CN113725964A

CN113725964A - Charge and discharge control circuit of three-cell battery, control method of charge and discharge control circuit and terminal equipment

Info

Publication number: CN113725964A
Application number: CN202110943887.8A
Authority: CN
Inventors: 陈佳; 刘小勇
Original assignee: Meizu Technology Co Ltd
Current assignee: Meizu Technology Co Ltd
Priority date: 2021-08-17
Filing date: 2021-08-17
Publication date: 2021-11-30

Abstract

The utility model relates to a charge-discharge control circuit of a three-cell battery, a control method thereof and a terminal device, wherein the charge-discharge control circuit of the three-cell battery comprises a booster circuit, a control circuit and at least one first charge pump, the control circuit is used for controlling the opening and closing time periods of the booster circuit and the first charge pump according to the setting parameters of an external power adapter and the setting parameters of the three-cell battery; the boost circuit is used for charging the three-cell battery in a trickle charge stage, a constant-voltage charge stage and a charge stop stage of the three-cell battery; the first charge pump is used for charging the three-cell battery in a constant current charging stage of the three-cell battery; the output voltage of the first charge pump is smaller than the input voltage of the first charge pump, and the output current of the first charge pump is larger than the input current of the first charge pump. Through the technical scheme, the problem of heating of the battery circuit board is improved, the control process is simple and flexible, and the charging efficiency of the three-cell battery is improved.

Description

Charge and discharge control circuit of three-cell battery, control method of charge and discharge control circuit and terminal equipment

Technical Field

The disclosure relates to the technical field of charging, in particular to a charging and discharging control circuit of a three-cell battery, a control method of the charging and discharging control circuit and terminal equipment.

Background

The current terminal equipment mainly uses a single-cell battery for charging, but because the voltage of the fully charged single-cell battery is about 4.5V, when the charging current of the single-cell battery exceeds 8A, the problem that the circuit board of the battery side generates heat seriously occurs. In addition, the battery connector with smaller impedance and larger current needs to be replaced, which results in the cost increase of charging the single-cell battery, and increases the difficulty of routing and heat dissipation of the battery-side Circuit Board PCB (Printed Circuit Board), and the charging power of the single-cell battery reaches the bottleneck at about 36W.

Disclosure of Invention

In order to solve the technical problem or at least partially solve the technical problem, the present disclosure provides a charge and discharge control circuit of a three-cell battery, a control method thereof, and a terminal device, which improve the problem of heat generation of a battery circuit board, have a simple and flexible control process, and improve the charging efficiency of the three-cell battery.

In a first aspect, an embodiment of the present disclosure provides a charge and discharge control circuit for a three-cell battery, including:

the external power adapter is respectively and electrically connected with the boost circuit, the at least one first charge pump and the control circuit, the control circuit is respectively and electrically connected with the boost circuit and the at least one first charge pump, and the three-cell battery is respectively and electrically connected with the boost circuit, the control circuit and the at least one first charge pump;

the control circuit is used for controlling the on and off time periods of the boost circuit and the first charge pump according to the set parameters of the external power adapter and the set parameters of the three-cell battery;

the boost circuit is used for charging the three-cell battery in a trickle charge stage, a constant-voltage charge stage and a charge cut-off stage of the three-cell battery;

the first charge pump is used for charging the three-cell battery in a constant current charging stage of the three-cell battery; the output voltage of the first charge pump is smaller than the input voltage of the first charge pump, and the output current of the first charge pump is larger than the input current of the first charge pump.

Optionally, the method further comprises:

the first voltage reduction circuit is electrically connected with the external power adapter, the control circuit and the system power supply module respectively, and the discharge circuit is electrically connected with the control circuit, the three-cell battery and the system power supply module respectively;

the control circuit is used for controlling the opening and closing time periods of the first voltage reduction circuit and the discharge circuit according to set parameters of the three-cell battery;

the first voltage reduction circuit is used for supplying power to the system power supply module in a constant-current charging stage, a constant-voltage charging stage and a charging stopping stage of the three-cell battery;

the discharging circuit is used for supplying power to the system power supply module in the discharging stage of the three-cell battery.

Optionally, the discharge circuit comprises a second voltage reduction circuit or at least one second charge pump.

Optionally, the first charge pump includes a plurality of first switches and N first capacitors, and the first switches are configured to control a series-parallel connection state of the first capacitors in the first charge pump according to their own switch states so that an output voltage of the first charge pump is equal to 1/N of an input voltage of the first charge pump; wherein N is an integer greater than 1;

the second charge pump comprises a plurality of second switches and M second capacitors, and the second switches are used for controlling the series-parallel connection state of the second capacitors in the second charge pump according to the switch states of the second switches so that the output voltage of the second charge pump is equal to 1/M of the input voltage of the second charge pump; wherein M is an integer greater than 1.

Optionally, the first charge pump is operated alternately in a first period and a second period;

in the first time interval, the first switch controls the first capacitor to form a series connection relation according to the switch state of the first switch;

in the second time interval, the first switch controls the first capacitor to form a parallel connection relation according to the switching state of the first switch;

the second charge pump works in a third period and a fourth period alternately;

in the third time period, the second switch controls the second capacitor to form a series connection relation according to the switch state of the second switch;

and in the fourth period, the second switch controls the second capacitor to form a parallel connection relation according to the switch state of the second switch.

