. However, in the charge protection circuit 10, during the protection process, the charge voltage remaining in the charge pump 21 forms a current flowing backward to the ground GND through the first unidirectional device VD1 and the third switching tube Q3 connected in parallel to the first switching tube Q1, resulting in damage to the charge pump 21 and the power management circuit 22. Meanwhile, the remaining charging voltage in the power management circuit 22 may form a current flowing backward to the ground GND through the first unidirectional device VD1, the second unidirectional device VD2 and the third switching transistor Q3, resulting in damage to the charge pump 21 and the power management circuit 22.

In the related art, a charging apparatus is disclosed, and as shown in fig. 2, the charging apparatus 30 is coupled with a terminal 50 through an interface 40. The charging device 30 includes a first switching tube Q1, a second switching tube Q2, and a power transformation circuit 31. The first ends of the first switching tube Q1 and the second switching tube Q2 are coupled to each other, and the second end of the first switching tube Q1 is coupled to the power transformation circuit 31. A second terminal of the second switching transistor Q2 is coupled to the input Vin of the interface 40. The control terminals of the first switching tube Q1 and the second switching tube Q2 are coupled to the regulation terminal ID of the interface 40. The first switching tube Q1 is connected in parallel with a first unidirectional device VD1, the second switching tube Q2 is connected in parallel with a second unidirectional device VD2, and the setting directions of the first unidirectional device VD1 and the second unidirectional device VD2 are opposite. The charging device 30 is further coupled to both the first data terminal d+, the second data terminal D-and the common terminal AGND of the interface 40. The common terminal AGND of the interface 40 is coupled to the ground terminal GND in the terminal 50. The terminal 50 includes a low-voltage direct-charge charging control chip 51 and a battery 52. The low-voltage direct-charge control chip 51 is coupled to the first data terminal d+, the second data terminal D-and the regulation terminal ID of the interface 40. The battery 52 is coupled to the input Vin of the interface 40. Although the charging device 30 can prevent the current in the battery 52 from flowing backward to the power transformation circuit 31 when the charging is abnormal, the devices in the charging device 30 and the low-voltage direct-charging control chip 51 cannot be protected when short-circuited, and there is still a possibility that the charging device and the electronic device are burned out. Meanwhile, the charging device 30 cannot be applied to the case involving the quick charge and the ordinary charge.

Based on this, the present disclosure provides a charge protection circuit that charge protects a charge management circuit through a backflow prevention unit and a burn prevention unit in a first overvoltage protection unit. In the process of charging protection, residual charging voltage in the charging management circuit cannot flow into the grounding end through the current formed by the backflow prevention unit and the burning prevention unit, so that the backflow of the current is prevented to avoid damage to the charging management circuit. Meanwhile, the anti-burning unit can protect the charge management circuit when the short circuit problem occurs, and the charge management circuit is prevented from being damaged.

As shown in fig. 3, an exemplary embodiment of the present disclosure provides a charge protection circuit 10 including a first overvoltage protection unit 11 and a burn-out prevention unit 12. The first overvoltage protection unit 11 includes a switching unit 111 and a backflow prevention unit 112. The first terminal of the switching unit 111 is coupled to the first terminal of the charge management circuit 20, the second terminal is coupled to the charge port Vbus, and the third terminal is coupled to the second terminal of the charge management circuit 20. The burn-out prevention unit 12 has a first terminal coupled to the ground GND, a second terminal coupled to the second terminal of the switch unit 111, and a third terminal coupled to a third terminal of the charge management circuit 20. The anti-backflow unit 112 is coupled between the first end of the charge management circuit 20 and the second end of the burn-out preventing unit 12, and is used for preventing the current of the charge management circuit 20 from flowing into the ground GND through the burn-out preventing unit 12. The charge management circuit 20 is used for controlling the operating states of the switching unit 111 and the burn-out prevention unit 12. The first terminal of the charge management circuit 20 may be, for example, an input terminal Vin of the charge management circuit 20, the second terminal of the charge management circuit 20 may be, for example, an overvoltage protection terminal OVP of the charge management circuit 20, and the third terminal of the charge management circuit 20 may be, for example, an anti-burn terminal Gate of the charge management circuit 20.

The first overvoltage protection unit 11 can be used for overvoltage protection on the one hand and can be used for short-circuit protection in conjunction with the burn-out protection unit 12 on the other hand. When a short circuit problem occurs, the burn-out prevention unit 12 is controlled by the charge management circuit 20 to be turned on, and the voltage of the first end of the charge management circuit 20 is lower than the under-voltage threshold. At this time, the charge management circuit 20 turns off the switching unit 111, thereby realizing short-circuit protection. If the charging voltage remains in the charging management circuit 20, the backflow prevention unit 112 can prevent the charging voltage remaining in the charging management circuit 20 from forming a current, and thus prevent the current from flowing backward.

