CN113824196B

CN113824196B - Battery charging circuit, device and terminal equipment

Info

Publication number: CN113824196B
Application number: CN202111383938.2A
Authority: CN
Inventors: 刘锐
Original assignee: Guangdong Xidi Microelectronics Co ltd
Current assignee: Xidi Microelectronics Group Co ltd
Priority date: 2021-11-19
Filing date: 2021-11-19
Publication date: 2022-03-11
Anticipated expiration: 2041-11-19
Also published as: CN113824196A

Abstract

The invention relates to the field of battery charging, in particular to a battery charging circuit, a device and terminal equipment, wherein the battery charging circuit comprises: a second switch unit having a third lead-out terminal and a fourth lead-out terminal; a switching converter having a first input lead-out terminal and a first output lead-out terminal; a switched capacitor converter having a second input lead-out terminal and a second output lead-out terminal; a first switch unit having a first lead-out terminal and a second lead-out terminal; each lead-out terminal has at least one first connection mode in which the battery charging circuit is configured to supply power to a single battery and at least one second connection mode in which the battery charging circuit is configured to supply power to a double battery. Compared with the prior art, the battery charging circuit has good universality, and can be suitable for single batteries and double batteries.

Description

Battery charging circuit, device and terminal equipment

Technical Field

The present invention relates to the field of battery charging, and in particular, to a battery charging circuit, a battery charging device, and a terminal device.

Background

Terminal equipment such as smart mobile phones generally use a single battery or two batteries connected in parallel or in series to supply power to the battery, and generally, the single battery needs to be adapted to a charging circuit of the single battery, the two batteries need to be adapted to a charging circuit of the two batteries, and the universality of the charging circuit is poor.

Disclosure of Invention

The invention provides a battery charging circuit, a device and terminal equipment, wherein the battery charging circuit can be suitable for single batteries and double batteries, and has good universality.

In a first aspect, the present invention provides a battery charging circuit comprising:

a switching converter having a first input lead terminal and a first output lead terminal, the switching converter configured to operate in a boost mode or a buck mode;

a switched-capacitor converter having a second input terminal and a second output terminal, the switched-capacitor converter configured to operate in a fixed-rate boost charge pump mode or a fixed-rate buck charge pump mode;

a first switching unit having a first lead-out terminal and a second lead-out terminal, the first switching unit being configured to turn on or off a connection of the first lead-out terminal and the second lead-out terminal;

each lead-out terminal has at least one first connection mode in which the battery charging circuit is configured to supply power to a single battery and at least one second connection mode in which the battery charging circuit is configured to supply power to a double battery.

Optionally, the second switch unit has a third outgoing terminal and a fourth outgoing terminal, and the second switch unit is configured to turn on or off the connection between the third outgoing terminal and the fourth outgoing terminal.

Optionally, the first switch unit includes a first switch, and the second switch unit includes a second switch;

the first input leading-out terminal is connected with the input end of the switch converter, the first output leading-out terminal is connected with the output end of the switch converter, the second input leading-out terminal is connected with the input end of the switch capacitor converter, and the second output leading-out terminal is connected with the output end of the switch capacitor converter;

the first leading-out terminal is connected with a first end of the first switch, the second leading-out terminal is connected with a second end of the first switch, the third leading-out terminal is connected with a first end of the second switch, and the fourth leading-out terminal is connected with a second end of the second switch.

Optionally, the method further includes:

a third switching unit having a fifth lead-out terminal, the third switching unit including a third switch;

a first end of the third switch is connected to the output end of the switching converter, a second end of the third switch is connected to the fifth outgoing terminal, and the third switch is configured to turn on or off the connection between the output end of the switching converter and the fifth outgoing terminal.

Optionally, one of the first connection modes is:

the third leading-out terminal is used for connecting a power supply, the fourth leading-out terminal is connected with the first input leading-out terminal, the first output leading-out terminal is used for connecting a load, the fifth leading-out terminal is connected with the second output leading-out terminal and the single battery, the second input leading-out terminal is connected with the second leading-out terminal, and the first leading-out terminal is connected with the third leading-out terminal or the fourth leading-out terminal.