Optionally, the first voltage-reducing circuit includes a third switch, a fourth switch, and a first inductor, the third switch is connected in series between the input terminal of the first voltage-reducing circuit and the first terminal of the first inductor, the fourth switch is connected in series between the first node and a ground terminal, and the second terminal of the first inductor serves as the output terminal of the first voltage-reducing circuit; wherein the first node is a series node of the third switch and the first inductor;

the second voltage reduction circuit comprises a fifth switch, a sixth switch and a second inductor, the fifth switch is connected between the input end of the second voltage reduction circuit and the first end of the second inductor in series, the sixth switch is connected between a second node and a ground end in series, and the second end of the second inductor is used as the output end of the second voltage reduction circuit; wherein the second node is a series node of the fifth switch and the second inductor.

Optionally, the boost circuit comprises:

the seventh switch is connected between a first end of the third inductor and the output end of the booster circuit in series, the eighth switch is connected between a third node and a ground end in series, and a second end of the third inductor is used as the input end of the booster circuit; wherein the third node is a series node of the seventh switch and the third inductor.

In a second aspect, an embodiment of the present disclosure further provides a charge and discharge control method for a three-cell battery, where the charge and discharge control method is executed by the charge and discharge control circuit for a three-cell battery according to the first aspect, and the charge and discharge control method for a three-cell battery includes:

acquiring set parameters of the external power adapter and set parameters of the three-cell battery;

judging the working stage of the three-cell battery according to the set parameters of the external power adapter and the set parameters of the three-cell battery;

in the trickle charge stage, the constant-voltage charge stage and the charge cut-off stage, controlling the boosting circuit to charge the three-cell battery;

and in the constant current charging stage, controlling the first charge pump to charge the three-cell battery.

Optionally, the charge and discharge control circuit further includes a first voltage reduction circuit and a discharge circuit, the first voltage reduction circuit is electrically connected to the external power adapter, the control circuit and the system power supply module, and the discharge circuit is electrically connected to the control circuit, the three-cell battery and the system power supply module;

the charge and discharge control method of the three-cell battery further comprises the following steps:

in the constant-current charging stage, the constant-voltage charging stage and the charging stopping stage, controlling the first voltage reduction circuit to supply power to the system power supply module;

and in the discharging stage, controlling the discharging circuit to supply power to the system power supply module.

In a third aspect, an embodiment of the present disclosure further provides a terminal device, which includes a three-cell battery and the charge and discharge control circuit of the three-cell battery according to the first aspect.

Compared with the prior art, the technical scheme provided by the embodiment of the disclosure has the following advantages:

the three-cell battery adopted by the embodiment of the disclosure effectively solves the bottleneck that the single-cell battery cannot further realize high-power charging, improves the problem of heating of a battery circuit board caused by the single-cell battery, improves charging safety, and is beneficial to realizing high-power charging of 100W, 120W and above. In addition, in the trickle charge stage, the constant voltage charge stage and the charge cut-off stage of the three-cell battery, the boost circuit is used for charging the three-cell battery, the control process is simpler, the control flexibility is higher, in the constant current charge stage of the three-cell battery, the three-cell battery is charged by using the first charge pump, the output voltage of the first charge pump is smaller than the input voltage of the first charge pump, the output current of the first charge pump is larger than the input current of the first charge pump, the current transmitted on a charging wire rod can be reduced when the large current charge is realized, the heat generation on the charging wire rod is improved, the heat generation of a charging chip and a PCB can be reduced, namely the heat generation of the whole charging circuit is reduced, and the higher charging efficiency of the three-cell battery is ensured.

Drawings

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

In order to more clearly illustrate the embodiments or technical solutions in the prior art of the present disclosure, the drawings used in the description of the embodiments or prior art will be briefly described below, and it is obvious for those skilled in the art that other drawings can be obtained according to the drawings without inventive exercise.

Fig. 1 is a schematic structural diagram of a charge and discharge control circuit of a three-cell battery provided in an embodiment of the present disclosure;

fig. 2 is a schematic structural diagram of a charge and discharge control circuit of another three-cell battery provided in the embodiment of the present disclosure;

fig. 3 is a schematic structural diagram of a first charge pump according to an embodiment of the disclosure;

fig. 4 is a schematic structural diagram of another first charge pump according to an embodiment of the disclosure;

fig. 5 is a schematic structural diagram of a first voltage-reducing circuit according to an embodiment of the disclosure;

fig. 6 is a schematic structural diagram of a voltage boosting circuit according to an embodiment of the disclosure;

fig. 7 is a schematic flow chart of a charge and discharge control method for a three-cell battery according to an embodiment of the present disclosure.

Detailed Description

In order that the above objects, features and advantages of the present disclosure may be more clearly understood, aspects of the present disclosure will be further described below. It should be noted that the embodiments and features of the embodiments of the present disclosure may be combined with each other without conflict.

In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present disclosure, but the present disclosure may be practiced in other ways than those described herein; it is to be understood that the embodiments disclosed in the specification are only a few embodiments of the present disclosure, and not all embodiments.