In this embodiment, since the anti-backflow unit in the first overvoltage protection unit is coupled between the charge management circuit and the anti-burn unit, when the charge protection circuit performs anti-burn protection through the anti-burn unit, the residual charge voltage in the charge management circuit cannot flow into the ground terminal through the anti-backflow unit and the anti-burn unit. The backflow of current is prevented through the backflow preventing unit, damage to the charging management circuit is avoided, and damage to electronic equipment is prevented.

In one embodiment, as shown in fig. 4-1 and 4-2, the switching unit 111 includes a first switching tube Q1 and a second switching tube Q2. The first end of the first switching tube Q1 is coupled to the first end of the second switching tube Q2, and the second end of the first switching tube Q1 is coupled to the charging port Vbus. A second terminal of the second switching tube Q2 is coupled to a first terminal of the charge management circuit 20. Third terminals of the first switching tube Q1 and the second switching tube Q2 are coupled to a second terminal of the charge management circuit 20. When the first switching tube Q1 and the second switching tube Q2 are N-type switching tubes, the first switching tube Q1 is coupled in parallel with the first unidirectional device VD1. The backflow preventing unit 112 includes a second unidirectional device VD2. The second unidirectional device VD2 is coupled in parallel with the second switching tube Q2, and the first unidirectional device VD1 and the second unidirectional device VD2 are disposed in opposite directions. When the first switching tube Q1 and the second switching tube Q2 are P-type switching tubes, the second switching tube Q2 is coupled in parallel with the second unidirectional device VD2. The backflow preventing unit 112 includes a first unidirectional device VD1. The first unidirectional device VD1 is coupled in parallel with the first switching tube Q1, and the first unidirectional device VD1 and the second unidirectional device VD2 are disposed in opposite directions.

In this embodiment, since the first unidirectional device and the second unidirectional device are disposed in opposite directions, the charging voltage remaining in the charging management circuit cannot flow into the ground terminal through the first unidirectional device, the second unidirectional device and the burn-out preventing unit, so that the current is prevented from flowing backward.

In one embodiment, the first switching tube Q1 is a field effect tube, and the body diode of the first switching tube Q1 forms a first unidirectional device VD1.

In this embodiment, when the first switching tube is a field effect tube, the body diode of the first switching tube forms a first unidirectional device, and freewheeling can be realized without connecting the freewheeling diode in parallel, thereby reducing the complexity of the structure of the charging protection circuit. The body diode of the first switching tube is parasitic on the first switching tube and cannot be separated, and the current is prevented from flowing backwards through the second unidirectional device, so that the damage of the charge management circuit is avoided.

In one embodiment, the second switching tube Q2 is a field effect tube, and the body diode of the second switching tube Q2 forms a second unidirectional device VD2.

In this embodiment, when the second switching tube is a field effect tube, the body diode of the second switching tube forms a second unidirectional device, and freewheeling can be realized without connecting the freewheeling diode in parallel, thereby reducing the complexity of the charging protection circuit structure. The body diode of the second switching tube is parasitic on the second switching tube and cannot be separated, and the current is prevented from flowing backwards through the first unidirectional device, so that the damage of the charge management circuit is avoided.

It is understood that the first switching transistor Q1 and the second switching transistor Q2 may be transistors such as insulated gate bipolar transistors, in addition to field effect transistors. The first unidirectional device VD1 and the second unidirectional device VD2 may be, besides body diodes of the first switching tube Q1 and the second switching tube Q2, also be flywheel diodes connected in parallel separately.

In an embodiment, when the first switching tube Q1 and the second switching tube Q2 are field effect tubes, the first end of the first switching tube Q1 and the second switching tube Q2 are sources, the second end is a drain, and the third end is a gate. The first unidirectional device VD1 and the second unidirectional device VD2 may be coupled as a common cathode or as a common anode.

In this embodiment, the sources of the first switching tube and the second switching tube are coupled, and the drains are respectively coupled to the charging port and the charging management circuit, so that the first switching tube and the second switching tube can be controlled to be turned on and off to avoid affecting the charging of the battery. Meanwhile, the coupling mode of the first unidirectional device and the second unidirectional device is common cathode or common anode, so that the coupling complexity of the first unidirectional device and the second unidirectional device is reduced, current backflow is prevented, and the reliability of the charging protection circuit is improved.