Optionally, the first connection mode is:

the third leading-out terminal is used for connecting a power supply, the fourth leading-out terminal is connected with the first input leading-out terminal, the first output leading-out terminal is connected with the second output leading-out terminal and is used for connecting a load, the second input leading-out terminal is connected with the first leading-out terminal, and the second leading-out terminal is used for connecting the double batteries.

Optionally, the second connection mode is:

the third leading-out terminal is used for connecting a power supply, the fourth leading-out terminal is connected with the first output leading-out terminal, the first input leading-out terminal is connected with the first leading-out terminal and the second input leading-out terminal, the second output leading-out terminal is used for connecting a load, and the second leading-out terminal is used for connecting the double batteries.

Optionally, the fifth outgoing terminal is further used for connecting the load.

Optionally, the fourth connection mode is:

the third leading-out terminal is used for connecting a power supply, the fourth leading-out terminal is connected with the first input leading-out terminal, the first output leading-out terminal is used for connecting a load and the first leading-out terminal, the second leading-out terminal is connected with the second output leading-out terminal, and the second input leading-out terminal is used for connecting the double batteries.

Optionally, the switch converter is integrated in a first device, and the switched capacitor converter and the first switching unit are integrated in a second device;

alternatively, the switching converter, the switched capacitor converter and the first switching unit are integrated in a third device.

Optionally, when the switching converter, the switched capacitor converter and the first switching unit are integrated in a third device, the switching converter is located in a first layout area, and the first switching unit and the switched capacitor converter are located in a second layout area; alternatively, the first and second electrodes may be,

the switching converter, the switched capacitor converter and the first switching unit are located in a third layout area.

Optionally, the switching converter includes:

a fourth switch and a fifth switch connected in series between the input terminal of the switching converter and ground;

and a first end of the inductor is connected with a common node of the fourth switch and the fifth switch, and a second end of the inductor is connected with an output end of the switching converter.

Optionally, the switched capacitor converter includes:

a sixth switch, a seventh switch, an eighth switch, and a ninth switch connected in series between the input terminal of the switched capacitor converter and ground;

and a tenth switch, an eleventh switch, a twelfth switch, and a thirteenth switch connected in series between the input of the switched-capacitor converter and ground;

the switched capacitor converter further comprises a sixth leading-out terminal, a seventh leading-out terminal, an eighth leading-out terminal and a ninth leading-out terminal;

the sixth leading terminal is connected to a common node of the sixth switch and the seventh switch, the seventh leading terminal is connected to a common node of the eighth switch and the ninth switch, the eighth leading terminal is connected to a common node of the tenth switch and the eleventh switch, and the ninth leading terminal is connected to a common node of the twelfth switch and the thirteenth switch;

the sixth leading-out terminal is used for connecting a first end of a first flying capacitor, the seventh leading-out terminal is used for connecting a second end of the first flying capacitor, the eighth leading-out terminal is used for connecting a first end of a second flying capacitor, and the ninth leading-out terminal is used for connecting a second end of the second flying capacitor.

In a second aspect, the present invention provides a battery charging apparatus comprising: in the above battery charging circuit, the connection of each lead-out terminal is configured to be in the first connection mode or the second connection mode, and when the battery charging device is used for supplying power to a single battery, the connection of each lead-out terminal is configured to be in the first connection mode, and when the battery charging device is used for supplying power to a double battery, the connection of each lead-out terminal is configured to be in the second connection mode.

In a third aspect, the present invention provides a terminal device, where the terminal device includes the above battery charging apparatus and a battery, and the battery is a single battery or a double battery.