Fig. 1 is a schematic structural diagram of a charge and discharge control circuit of a three-cell battery provided in an embodiment of the present disclosure. As shown in fig. 1, the charge and discharge control circuit of the three-cell battery includes a voltage boost circuit 1, a control circuit 2 and at least one first charge pump 3, fig. 1 exemplarily sets the charge and discharge control circuit to include the first charge pump 3, the external power adapter 4 is electrically connected to the voltage boost circuit 1, the at least one first charge pump 3 and the control circuit 2, the control circuit 2 is electrically connected to the voltage boost circuit 1 and the at least one first charge pump 3, and the three-cell battery 5 is electrically connected to the voltage boost circuit 1, the control circuit 2 and the at least one first charge pump 3. The external power adapter 4 may exemplarily be an AC/DC power adapter, i.e. a DC-to-AC power adapter.

The control circuit 2 is used for controlling the on and off periods of the boost circuit 1 and the first charge pump 3 according to the setting parameters of the external power adapter 4 and the setting parameters of the three-cell battery 5, the boost circuit 1 is used for charging the three-cell battery 5 in the trickle charging stage, the constant voltage charging stage and the charging cut-off stage of the three-cell battery 5, the first charge pump 3 is used for charging the three-cell battery 5 in the constant current charging stage of the three-cell battery 5, the output voltage of the first charge pump 3 is smaller than the input voltage of the first charge pump 3, and the output current of the first charge pump 3 is larger than the input current of the first charge pump 3.

The current terminal equipment mainly uses a single-cell battery for charging, but because the voltage of the fully charged single-cell battery is about 4.5V, when the charging current of the single-cell battery exceeds 8A, the problem that the circuit board of the battery side generates heat seriously occurs. In addition, the battery connector with smaller impedance and larger through-current needs to be replaced, so that the charging implementation cost is increased, the difficulty of wiring and heat dissipation of a circuit board at the battery end is increased, and the charging power at the single-cell battery end reaches the bottleneck at about 36W.

In order to realize larger charging power, the terminal equipment can be charged by adopting double-cell batteries, namely, two cells are arranged in one battery, and the two cells are in series connection, so that the charging voltage of the double-cell batteries is twice of that of the single-cell battery, for the same battery end charging power, the charging current of the double-cell batteries is half of that of the single-cell battery, the heating problem of the circuit board at the end of the double-cell battery is improved to some extent relative to the single-cell battery, the requirement on a battery connector is reduced, and the wiring and heat dissipation difficulty of the circuit board at the end of the battery is also reduced. However, the voltage after the two-cell battery is fully charged is about 9V, and when the charging current of the two-cell battery exceeds 10A, the problem that the end circuit board of the battery generates heat seriously occurs similarly. In addition, the charging rate of the dual-battery cell is still high, and a battery connector with smaller impedance and larger through-flow is also required to be replaced, so that the charging cost is increased, the difficulty in wiring and heat dissipation of a circuit board at the battery end is increased, and the charging power at the dual-battery cell end reaches the bottleneck at about 90W.

The embodiment of the present disclosure adopts the three-cell battery 5, that is, the battery includes three cells, the cells are in a series relationship, the charging voltage of the three-cell battery 5 is 1.5 times of the charging voltage of the dual-cell battery, for the charging power of the same battery end, the charging current of the three-cell battery 5 is 2/3 of the dual-cell charging current, the voltage of the fully charged three-cell battery 5 is about 13.5V, when the charging power is about 90W, the charging current of the three-cell battery 5 is about 6.67A, and the charging current of the dual-cell battery is 10A, which effectively reduces the charging current of the battery, improves the problem of heat generation of the circuit board, and improves the charging safety. In addition, the charging rate of the three-cell battery 5 is reduced, the requirement on a battery connector is further reduced, the charging implementation cost is reduced, the difficulty of wiring and heat dissipation of a battery side circuit board is reduced, and 100W, 120W and above high-power charging can be achieved by using the three-cell battery 5 to charge the terminal equipment. Therefore, the embodiment of the disclosure adopts the three-cell battery 5 to effectively solve the bottleneck that the single-cell battery cannot further realize high-power charging, improves the problem of heating of the battery circuit board caused by the single-cell battery, improves charging safety, and is beneficial to realizing high-power charging of 100W, 120W and above.

Specifically, the charging stage of the three-cell battery 5 includes a trickle charging stage, a constant current charging stage, a constant voltage charging stage and a charging stop stage, the trickle charging stage is understood as a pre-charging stage, which is a low current charging stage, the constant current charging stage is a stage of charging with a constant current, the charging voltage of the stage is gradually increased, the constant voltage charging stage is a stage of charging with a constant voltage, the charging current of the stage is gradually decreased, the charging current of the charging stop stage is gradually decreased, and when the charging current is smaller than a set value, that is, the charging current is decreased to a certain degree, the charging stage corresponds to a full state of the three-cell battery 5.