The working principle of the first switching tube Q1 and the second switching tube Q2 for preventing current from flowing backward will be described by taking the P-type switching tube as the first switching tube Q1 and the second switching tube Q2 and the common cathode coupling mode as the first unidirectional device VD1 and the second unidirectional device VD2 as examples. When the first switching tube Q1 and the second switching tube Q2 are required to be turned on, the power management circuit 22 outputs a low level to the gates of the first switching tube Q1 and the second switching tube Q2, and the gate voltages of the first switching tube Q1 and the second switching tube Q2 are 0V. The voltage of the second end of the first switching tube Q1 is the voltage of the charging port Vbus, and the voltages of the first ends of the first switching tube Q1 and the second switching tube Q2 are the voltage of the charging port Vbus minus 0.7V. The gate-source voltage of the first switching transistor Q1 is 0.7V minus the voltage of the charging port Vbus, which is smaller than the threshold voltage of the first switching transistor Q1, and the first switching transistor Q1 is turned on. The voltages of the first ends of the first and second switching tubes Q1 and Q2 become the voltage of the charging port Vbus. The gate-source voltage of the second switching transistor Q2 is 0.7V minus the voltage of the charging port Vbus and is smaller than the threshold voltage of the second switching transistor Q2, and the second switching transistor Q2 is turned on. When the first switching transistor Q1 and the second switching transistor Q2 are required to be turned off, the power management circuit 22 outputs a high level to the gates of the first switching transistor Q1 and the second switching transistor Q2, and the gate-source voltages of the first switching transistor Q1 and the second switching transistor Q2 are turned off due to being greater than the respective threshold voltages.

Illustratively, a current limiting resistor is coupled between the first and third ends of the first and second switching tubes Q1 and Q2.

In one embodiment, as shown in fig. 5, the burn-proof unit 12 includes a third switching tube Q3. The third switching tube Q3 has a first end coupled to the ground GND, a second end coupled to a second end of the switching unit 111 (a second end of the first switching tube Q1), and a third end coupled to a third end of the charge management circuit 20. The third switching tube Q3 may be an N-type switching tube or a P-type switching tube. The first end of the third switching tube Q3 is a source electrode, the second end is a drain electrode, and the third end is a grid electrode. When a short circuit problem occurs, the charge management circuit 20 sends out a first control signal to turn on the third switching tube Q3. When charging normally, the charge management circuit 20 sends out a second control signal to turn off the third switching tube Q3.

In this embodiment, the third switching tube is used as the burn-proof unit, so that the charge management circuit can be timely protected when a short circuit problem occurs, and the complexity of the structure and control of the charge protection circuit is reduced.

In one embodiment, as shown in fig. 6, the charge management circuit 20 includes a charge pump 21 and a power management circuit 22. The first terminal of the charge pump 21 is used as the first terminal of the charge management circuit 20, the second terminal of the charge pump 21 is used as the second terminal of the charge management circuit 20, and the first terminal of the power management circuit 22 is used as the third terminal of the charge management circuit 20. The first terminal of the charge pump 21 may be, for example, an input terminal Vin of the charge pump 21, the second terminal of the charge pump 21 may be, for example, an overvoltage protection terminal OVP of the charge pump 21, and the first terminal of the power management circuit 22 may be, for example, an anti-burn terminal Gate of the power management circuit 22.

In this embodiment, since the charge management circuit includes the charge pump and the power management circuit, the battery can be charged quickly by the charge pump, and the battery can be charged normally by the power management circuit. The charge pump and the power supply management circuit are combined to form the charge management circuit, so that the efficiency of charging the battery is improved.

Illustratively, the charge management circuit 20 may include a power management circuit 22 in addition to the charge pump 21 and the power management circuit 22, instead of the charge pump 21. At this time, the first terminal of the charge management circuit 20 is the second terminal of the power management circuit 22, and the charge management circuit 20 can only charge the battery normally. The second terminal of the power management circuit 22 may be, for example, the input terminal Vin of the power management circuit 22.

The Power Management circuit 22 may be, for example, a Power Management chip (PMIC).

Illustratively, the charge management circuit 20 also includes a processor 420. When the charge management circuit 20 includes the power management circuit 22 without including the charge pump 21, if the power management circuit 22 includes the overvoltage protection terminal OVP, the overvoltage protection terminal OVP of the power management circuit 22 serves as the overvoltage protection terminal OVP of the charge management circuit 20, i.e., the third terminal of the power management circuit 22 serves as the second terminal of the charge management circuit 20. If the power management circuit 22 does not include the over voltage protection terminal OVP, the first terminal of the processor 420 serves as the second terminal of the charge management circuit 20. The first end of the processor 420 may be, for example, the first control end C1 of the processor 420.

In an embodiment, the charging protection circuit 10 further comprises a second overvoltage protection unit 13. The second overvoltage protection unit 13 has a first terminal coupled to the second terminal of the power management circuit 22, a second terminal coupled to the first terminal of the switching unit 111, and a third terminal coupled to the first terminal of the processor 420.