Compared with the prior art, the battery charging circuit divides a plurality of components for charging the battery into a plurality of modules, and the leading-out terminals are arranged, so that the leading-out terminals can be connected according to different connection modes based on the number of the batteries needing power supply, for example, when the battery is a single battery, the leading-out terminals are connected according to a first connection mode, and when the battery is a double battery, the leading-out terminals are connected according to a second connection mode. Therefore, the battery charging circuit has good universality, and can be suitable for single batteries and double batteries.

Drawings

Fig. 1 is a schematic structural diagram of a terminal device;

FIG. 2 is a block diagram of the structure of one embodiment of a battery charging apparatus;

FIG. 3 is a schematic circuit diagram of one embodiment of a battery charging apparatus;

FIG. 4 is a schematic diagram of the circuit configuration of one embodiment of a battery charging apparatus;

FIG. 5a is a schematic diagram of a circuit configuration of an embodiment of a battery charging circuit

FIG. 5b is a schematic diagram of the circuit configuration of one embodiment of a battery charging circuit;

FIG. 5c is a schematic diagram of the circuit configuration of one embodiment of a battery charging circuit;

FIG. 5d is a schematic diagram of the circuit configuration of one embodiment of a battery charging circuit;

FIG. 6 is a schematic circuit diagram of one embodiment of a battery charging apparatus;

FIG. 7 is a schematic diagram of the circuit configuration of one embodiment of a battery charging apparatus;

FIG. 8 is a schematic circuit diagram of one embodiment of a battery charging apparatus;

FIG. 9 is a schematic diagram of the circuit configuration of one embodiment of a battery charging apparatus;

FIG. 10 is a schematic diagram of the circuit configuration of one embodiment of a battery charging apparatus;

FIG. 11 is a circuit configuration schematic of one embodiment of a battery charging circuit;

FIG. 12 is a schematic circuit diagram of one embodiment of a battery charging apparatus;

FIG. 13 is a schematic circuit diagram of one embodiment of a battery charging apparatus;

FIG. 14 is a schematic circuit diagram of one embodiment of a battery charging apparatus;

fig. 15 is a schematic circuit diagram of an embodiment of a battery charging apparatus.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention. All other embodiments, which can be obtained by a person skilled in the art without inventive effort based on the embodiments of the present invention, are within the scope of the present invention.

It should be noted that, if not conflicted, the various features of the embodiments of the invention may be combined with each other within the scope of protection of the invention. Additionally, while functional block divisions are performed in apparatus schematics, with logical sequences shown in flowcharts, in some cases, steps shown or described may be performed in sequences other than block divisions in apparatus or flowcharts. The terms "first", "second", "third", and the like used in the present invention do not limit data and execution order, but distinguish the same items or similar items having substantially the same function and action.

One or more embodiments are illustrated by way of example in the accompanying drawings, which correspond to the figures in which like reference numerals refer to similar elements and which are not to scale unless otherwise specified.

The terminal device usually uses a battery to supply power to each system load in the terminal device, and in some models of the terminal device, the running time is required to be long enough.

Fig. 1 shows a structure of a terminal device 1000, and in this embodiment, only a power supply structure of the terminal device 1000 is exemplarily shown, and other functional devices are not shown. As shown in fig. 1, the terminal device 1000 takes power from an external power source through the battery charging apparatus 100 and charges the battery 200.

Fig. 2 shows a structure of a battery charging apparatus, and as shown in fig. 2, the battery charging apparatus 100 has a VIN terminal, a VBAT terminal, and a VSYS terminal. The VIN terminal is coupled to an external power source, the VBAT terminal is coupled to a battery, and the VSYS terminal is coupled to a plurality of loads in the terminal device. The battery charging apparatus 100 converts or processes an external power to charge the battery 200 and supply power to the load 300.

The terminal devices include smart phones, tablet computers, PCs, digital cameras, MP3 players, and the like. The battery 200 may be a single battery, or alternatively, a double battery connected in series or in parallel.

The battery charging device can adopt the matching work of the switch converter and the switch capacitor converter to charge the battery and supply power for the load, and is provided with a plurality of switch units to control the charging process.