In the trickle charge stage of the three-cell battery 5, when the voltage of the three-cell battery 5 is lower than 9V, the maximum 0.1C, that is, a constant current of 0.1 coulomb, may be used to charge the three-cell battery 5, and at this time, the control circuit 2 determines the port type of the external power adapter 4. Illustratively, the Port type of the external power adapter 4 may be SDP (Standard Downstream Port), DCP (Dedicated Charging Port), or CDP (Charging Downstream Port), which is not specifically limited in this disclosure. At this time, the setting parameter of the external power adapter 4 includes the port type of the external power adapter 4, and the setting parameter of the three-cell battery 5 includes the voltage of the three-cell battery 5.

Specifically, when the port type of the external power adapter 4 is SDP, it indicates that the port is a USB (Universal Serial Bus) interface that can be plugged into a computer, and the through-current of the port is 500mA and the voltage of the port is 5V. When the port type of the external power adapter 4 is CDP, the port is similar to a hub and is a hub having a plurality of interfaces, and the current flowing through the port is 1A to 1.5A and the voltage is 5V. When the port type of the external power adapter 4 is DCP, the control circuit 2 does not perform a boost control protocol with the external power adapter 4. Under the three conditions, the output voltage of the external power adapter 4 is 5V, at this time, the control circuit 2 controls the boost circuit 1 to be turned on, the boost circuit 1 charges the three-cell battery 5 with a small current, and controls the first charge pump 3 to be turned off.

In the constant-current charging stage of the three-cell battery 5, when the control circuit 2 monitors that the charging voltage of the three-cell battery 5 is greater than a set voltage threshold and the charging current of the three-cell battery 5 is greater than a set current threshold, for example, 1A or 2A, the control circuit 2 controls the first charge pump 3 to be turned on, a boost control protocol is performed between the control circuit 2 and the external power adapter 4 to control the external power adapter 4 to output dynamic voltage and dynamic current to the first charge pump 3, at this time, the first charge pump 3 charges the three-cell battery 5 with a large current, and the control circuit 2 controls the boost circuit 1 to be turned off at the same time. At this time, the setting parameters of the three-cell battery 5 include the charging voltage of the three-cell battery 5 and the charging current of the three-cell battery 5.

In the constant-voltage charging stage and the charge cut-off stage of the three-cell battery 5, when the control circuit 2 monitors that the charging current of the three-cell battery 5 is smaller than the set current threshold, the control circuit 2 does not need to perform a boost control protocol with the external power adapter 4, and controls the external power adapter 4 to output a voltage lower than the voltage of the three-cell battery 5, where the voltage is, for example, 5V or 6V. At this time, the control circuit 2 controls the voltage boost circuit 1 to be turned on, and controls the first charge pump 3 to be turned off, that is, controls the voltage boost circuit 1 to charge the three-cell battery 5. At this time, the setting parameter of the three-cell battery 5 includes the charging current of the three-cell battery 5. It should be noted that, in the charging process of the three-cell battery 5, the voltage threshold and the current threshold may be set based on the charging requirement of the three-cell battery 5, and this is not specifically limited in this embodiment of the disclosure.

Therefore, the three-cell battery 5 adopted in the embodiment of the disclosure effectively solves the bottleneck that the single-cell battery cannot further realize high-power charging, improves the problem of heating of the battery circuit board caused by the single-cell battery, improves charging safety, and is beneficial to realizing high-power charging of 100W, 120W and above. In addition, in the trickle charge stage, the constant voltage charge stage and the charge cut-off stage of the three-cell battery 5, the boost circuit 1 is used for charging the three-cell battery 5, the control process is simple, the control flexibility is high, in the constant current charge stage of the three-cell battery 5, the first charge pump 3 is used for charging the three-cell battery 5, the output voltage of the first charge pump 3 is smaller than the input voltage of the first charge pump 3, the output current of the first charge pump 3 is larger than the input current of the first charge pump 3, the current transmitted on a charging wire rod can be reduced when large current charging is realized, the heating on the charging wire rod is further improved, meanwhile, the heating of a charging chip and a PCB can be reduced, namely, the overall heating of the charging circuit is reduced, and the high charging efficiency of the three-cell battery is ensured.

Fig. 2 is a schematic structural diagram of another charge and discharge control circuit of a three-cell battery according to an embodiment of the present disclosure. Different from the charge and discharge control circuit with the structure shown in fig. 1, the charge and discharge control circuit with the structure shown in fig. 2 includes a plurality of first charge pumps 3, an external power adapter 4 is electrically connected to the plurality of first charge pumps 3, the control circuit 2 is electrically connected to the plurality of first charge pumps 3, and a three-cell battery 5 is electrically connected to the plurality of first charge pumps 3. Specifically, when the charging voltage is the same, the charging current is larger, the charging power is higher, but the heat generation is more, and in order to ensure that the heat generation is reduced as much as possible while the larger charging power of the three-cell battery 5 is ensured, the charging power and the heat generation are balanced, and the applicable charging current range of the single first charge pump 3 may be 4A to 6A.