In this embodiment, since the charging management circuit includes a power management circuit, an overvoltage problem may occur in the power management circuit. Through the second overvoltage protection unit, the charging port and the power management circuit can be disconnected when an overvoltage problem occurs, so that the power management circuit is prevented from being damaged.

In one embodiment, as shown in fig. 7, the second overvoltage protection unit 13 includes a fourth switching tube Q4. The fourth switching tube Q4 has a first end coupled to the second end of the power management circuit 22, a second end coupled to the first end of the switching unit 111 (the second end of the second switching tube Q2), and a third end coupled to the first end of the processor 420. Wherein, a third unidirectional device VD3 is connected in parallel between the first end and the second end of the fourth switching tube Q4. The fourth switching tube Q4 is controlled to be turned off when the battery is charged rapidly. The fourth switching tube Q4 is controlled to be turned on when the battery is normally charged. Although the charge voltage remaining in the power management circuit 22 may be input to the first terminal of the charge pump 21 through the third unidirectional device VD3, the withstand voltage of the charge pump 21 is high without damage.

In this embodiment, the fourth switching tube is used as the second overvoltage protection unit to perform overvoltage protection on the power management circuit, and different modes of control are performed when different charging strategies are adopted on the battery, so that the complexity of the circuit structure of the second overvoltage protection unit is reduced.

In one embodiment, as shown in fig. 8, the second overvoltage protection unit 13 further includes a fifth switching tube Q5. The first end of the fifth switching tube Q5 is coupled to the first end of the fourth switching tube Q4, the second end is coupled to the second end of the power management circuit 22, and the third end is coupled to the third end of the fourth switching tube Q4. A fourth unidirectional device VD4 is connected in parallel between the first end and the second end of the fifth switching tube Q5, and the setting directions of the fourth unidirectional device VD4 and the third unidirectional device VD3 are opposite.

In this embodiment, by providing the fifth switching transistor, the charging voltage remaining in the power management circuit can be further prevented from flowing backward due to the formation of a current. Meanwhile, when the first unidirectional device or the second unidirectional device playing a role in preventing backflow is damaged, the third unidirectional device and the fourth unidirectional device can prevent the power management circuit from being damaged, so that the reliability of the charging protection circuit is improved.

In one embodiment, the fourth switching tube Q4 is a field effect tube, and the body diode of the fourth switching tube Q4 forms a third unidirectional device VD3.

In this embodiment, when the fourth switching tube is a field effect tube, the body diode of the fourth switching tube forms a third unidirectional device, and freewheeling can be realized without connecting the freewheeling diode in parallel, thereby reducing the complexity of the structure of the charging protection circuit. The body diode of the fourth switching tube is parasitic on the fourth switching tube and cannot be separated, and the fourth unidirectional device prevents current from flowing backwards, so that the damage of the charge management circuit is avoided.

In one embodiment, the fifth switching transistor Q5 is a field effect transistor, and the body diode of the fifth switching transistor Q5 forms the fourth unidirectional device VD4.

In this embodiment, when the fifth switching tube is a field effect tube, the body diode of the fifth switching tube forms a fourth unidirectional device, and freewheeling can be realized without connecting the freewheeling diode in parallel, thereby reducing the complexity of the structure of the charging protection circuit. The body diode of the fifth switching tube is parasitic on the fifth switching tube and cannot be separated, and the third unidirectional device prevents current from flowing backwards, so that the damage of the charge management circuit is avoided.

It is understood that the fourth switching transistor Q4 and the fifth switching transistor Q5 may be transistors such as insulated gate bipolar transistors, in addition to field effect transistors. The third unidirectional device VD3 and the fourth unidirectional device VD4 may be free wheeling diodes separately connected in parallel, in addition to the body diodes of the fourth switching tube Q4 and the fifth switching tube Q5.

In an embodiment, when the fourth switching tube Q4 and the fifth switching tube Q5 are field effect tubes, the first ends of the fourth switching tube Q4 and the fifth switching tube Q5 are sources, the second ends are drains, and the third ends are gates. The fourth switching tube Q4 and the fifth switching tube Q5 can be N-type switching tubes or P-type switching tubes. The third unidirectional device VD3 and the fourth unidirectional device VD4 may be coupled as a common cathode or as a common anode.