Because the charging voltage requirements of a single battery and a double battery are different, the battery charging devices that supply power to both are not constructed identically. Therefore, a battery charging device suitable for a single battery is not generally suitable for supplying power to two batteries, and the versatility of the battery charging device is poor.

Fig. 3 shows the structure of a battery charging apparatus for supplying power to a single battery, and as shown in fig. 3, the battery charging apparatus 100 includes two power stages connected in parallel. The first power stage is a switching converter 10 and the second power stage is a switched capacitor converter 20.

In this embodiment, the switching converter 10 is implemented as a buck switching converter. The switching converter 10 comprises a fourth switch 12 and a fifth switch 13 connected in series between the input voltage bus 101 and ground, and an inductor 14 is connected between a common node of the fourth switch 12 and the fifth switch 13 and the output voltage bus VSYS.

The input voltage bus 101 is coupled to an external power source VIN through a second switch 31, the second switch 31 is used for connecting or disconnecting the switching converter 10 and the external power source, and the second switch 31 is also used for providing reverse protection. A capacitor C3 is coupled between terminal VIN and ground, and a capacitor C5 is coupled between the output voltage bus VSYS and ground.

The output voltage bus VSYS is coupled to the individual batteries through a third switch 52, which third switch 52 is used to turn on or off the individual batteries to the switching converter 10. The third switch 52 is an isolation switch unit for providing isolation between the battery and the output voltage bus VSYS.

The switching unit charging controller 11 is configured to generate gate drive signals for the second switch 31, the fourth switch 12, and the fifth switch 13. The power path controller 51 is configured to generate a gate drive signal for the third switch 52.

In the present embodiment, the switched capacitor converter 20 is implemented as a two-phase switched capacitor converter, the first phase includes a sixth switch 22, a seventh switch 23, an eighth switch 24 and a ninth switch 25 connected in series between the voltage bus 102 and ground, and the first flying capacitor C1 is connected between a common node of the sixth switch 22 and the seventh switch 23 and a common node of the eighth switch 24 and the ninth switch 25. The common node of the seventh switch 23 and the eighth switch 24 is connected to a single battery and capacitor C7 via a voltage bus VBAT.

The second phase includes a tenth switch 26, an eleventh switch 27, a twelfth switch 28, and a thirteenth switch 29 connected in series between the voltage bus 102 and ground. A second flying capacitor C2 is connected between the common node of the tenth switch 26 and the eleventh switch 27 and the common node of the twelfth switch 28 and the thirteenth switch 29. The common node of the eleventh switch 27 and the twelfth switch 28 is connected to a single battery and capacitor C7 through a voltage bus VBAT.

The capacitor C4 is coupled between the voltage bus 102 and ground, and the voltage bus 102 is coupled to the external power source VIN through the first switch 42 and the second switch 31.

The switched-capacitor charging unit controller 21 is configured to generate gate drive signals for a sixth switch 22, a seventh switch 23, an eighth switch 24, a ninth switch 25, a tenth switch 26, an eleventh switch 27, a twelfth switch 28, and a thirteenth switch 29. The mode controller 41 is configured to generate a gate drive signal for the first switch 42.

The circuit configuration shown in fig. 3, the switching converter 10 and the switched capacitor converter 20, both of which can supply power to the battery and the load, is generally used to supply power to the battery 200 during the constant current charging mode and the front stage of the constant voltage charging mode due to the higher efficiency of the switched capacitor converter 20, and the switching converter 10 is generally used to supply power to the battery 200 during the pre-charging mode and the rear stage of the constant voltage charging mode due to the precise voltage control thereof.

In this embodiment, the switching converter 10 operates in a buck mode when supplying power to the battery and the load. According to various designs, the switching converter 10 may also operate in a reverse boost mode, with the VIN terminal powered from the battery.