Therefore, the charge pump circuit suitable for large charging current is formed by arranging the charge and discharge control circuit to comprise the first charge pumps 3, and the first charge pumps 3 form a parallel connection relationship, that is, the number of the first charge pumps 3 connected in parallel can be selected according to the charging current of the three-cell battery 5 in practical application, and the larger the charging current of the three-cell battery 5 is, the larger the number of the first charge pumps 3 is, so that the power supply conversion efficiency of the charge and discharge control circuit is improved, and the heat generation is reduced. For example, when the charging current of the three-cell battery 5 is 8A to 10A, the charge and discharge control circuit may be configured to include two first charge pumps 3, and each first charge pump 3 shares the charging current of 4A to 5A; when the charging current of the three-cell battery 5 is 20A, the charge and discharge control circuit may be configured to include four first charge pumps 3, and each first charge pump 3 shares the charging current of 5A. It should be noted that, when the charging current of the three telecommunication batteries is other current values or other current ranges, the number of the first charge pumps 3 in the charge and discharge control circuit 2 may be adjusted accordingly, which is not specifically limited in the embodiment of the present disclosure.

Optionally, with reference to fig. 1 and fig. 2, the charge and discharge control circuit may further include a first voltage-reducing circuit 6 and a discharge circuit 7, where the first voltage-reducing circuit 6 is electrically connected to the external power adapter 4, the control circuit 2, and the system power supply module 8, the discharge circuit 7 is electrically connected to the control circuit 2, the three-cell battery 5, and the system power supply module 8 is configured to provide a relevant power supply for a system in the mobile terminal, so as to ensure that the terminal system can normally operate. The control circuit 2 is configured to control, according to setting parameters of the three-cell battery 5, on and off periods of the first voltage-reducing circuit 6 and the discharge circuit 7, where the first voltage-reducing circuit 6 is configured to supply power to the system power supply module 8 in a constant-current charging stage, a constant-voltage charging stage, and a charge ending stage of the three-cell battery 5, and the discharge circuit 7 is configured to supply power to the system power supply module 8 in a discharge stage of the three-cell battery 5.

Specifically, in the constant-current charging stage of the three-cell battery 5, when the control circuit 2 monitors that the charging voltage of the three-cell battery 5 is greater than the set voltage threshold and the charging current of the three-cell battery 5 is greater than the set current threshold, for example, 1A or 2A, the control circuit 2 controls the first voltage reduction circuit 6 to be turned on, and the first voltage reduction circuit 6 supplies power to the system power supply module 8, so that in the process of charging the three-cell battery 5, the first voltage reduction circuit 6 is used for supplying power to the system power supply module 8, the charging process of the three-cell battery 5 is not affected, the three-cell battery 5 can be effectively prevented from being charged and discharged, and the effective protection of the three-cell battery 5 is realized, and the process control circuit 2 controls the discharging circuit 7, the voltage boosting circuit 1 and the first charge pump 3 to be turned off. At this time, the setting parameters of the three-cell battery 5 include the charging voltage of the three-cell battery 5 and the charging current of the three-cell battery 5.

In the constant-voltage charging stage and the charging ending stage of the three-cell battery 5, when the control circuit 2 monitors that the charging current of the three-cell battery 5 is smaller than a set current threshold value, the control circuit 2 also controls the first voltage reduction circuit 6 to be opened, the first voltage reduction circuit 6 supplies power to the system power supply module 8, the charging process of the three-cell battery 5 is realized, the first voltage reduction circuit 6 is utilized to supply power to the system power supply module 8, the charging process of the three-cell battery 5 is not influenced, the three-cell battery 5 can be effectively prevented from being charged and discharged at the same time, the effective protection of the three-cell battery 5 is realized, the process control circuit 2 controls the discharging circuit 7, the boosting circuit 1 and the first charge pump 3 to be closed. At this time, the setting parameter of the three-cell battery 5 includes the charging current of the three-cell battery 5.

In the discharging stage of the three-cell battery 5, the control circuit 2 controls the discharging circuit 7 to be opened, the three-cell battery 5 discharges, the discharging circuit 7 performs voltage reduction processing on the output voltage of the three-cell battery 5 and then outputs the output voltage to the system power supply module 8 to supply power to the system power supply module 8, and the process control circuit 2 controls the first voltage reduction circuit 6, the voltage boost circuit 1 and the first charge pump 3 to be closed. Illustratively, the discharge circuit 7 may be arranged to include a second voltage reduction circuit or at least one second charge pump to implement the voltage reduction function of the discharge circuit 7. At this time, the setting parameter of the three-cell battery 5 includes that the three-cell battery 5 is in a discharge state.

Alternatively, the first charge pump 3 may be configured to include a plurality of first switches and N first capacitors, where the first switches are configured to control the series-parallel connection state of the first capacitors in the first charge pump 3 according to their own switch states, so that the output voltage of the first charge pump 3 is equal to 1/N of the input voltage of the first charge pump 3, and N is an integer greater than 1. The second charge pump comprises a plurality of second switches and M second capacitors, the second switches are used for controlling the series-parallel connection state of the second capacitors in the second charge pump according to the switch states of the second switches, so that the output voltage of the second charge pump is equal to 1/M of the input voltage of the second charge pump, and M is an integer greater than 1.

Specifically, the existing voltage-reducing circuit generally comprises an LC circuit, the LC circuit is composed of an inductor and a capacitor, the inductor has coil loss and magnetic core loss, and the voltage-reducing conversion efficiency of the whole voltage-reducing circuit is low, and the energy lost by the main power devices is basically converted into heat energy, so that the charging scheme of the voltage-reducing circuit generates heat seriously, and large-current charging cannot be realized. According to the embodiment of the disclosure, the first charge pump and the second charge pump are used for realizing voltage reduction, an inductor in a traditional voltage reduction circuit is omitted, power loss caused by the inductor is effectively avoided, the heat productivity in the charging process is reduced, the charging efficiency is effectively improved, and high-power charging is favorably realized.