In this embodiment, the sources of the fourth switching tube and the fifth switching tube are coupled, and the drains are respectively coupled to the second switching tube and the power management circuit, so that the fourth switching tube and the fifth switching tube can be controlled to be turned on and off to avoid affecting the charging of the battery. The fourth switching tube and the fifth switching tube can be of N type or P type, so that the universality of the charging protection circuit is improved. Meanwhile, the coupling mode of the third unidirectional device and the fourth unidirectional device is common cathode or common anode, so that the coupling complexity of the third unidirectional device and the fourth unidirectional device is reduced, current backflow is avoided, and the reliability of the charging protection circuit is improved.

In one embodiment, the third terminal of the charge pump 21, the fourth terminal of the power management circuit 22, and the second terminal of the processor 420 are all coupled to the ground GND. The third terminal of the processor 420 is coupled to the power supply VCC, the fourth terminal is coupled to the fourth terminal of the charge pump 21, and the fifth terminal is coupled to the fifth terminal of the power management circuit 22. The fifth terminal of the charge pump 21 and the sixth terminal of the power management circuit 22 are both coupled to a battery. The third terminal of the charge pump 21 may be, for example, a common terminal AGND of the charge pump 21, the fourth terminal of the charge pump 21 may be, for example, an enable terminal En of the charge pump 21, and the fifth terminal of the charge pump 21 may be, for example, a voltage output terminal of the charge pump 21. The fourth terminal of the power management circuit 22 may be, for example, a common terminal AGND of the power management circuit 22, the fifth terminal of the power management circuit 22 may be, for example, an enable terminal En of the power management circuit 22, and the sixth terminal of the power management circuit 22 may be, for example, a voltage output terminal of the power management circuit 22. The second end of the processor 420 may be, for example, a common end AGND of the processor 420, the third end of the processor 420 may be, for example, an input end Vin of the processor 420, the fourth end of the processor 420 may be, for example, a second control end C2 of the processor 420, and the fifth end of the processor 420 may be, for example, a third control end C3 of the processor 420.

When the battery is charged rapidly, the processor 420 turns off the fourth switching tube Q4 and the fifth switching tube Q5 and controls the charge pump 21 to charge the battery. When the battery is charged normally, the processor 420 turns on the fourth switching transistor Q4 and the fifth switching transistor Q5 and controls the power management circuit 22 to charge the battery. When an overvoltage or short circuit problem occurs, the processor 420 turns off the fourth switching tube Q4 and the fifth switching tube Q5 and disables the charge function of the charge pump 21 and the power management circuit 22. The first control terminal C1, the second control terminal C2, and the third control terminal C3 may be, for example, input/output terminals of the processor 420. When the battery is charged quickly, the processor 420 enables the charging function of the charge pump 21 through the fourth terminal of the charge pump 21, and the processor 420 disables the charging function of the power management circuit 22 through the fifth terminal of the power management circuit 22. When the battery is normally charged, the processor 420 disables the charging function of the charge pump 21 through the fourth terminal of the charge pump 21, and the processor 420 enables the charging function of the power management circuit 22 through the fifth terminal of the power management circuit 22.

In this embodiment, the processor can control the on-off of the fourth switching tube and the fifth switching tube through the signal of the first control end, and can prevent the charging port from being coupled with the power management circuit to protect the power management circuit, so that the complexity of controlling the fourth switching tube and the fifth switching tube is reduced.

In one embodiment, as shown in fig. 9, the charge protection circuit 10 further includes a voltage detection unit 14. The first terminal of the voltage detecting unit 14 is coupled to both the second terminal of the switching unit 111 and the second terminal of the burn-out preventing unit 12, the second terminal is coupled to the ground GND, the third terminal is coupled to the fourth terminal of the charge managing circuit 20, and the charge managing circuit 20 detects the voltage of the charging port Vbus through the voltage detecting unit 14. The fourth terminal of the charge management circuit 20 may be, for example, the voltage detection terminal Vsen of the charge management circuit 20.

In this embodiment, the voltage detection unit can determine whether the voltage of the charging port changes, and output the corresponding short-circuit voltage to the charging management circuit for identification when the short-circuit problem occurs, so that the charging management circuit takes corresponding protection measures for the short-circuit problem to improve the reliability of the charging protection circuit.

In one embodiment, as shown in fig. 10, the voltage detection unit 14 includes a fixed resistor R1 and a thermistor R2. The charge management circuit 20 includes a charge pump 21 and a power management circuit 22, with a seventh terminal of the power management circuit 22 being a fourth terminal of the charge management circuit 20. The first end of the fixed resistor R1 is coupled to both the second end of the switching unit 111 (the second end of the first switching tube Q1) and the second end of the burn-out preventing unit 12 (the second end of the third switching tube Q3). The first terminal of the thermistor R2 is coupled to the second terminal of the fixed resistor R1 as a third terminal of the voltage detecting unit 14, and the second terminal is coupled to the ground GND. The seventh terminal of the power management circuit 22 may be, for example, the voltage detection terminal Vsen of the power management circuit 22. When a short circuit problem occurs, the resistance of the thermistor R2 decreases, and the voltage detected by the power management circuit 22 decreases. The power management circuit 22 takes corresponding protection measures to perform short-circuit protection according to the detected voltage.