The voltage on voltage bus VBAT is equal to one-half of the voltage on voltage bus 102 (i.e., the input voltage of switched capacitor converter 20). The switching cell capacitive conversion 20 can operate in either a 2:1 charge pump mode or a 1:2 charge pump mode. When fast charging of a single battery is required, the switched capacitor converter 20 is configured to operate in a 2:1 charge pump mode. When it is desired to boost the voltage on the voltage bus 102, the switched capacitor converter 20 can operate in a 1:2 charge pump mode where the voltage on the voltage bus 102 is equal to twice the battery voltage. It should be noted that in single battery charging, the 1:2 charge pump mode is disabled.

Fig. 4 shows a structure of a battery charging apparatus for supplying power to two batteries, and as shown in fig. 4, the battery charging apparatus 100 includes a first power stage and a second power stage, which are a switching converter 10 and a switching capacitor converter 20, respectively, connected in series.

The input voltage bus 101 is coupled to an external power source VIN through a second switch 31, the second switch 31 is used for connecting or disconnecting the switching converter 10 and the external power source, and the second switch 31 is also used for providing current limiting protection. A capacitor C3 is coupled between terminal VIN and ground, a capacitor C5 is connected between the output voltage bus VSYS and ground, and a capacitor C4 is coupled between the input voltage bus 101 and ground. The voltage bus BAT is coupled to the output voltage bus VSYS through a third switch 52, the third switch 52 being an isolating switch unit for providing isolation between the voltage bus BAT and the output voltage bus VSYS.

In the present embodiment, the switched-capacitor converter 20 is implemented as a two-phase switched-capacitor converter, the first phase includes a sixth switch 22, a seventh switch 23, an eighth switch 24, and a ninth switch 25 connected in series between the voltage bus VBAT and ground, and the first flying capacitor C1 is connected between a common node of the sixth switch 22 and the seventh switch 23 and a common node of the eighth switch 24 and the ninth switch 25. The common node of the seventh switch 23 and the eighth switch 24 is connected to an output capacitor C7 via a voltage bus BAT.

The second phase includes a tenth switch 26, an eleventh switch 27, a twelfth switch 28, and a thirteenth switch 29 connected in series between the voltage bus line VBAT and ground. A second flying capacitor C2 is connected between the common node of the tenth switch 26 and the eleventh switch 27 and the common node of the twelfth switch 28 and the thirteenth switch 29. The common node of the eleventh switch 27 and the twelfth switch 28 is connected to an output capacitor C7 via a voltage bus VBAT. Capacitor C6 is also coupled between voltage bus VBAT, which also connects the dual battery, and ground.

The switching unit capacitance charging controller 21 is configured to generate gate drive signals for a sixth switch 22, a seventh switch 23, an eighth switch 24, a ninth switch 25, a tenth switch 26, an eleventh switch 27, a twelfth switch 28, and a thirteenth switch 29.

In the embodiment shown in fig. 4, the switching converter 10 operates in a buck mode and the switched capacitor converter operates in a 1:2 charge pump mode. When an input voltage is provided at the external power VIN terminal, the switching converter 10 receives the input voltage, converts the input voltage, and outputs the converted input voltage to the output voltage bus VSYS and the voltage bus BAT. The output (which is the actual input) of the switched-capacitor converter 20 receives the voltage from the voltage bus BAT, converts it, and charges the dual battery via the voltage bus VBAT.

In this embodiment, the output of the switching converter 10 (VSYS and BAT) is adjusted, and then the voltage on BAT is doubled by the switching unit capacitance converter 20 to VBAT to reach the desired charging voltage of the dual battery.

As can be seen from fig. 3 and 4, when power is supplied to the single battery and the double battery, the structures of the battery charging apparatuses are different, and the battery charging apparatus applied to the single battery is not applied to power supply to the double battery, and the versatility of the battery charging apparatus is poor.

In order to solve the problem of poor universality of the battery charging device, embodiments of the present invention provide a battery charging circuit, in which a plurality of components are modularized and lead-out terminals are provided, so that the battery charging device can be obtained by connecting the lead-out terminals according to different connection modes based on the number of batteries to be powered, and the battery charging device can adapt to both single-battery power supply and double-battery power supply.