Optionally, the first charge pump 3 alternatively operates in a first time period and a second time period, in the first time period, the first switch controls the first capacitors to form a series connection according to its own switch state, and in the second time period, the first switch controls the first capacitors to form a parallel connection according to its own switch state. The second charge pump works alternately in a third time interval and a fourth time interval, in the third time interval, the second switch controls the second capacitor to form a series connection relation according to the switch state of the second switch, and in the fourth time interval, the second switch controls the second capacitor to form a parallel connection relation according to the switch state of the second switch. Specifically, the voltage division characteristics of all the first capacitors may be set to be the same so as to form a series or parallel relationship at different time intervals through the first capacitors, respectively, and the output voltage of the first charge pump is equal to 1/N of the input voltage of the first charge pump, that is, the voltage reduction function of the first charge pump is realized. Likewise, the voltage division characteristics of all the second capacitors can be set to be the same to form a series or parallel relationship respectively at different periods through the second capacitors, so that the output voltage of the second charge pump is equal to 1/M of the input voltage of the second charge pump, namely, the voltage reduction function of the second charge pump is realized.

Taking the first charge pump 3 as an example and N is equal to 2 as an example, fig. 3 is a schematic structural diagram of the first charge pump according to an embodiment of the disclosure. As shown in fig. 3, the first charge pump 3 may be arranged to include two first capacitors C1, i.e. a first capacitor C11 and a first capacitor C12, i.e. N is equal to 2, i.e. the output voltage of the first charge pump 3 is equal to 1/2 of the input voltage of the first charge pump 3, and the output current of the first charge pump 3 is equal to about twice the input current of the first charge pump 3. The first charge pump 3 further includes four first switches K1, i.e., a first switch K11 to a first switch K14, and the specific connection relationship between the first capacitor C1 and the first switch K1 is shown in fig. 3 and will not be described herein. Illustratively, the first charge pump 3 may further include a filter capacitor C01, where the filter capacitor C01 is disposed corresponding to the input VIN of the first charge pump 3, so as to implement the function of filtering out noise. It should be noted that N here refers to the number of the first capacitors C1 that are indispensable in the first charge pump 3, and the filter capacitor C01 may be optional.

As shown in fig. 3, in the first period, the first switch K11 and the first switch K13 are controlled to be turned on, the first switch K12 and the first switch K14 are turned off, the first capacitor C11 and the first capacitor C12 form a series relationship, the first capacitor C11 and the first capacitor C12 are charged, and the voltage across the first capacitor C11 and the voltage across the first capacitor C12 are both approximately equal to 1/2 of the input voltage of the first charge pump 3. In the second period, the first switch K12 and the first switch K14 are controlled to be turned on, the first switch K11 and the first switch K13 are turned off, the first capacitor C11 and the first capacitor C12 form a parallel relationship, the first capacitor C11 and the first capacitor C12 are discharged, the output voltage of the first charge pump 3, namely the voltage on the first capacitor C12, is approximately equal to 1/2 of the input voltage of the first charge pump 3, so that the voltage reduction function of the first charge pump 3 is realized, and the output voltage of the first charge pump 3 is equal to 1/2 of the input voltage of the first charge pump 3.

Taking the first charge pump 3 as an example and N is equal to 3 as an example, fig. 4 is a schematic structural diagram of another first charge pump provided in the embodiment of the present disclosure. As shown in fig. 4, the first charge pump 3 may be arranged to include three first capacitors C1, i.e. a first capacitor C11, a first capacitor C12 and a first capacitor C13, i.e. N is equal to 3, i.e. the output voltage of the first charge pump 3 is equal to 1/3 of the input voltage of the first charge pump 3, and the output current of the first charge pump 3 is equal to about three times the input current of the first charge pump 3. The first charge pump 3 further includes seven first switches K1, i.e., a first switch K11 to a first switch K17, and the specific connection relationship between the first capacitor C1 and the first switch K1 is shown in fig. 4 and will not be described herein. Illustratively, the first charge pump 3 may further include a filter capacitor C02, and the filter capacitor C02 is disposed corresponding to the input terminal of the first charge pump 3, so as to implement the function of filtering out noise. It should be noted that N here refers to the number of the first capacitors C1 that are indispensable in the first charge pump 3, and the filter capacitor C02 may be optional.