In this embodiment, the fixed resistor and the thermistor are connected in series as the voltage detection unit, so that the voltage of the charging port can be detected when the charging process is normal. When a short circuit problem occurs, the thermistor can automatically reduce the resistance value due to heating, so that the power management circuit can recognize the current. Whether the short circuit problem occurs is reflected through the voltage division of the thermistor, and the complexity of the structure and the control of the charging protection circuit is reduced.

In one embodiment, as shown in fig. 11, the charge protection circuit 10 further includes a control unit 15. The first terminal of the control unit 15 is coupled to the second terminal of the charge management circuit 20, the second terminal is coupled to the third terminal of the charge management circuit 20, and the third terminal is coupled to the third terminal of the burn-out preventing unit 12. The first end of the control unit 15 may be, for example, a first input end of the control unit 15, the second end of the control unit 15 may be, for example, a second input end of the control unit 15, and the third end of the control unit 15 may be, for example, an output end of the control unit 15. The charge management circuit 20 controls the operation state of the burn-out prevention unit 12 through the control unit 15. When the short circuit problem occurs, the control unit 15 delays the first control signal sent by the charge management circuit 20, so that the burn-in preventing unit 12 is turned on in a delayed manner.

In this embodiment, by adding the control unit between the power management circuit and the burn-proof unit, the burn-proof unit is turned on with a delay, so that the burn-proof unit is prevented from being turned on before the first overvoltage protection unit is turned off. The anti-burning unit is conducted after the first overvoltage protection unit is turned off, so that the possibility of current backflow is further reduced, and the reliability of the charging protection circuit is improved.

In one embodiment, as shown in fig. 12 AND 13, when the switching transistors in the first overvoltage protection unit 11 AND the burn-in protection unit 12 are N-type field effect transistors, the control unit 15 includes AND logic gates AND. The AND logic gate AND has a first terminal coupled to a third terminal (third terminal of the first switching tube Q1 AND the second switching tube Q2) of the switching unit 111, a second terminal coupled to a first terminal of the power management circuit 22 in the charge management circuit 20, AND a third terminal coupled to a third terminal (third terminal of the third switching tube Q3) of the burn-out preventing unit 12. The first end of the AND logic gate may be, for example, an inverting input of the AND logic gate, the second end of the AND logic gate may be, for example, a non-inverting input of the AND logic gate, AND the third end of the AND logic gate may be, for example, an output of the AND logic gate. When a short circuit problem occurs, the power management circuit 22 detects a voltage drop at the first end of the thermistor R2 AND outputs a high level to the AND logic gate AND. Since the third terminals of the first switching tube Q1 AND the second switching tube Q2 are at high level, AND the AND logic gate AND outputs low level, the third switching tube Q3 is still in the off state. Since the charging device providing the charging port Vbus can detect that a short circuit problem occurs, the charging device gradually decreases the voltage of the charging port Vbus according to the burn-in prevention process of the charging protocol. When the voltage of the charge port Vbus decreases to the undervoltage threshold of the charge pump 21, the charge pump 21 outputs a low level to turn off the first switching transistor Q1 and the second switching transistor Q2. The first end of AND logic gate AND goes low, AND logic gate AND output The high level turns on the third switching tube Q3, and prevents the charge voltage remaining in the charge pump 21 and the power management circuit 22 from flowing backward from the third switching tube Q3 to the ground GND while preventing burn-out. Wherein V is _c V is the voltage output to the third terminal of the third switching tube Q3 by AND logic gate _G V is the voltage of the third end of the first switching tube Q1 and the second switching tube Q2 _t To the voltage AND logic gate of the power management circuit 22, V _R Is the voltage at the first end of the thermistor R2.

In this embodiment, the control unit is added to the charging protection circuit, and the third switching tube is turned on after the first switching tube and the second switching tube are turned off, so that the situation that the residual charging voltage in the charge pump and the power management circuit forms current to flow backward to the ground terminal is further avoided, and the reliability of the charging protection circuit is improved.

For example, the control unit 15 may also be another logic gate when the types of switching tubes in the first overvoltage protection unit 11 and the burn-in protection unit 12 change. For example, when the switching transistors in the first overvoltage protection unit 11 and the burn-proof unit 12 are P-type switching transistors, the control unit 15 is a nand logic gate with a first end and a second end both being non-inverting input ends. Alternatively, the control unit 15 may be a delay unit only, with an input coupled to the third terminal of the charge management circuit 20 and an output coupled to the third terminal of the burn-out prevention unit 12. The delay time of the delay unit can be determined in advance through testing.

Illustratively, in addition to directly detecting the occurrence of the short circuit problem by the charging device, a prompt signal may be sent to the processor 420 by the power management circuit 22, and the processor 420 disables the charging functions of the charge pump 21 and the power management circuit 22 after receiving the prompt signal. Since the battery has been disconnected from the charging circuit, the charging device can determine that a short circuit problem has occurred according to a change in the output current, and gradually reduce the voltage of the charging port Vbus.

In one exemplary embodiment, a charging circuit is provided that includes the charge protection circuit 10 and the charge management circuit 20 described above. The charge protection circuit 10 is coupled with the charge management circuit 20.

Illustratively, the charge management circuit 20 includes a charge pump 21 and a power management circuit 22. The charge protection circuit 10 is coupled to both the charge pump 21 and the power management circuit 22.

In one exemplary embodiment, an electronic device is provided, such as a cell phone, a notebook computer, a tablet computer, a wearable device, and the like. The electronic device comprises a charging circuit as described above.

Referring to fig. 14, an electronic device 400 may include one or more of the following components: a processing component 402, a memory 404, a power supply component 406, a multimedia component 408, an audio component 410, an input/output (I/O) interface 412, a sensor component 414, and a communication component 416.

The processing component 402 generally controls overall operation of the electronic device 400, such as operations associated with display, telephone calls, data communications, camera operations, and recording operations. The processing component 402 may include one or more processors 420 (the processor 420 in the charge management circuit 20) to execute instructions to perform all or part of the steps of the methods described above. Further, the processing component 402 can include one or more modules that facilitate interaction between the processing component 402 and other components. For example, the processing component 402 may include a multimedia module to facilitate interaction between the multimedia component 408 and the processing component 402.

The memory 404 is configured to store various types of data to support operations at the electronic device 400. Examples of such data include instructions for any application or method operating on electronic device 400, contact data, phonebook data, messages, pictures, videos, and the like. The memory 404 may be implemented by any type of volatile or non-volatile memory terminal or combination thereof, such as Static Random Access Memory (SRAM), electrically erasable programmable read-only memory (EEPROM), erasable programmable read-only memory (EPROM), programmable read-only memory (PROM), read-only memory (ROM), magnetic memory, flash memory, magnetic or optical disk.

The power supply component 406 provides power to the various components of the electronic device 400. The power components 406 may include a power management system, one or more power supplies, and other components associated with generating, managing, and distributing power for the electronic device 400.

The multimedia component 408 includes a screen between the electronic device 400 and the user that provides an output interface. In some embodiments, the screen may include a Liquid Crystal Display (LCD) and a Touch Panel (TP). If the screen includes a touch panel, the screen may be implemented as a touch screen to receive input signals from a user. The touch panel includes one or more touch sensors to sense touches, swipes, and gestures on the touch panel. The touch sensor may sense not only the boundary of a touch or sliding action, but also the duration and pressure associated with the touch or sliding operation. In some embodiments, the multimedia component 408 includes a front camera module and/or a rear camera module. When the electronic device 400 is in an operation mode, such as a photographing mode or a video mode, the front camera module and/or the rear camera module may receive external multimedia data. Each of the front camera module and the rear camera module may be a fixed optical lens system or have focal length and optical zoom capabilities.

The audio component 410 is configured to output and/or input audio signals. For example, the audio component 410 includes a Microphone (MIC) configured to receive external audio signals when the electronic device 400 is in an operational mode, such as a call mode, a recording mode, and a voice recognition mode. The received audio signals may be further stored in the memory 404 or transmitted via the communication component 416. In some embodiments, audio component 410 further includes a speaker for outputting audio signals.

The I/O interface 412 provides an interface between the processing component 402 and peripheral interface modules, which may be a keyboard, click wheel, buttons, etc. These buttons may include, but are not limited to: homepage button, volume button, start button, and lock button.

The sensor assembly 414 includes one or more sensors for providing status assessment of various aspects of the electronic device 400. For example, the sensor assembly 414 may detect an on/off state of the electronic device 400, a relative positioning of the components, such as a display and keypad of the electronic device 400, the sensor assembly 414 may also detect a change in position of the electronic device 400 or a component of the electronic device 400, the presence or absence of a user's contact with the electronic device 400, an orientation or acceleration/deceleration of the electronic device 400, and a change in temperature of the electronic device 400. The sensor assembly 414 may include a proximity sensor configured to detect the presence of nearby objects in the absence of any physical contact. The sensor assembly 414 may also include a light sensor, such as a CMOS or CCD image sensor, for use in imaging applications. In some embodiments, the sensor assembly 414 may also include an acceleration sensor, a gyroscopic sensor, a magnetic sensor, a pressure sensor, or a temperature sensor.