As shown in fig. 4, in the first period, the first switch K11, the first switch K14 and the first switch K17 are controlled to be turned on, the remaining first switches K1 are turned off, the first capacitor C11, the first capacitor C12 and the first capacitor C13 form a series relationship, the first capacitor C11, the first capacitor C12 and the first capacitor C13 are charged, and the voltage across the first capacitor C11, the voltage across the first capacitor C12 and the voltage across the first capacitor C13 are all approximately equal to 1/3 of the input voltage of the first charge pump 3. In the second period, the first switch K12, the first switch K13, the first switch K15 and the first switch K16 are controlled to be turned on, the remaining first switches K1 are turned off, the first capacitor C11, the first capacitor C12 and the first capacitor C13 form a parallel relationship, the first capacitor C11, the first capacitor C12 and the first capacitor C13 are controlled to be turned off, the output voltage of the first charge pump 3, namely, the voltage on the first capacitor C13 is approximately equal to 1/3 of the input voltage of the first charge pump 3, so that the voltage reduction function of the first charge pump 3 is realized, and the output voltage of the first charge pump 3 is equal to 1/3 of the input voltage of the first charge pump 3.

It should be noted that the specific structure and the working principle of the second charge pump are similar to those of the first charge pump 3, and are not described herein again, and the voltage reduction multiples of the first charge pump 3 and the second charge pump may be the same or different. In addition, the above embodiment has been described only by taking the example that the voltage reduction factor of the first charge pump 3 is 1/2 and 1/3, and the voltage reduction factor of the first charge pump 3 may be 1/a, and a is an integer greater than 3.

Fig. 5 is a schematic structural diagram of a first voltage-reducing circuit according to an embodiment of the disclosure. As shown in fig. 5, the first step-down circuit 6 may include a third switch K3, a fourth switch K4, and a first inductor L1, the third switch K3 is connected in series between the input terminal VIN of the first step-down circuit 6 and the first terminal of the first inductor L1, the fourth switch K4 is connected in series between a first node N1 and the ground terminal GND, the second terminal of the first inductor L1 is used as the output terminal VOUT of the first step-down circuit 6, and the first node N1 is a series node of the third switch K3 and the first inductor L1. The second voltage reduction circuit comprises a fifth switch, a sixth switch and a second inductor, the fifth switch is connected between the input end of the second voltage reduction circuit and the first end of the second inductor in series, the sixth switch is connected between a second node and the grounding end in series, the second end of the second inductor is used as the output end of the second voltage reduction circuit, and the second node is a series connection node of the fifth switch and the second inductor.

Taking the first voltage-reducing circuit 6 as an example, with reference to fig. 1, fig. 2 and fig. 5, the first voltage-reducing circuit 6 includes two working phases, the first working phase is a charging phase of the first inductor L1, the first working phase controls the third switch K3 to be turned on, the fourth switch K4 to be turned off, the first inductor L1 charges, the third switch K3, the first inductor L1 and the system power supply module 8 form a main loop, and a main current of the circuit flows through the third switch K3, the first inductor L1 and the system power supply module 8. The second working stage is a discharging stage of the first inductor L1, the discharging stage controls the third switch K3 to be turned off, the fourth switch K4 to be turned on, the first inductor L1 discharges, the fourth switch K4, the first inductor L1 and the system power supply module 8 form a main loop, and a main current of the circuit flows through the fourth switch K4, the first inductor L1 and the system power supply module 8. Illustratively, the first voltage-reducing circuit 6 may further include a filter capacitor C03 and a filter capacitor C04, the filter capacitor C03 is disposed corresponding to the input terminal VIN of the first voltage-reducing circuit 6, and the filter capacitor C04 is disposed corresponding to the output terminal VOUT of the first voltage-reducing circuit 6, so as to implement a function of filtering out noise.

The first voltage reduction circuit 6 and the second voltage reduction circuit are arranged only for supplying power to the system power supply module 8, and the three-cell battery 5 is not charged, so that the problem of excessive heat generation in the large-current charging process is avoided, and the charging efficiency is further improved. It should be noted that the specific structure and the operation principle of the second voltage-reducing circuit are similar to those of the first voltage-reducing circuit 6, and are not described herein again.

Fig. 6 is a schematic structural diagram of a voltage boost circuit according to an embodiment of the present disclosure. As shown in fig. 6, it may be provided that the voltage boost circuit 1 includes a seventh switch K7, an eighth switch K8 and a third inductor L3, the seventh switch K7 is connected in series between the first end of the third inductor L3 and the output end of the voltage boost circuit 1, the eighth switch K8 is connected in series between the third node N3 and the ground end, and the second end of the third inductor L3 is used as the input end of the voltage boost circuit 1; the third node N3 is a series node of the seventh switch K7 and the third inductor L3.

Specifically, with reference to fig. 1, fig. 2 and fig. 6, the voltage boost circuit 1 includes two operation phases, the first operation phase is a charging phase of the third inductor L3, the first operation phase controls the eighth switch K8 to be turned on, the seventh switch K7 to be turned off, the third inductor L3 is charged, the eighth switch K8 and the third inductor L3 form a main loop, and a main current of the circuit flows through the eighth switch K8 and the third inductor L3. The second working phase is a discharging phase of the third inductor L3, the discharging phase controls the eighth switch K8 to be turned off, the seventh switch K7 to be turned on, the third inductor L3 to be discharged, the seventh switch K7, the third inductor L3 and the three-cell battery 5 form a main circuit, and a main current of the circuit flows through the seventh switch K7, the third inductor L3 and the three-cell battery 5.

For example, the switch mentioned in the above embodiments may include a Metal-Oxide-Semiconductor Field-Effect Transistor (MOSFET) or other switch transistors known to those skilled in the art, and the embodiment of the present disclosure is not limited thereto.