The communication component 416 is configured to facilitate communication between the electronic device 400 and other terminals, either wired or wireless. The electronic device 400 may access a wireless network based on a communication standard, such as WiFi, 2G, 3G, 4G, 5G, or a combination thereof. In one exemplary embodiment, the communication component 416 receives broadcast signals or broadcast-related information from an external broadcast management system via a broadcast channel. In one exemplary embodiment, the communication component 416 further includes a Near Field Communication (NFC) module to facilitate short range communications. For example, the NFC module may be implemented based on Radio Frequency Identification (RFID) technology, infrared data association (IrDA) technology, ultra Wideband (UWB) technology, bluetooth (BT) technology, and other technologies.

In an exemplary embodiment, electronic device 400 may be implemented by one or more Application Specific Integrated Circuits (ASICs), digital Signal Processors (DSPs), digital signal processing terminals (DSPDs), programmable Logic Devices (PLDs), field Programmable Gate Arrays (FPGAs), controllers, microcontrollers, microprocessors, or other electronic elements.

Other embodiments of the disclosure will be apparent to those skilled in the art from consideration of the specification and practice of the disclosure disclosed herein. This disclosure is intended to cover any adaptations, uses, or adaptations of the disclosure following the general principles of the disclosure and including such departures from the present disclosure as come within known or customary practice within the art to which the disclosure pertains. It is intended that the specification and examples be considered as exemplary only, with a true scope and spirit of the disclosure being indicated by the following claims.

It is to be understood that the present disclosure is not limited to the precise arrangements and instrumentalities shown in the drawings, and that various modifications and changes may be effected without departing from the scope thereof. The scope of the present disclosure is limited only by the appended claims.

Claims

1. A charge protection circuit, the charge protection circuit comprising:

2. The charge protection circuit of claim 1, wherein the switching unit comprises a first switching tube and a second switching tube, a first end of the first switching tube is coupled to a first end of the second switching tube, a second end of the first switching tube is coupled to the charging port, a second end of the second switching tube is coupled to a first end of the charge management circuit, and third ends of the first switching tube and the second switching tube are both coupled to a second end of the charge management circuit; the first switch tube is coupled with a first unidirectional device in parallel, the backflow prevention unit comprises a second unidirectional device, the second unidirectional device is coupled with the second switch tube in parallel, and the arrangement directions of the first unidirectional device and the second unidirectional device are opposite.

3. The charge protection circuit of claim 2, wherein the first switching tube is a field effect tube, and a body diode of the first switching tube forms the first unidirectional device; and/or the second switching tube is a field effect tube, and the body diode of the second switching tube forms the second unidirectional device.

4. The charge protection circuit of claim 1, wherein the burn-out prevention unit comprises:

5. The charge protection circuit of claim 1, wherein the charge management circuit comprises a charge pump and a power management circuit, a first terminal of the charge pump being a first terminal of the charge management circuit, a second terminal of the charge pump being a second terminal of the charge management circuit, and a first terminal of the power management circuit being a third terminal of the charge management circuit.

6. The charge protection circuit of claim 5, wherein the charge management circuit further comprises a processor; the charge protection circuit further includes:

7. The charge protection circuit of claim 6, wherein the second overvoltage protection unit comprises a fourth switching tube and a fifth switching tube, a first end of the fourth switching tube is coupled to a first end of the fifth switching tube, a second end of the fourth switching tube is coupled to a first end of the switching unit, a second end of the fifth switching tube is coupled to a second end of the power management circuit, and third ends of the fourth switching tube and the fifth switching tube are both coupled to a first end of the processor; the third unidirectional device is connected in parallel with the fourth switching tube, the fourth unidirectional device is connected in parallel with the fifth switching tube, and the setting directions of the third unidirectional device and the fourth unidirectional device are opposite.

8. The charge protection circuit of claim 1, further comprising:

9. The charge protection circuit according to claim 8, wherein the voltage detection unit includes:

10. The charge protection circuit according to any one of claims 1 to 9, further comprising:

11. The charge protection circuit of claim 10, wherein the control unit comprises:

12. A charging circuit comprising a charging management circuit and a charging protection circuit as claimed in any one of claims 1 to 11, the charging protection circuit being coupled to the charging management circuit.

13. The charging circuit of claim 12, wherein the charge management circuit comprises a charge pump and a power management circuit, the charge protection circuit being coupled to both the charge pump and the power management circuit.

14. An electronic device, characterized in that it comprises a charging circuit as claimed in claim 12 or 13.