The embodiment of the present disclosure further provides a charge and discharge control method for a three-cell battery, which is executed by the charge and discharge control circuit for a three-cell battery according to the embodiment, and fig. 7 is a schematic flow diagram of the charge and discharge control method for a three-cell battery according to the embodiment of the present disclosure. As shown in fig. 7, the charge and discharge control method of the three-cell battery includes:

and S110, acquiring the setting parameters of the external power adapter and the setting parameters of the three-cell battery.

According to the description of the above embodiment, the setting parameters of the external power adapter may include a port type of the external power adapter, and the setting parameters of the three-cell battery may include a voltage of the three-cell battery, a charging voltage of the three-cell battery, and a charging current of the three-cell battery.

And S120, judging the working stage of the three-cell battery according to the set parameters of the external power adapter and the set parameters of the three-cell battery.

Specifically, it is determined which stage the three-cell battery is in the trickle charge stage, the constant voltage charge stage, and the charge termination stage, according to the setting parameter of the external power adapter and the setting parameter of the three-cell battery.

And S130, controlling the boosting circuit to charge the three-cell battery in a trickle charge stage, a constant-voltage charge stage and a charge cut-off stage.

And S140, in the constant current charging stage, controlling the first charge pump to charge the three-cell battery.

Optionally, with reference to fig. 1 and fig. 2, the charge and discharge control circuit further includes a first voltage-reducing circuit 6 and a discharge circuit 7, the first voltage-reducing circuit 6 is electrically connected to the external power adapter 4, the control circuit 2, and the system power supply module 8, and the discharge circuit 7 is electrically connected to the control circuit 2, the three-cell battery 5, and the system power supply module 8. The charge and discharge control method of the three-cell battery 5 further comprises the steps of controlling the first voltage reduction circuit 6 to supply power to the system power supply module 8 in a constant current charging stage, a constant voltage charging stage and a charging ending stage, and controlling the discharge circuit 7 to supply power to the system power supply module 8 in a discharging stage. Therefore, the charging process of the three-cell battery 5 is not influenced, the three-cell battery 5 can be effectively prevented from discharging while charging, and the three-cell battery 5 is effectively protected.

The embodiment of the present disclosure further provides a terminal device, where the terminal device includes a three-cell battery and the charge and discharge control circuit of the three-cell battery as described in the above embodiment, and therefore the terminal device has the beneficial effects described in the above embodiment, and details are not repeated here. Illustratively, the terminal device may be a mobile phone, a tablet, a mobile computer or other rechargeable terminal devices known to those skilled in the art, which is not limited by the embodiments of the present disclosure. In addition, above-mentioned three electric core battery's charge and discharge control circuit also can integrate in terminal equipment's charging wire, can flow through undercurrent on most wire rods of charging wire to reduce the generating heat on the wire rod, slow down the loss of wire rod.

It is to be noted that the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other identical elements in a process, method, article, or apparatus that comprises the element.

The foregoing are merely exemplary embodiments of the present disclosure, which enable those skilled in the art to understand or practice the present disclosure. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the disclosure. Thus, the present disclosure is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A charge and discharge control circuit of a three-cell battery is characterized by comprising:

2. The charge and discharge control circuit of a three-cell battery according to claim 1, further comprising:

3. The charge and discharge control circuit of a three-cell battery of claim 2, wherein the discharge circuit comprises a second voltage reduction circuit or at least one second charge pump.

4. The charge and discharge control circuit of the three-cell battery according to claim 3, wherein the first charge pump comprises a plurality of first switches and N first capacitors, and the first switches are configured to control series-parallel connection states of the first capacitors in the first charge pump according to their own switch states so that an output voltage of the first charge pump is equal to 1/N of an input voltage of the first charge pump; wherein N is an integer greater than 1;

5. The charge and discharge control circuit of a three-cell battery according to claim 4, wherein the first charge pump is operated alternately for a first period of time and a second period of time;

the second charge pump works in a third period and a fourth period alternately;

6. The charge and discharge control circuit for the three-cell battery according to claim 3, wherein the first voltage-reducing circuit comprises a third switch, a fourth switch and a first inductor, the third switch is connected in series between the input end of the first voltage-reducing circuit and the first end of the first inductor, the fourth switch is connected in series between a first node and a ground terminal, and the second end of the first inductor serves as the output end of the first voltage-reducing circuit; wherein the first node is a series node of the third switch and the first inductor;

7. The charge and discharge control circuit of a three-cell battery according to claim 1, wherein the boost circuit comprises:

8. A charge and discharge control method for a three-cell battery, which is performed by the charge and discharge control circuit for a three-cell battery according to any one of claims 1 to 7, the charge and discharge control method for a three-cell battery comprising:

9. The method according to claim 8, wherein the charge-discharge control circuit further includes a first voltage-reducing circuit and a discharge circuit, the first voltage-reducing circuit is electrically connected to the external power adapter, the control circuit, and the system power supply module, and the discharge circuit is electrically connected to the control circuit, the three-cell battery, and the system power supply module, respectively;

10. A terminal device characterized by comprising a three-cell battery and a charge and discharge control circuit for the three-cell battery according to any one of claims 1 to 7.