Fig. 5a shows a configuration of a battery charging circuit, which, as shown in fig. 5a, comprises a switched converter 10, a switched capacitor converter 20 and a first switching unit 40. Wherein the first switching unit 40 is provided with a first lead-out terminal T1 and a second lead-out terminal T2, respectively. The switching converter 10 is provided with a first input lead terminal I1 and a first output lead terminal O1, respectively, and the switched capacitor converter 20 is provided with a second input lead terminal I2 and a second output lead terminal O2, respectively.

The switching converter 10 may be any suitable voltage converter, such as a buck converter, configured to operate in either a boost mode or a buck mode. Fig. 5a shows a structure of the switching converter 10, in the embodiment shown in fig. 5a, the switching converter 10 includes a fourth switch 12 and a fifth switch 13 connected in series, a first terminal of the fourth switch 12 is an input terminal of the switching converter, a second terminal of the fourth switch 12 is connected to a first terminal of the fifth switch 13, a second terminal of the fifth switch 13 is grounded, a first terminal of an inductor 14 is connected to a common node of the fourth switch 12 and the fifth switch 13, and a second terminal of the inductor 14 is an output terminal of the switching converter 10.

The first input outgoing terminal I1 and the first output outgoing terminal O1 may be outgoing terminals that are connected to the input terminal and the output terminal of the switching converter 10, respectively, or may be two connection pins of the input terminal and the output terminal when the switching converter 10 is disposed on a PCB.

It should be noted that the input terminal of the switching converter refers to a common input terminal of the switching converter, and the output terminal of the switching converter refers to a common output terminal of the switching converter. For example, when the switching converter is a buck converter as shown in fig. 5a, the input terminal of the switching converter refers to the input terminal of the switching converter when the switching converter operates in the buck mode, and the output terminal of the switching converter refers to the output terminal of the switching converter when the switching converter operates in the buck mode. When the switching converter operates in the boost mode and the switching converter operates in the reverse mode, the input terminal of the switching converter refers to the actual output terminal of the switching converter, and the output terminal of the switching converter refers to the actual input terminal of the switching converter.

The switched-capacitor converter 20 may be a voltage converter with a fixed buck rate, such as a charge pump converter, and may be configured to operate in a fixed-rate buck charge pump mode or a fixed-rate boost charge pump mode, such as a 2:1 charge pump mode or a 1:2 charge pump mode.

Fig. 5a shows a structure of the switched capacitor converter 20, in the embodiment shown in fig. 5a, the switched capacitor converter 20 is implemented as a two-phase switched capacitor converter, the first phase comprises a sixth switch 22, a seventh switch 23, an eighth switch 24 and a ninth switch 25 connected in series, and the first flying capacitor C1 is connected between a common node of the sixth switch 22 and the seventh switch 23 and a common node of the eighth switch 24 and the ninth switch 25.

The second phase comprises a tenth switch 26, an eleventh switch 27, a twelfth switch 28 and a thirteenth switch 29 connected in series. A second flying capacitor C2 is connected between the common node of the tenth switch 26 and the eleventh switch 27 and the common node of the twelfth switch 28 and the thirteenth switch 29.

A common node of the sixth switch 22 and the tenth switch 26 is an input terminal, and a common node of the seventh switch 23 and the eighth switch 24, and a common node of the eleventh switch 27 and the twelfth switch 28 are output terminals.

The second input outgoing terminal I2 and the second output outgoing terminal O2 may be outgoing terminals that are connected to the input terminal and the output terminal of the switched capacitor converter 20, respectively, or may be two connection pins of the input terminal and the output terminal when the switched capacitor converter 20 is disposed on a PCB.

It should be noted that the input terminal of the switched capacitor converter refers to a common input terminal of the switched capacitor converter, and the output terminal of the switched capacitor converter refers to a common output terminal of the switched capacitor converter. For example, when the switched capacitor converter is a charge pump converter with a step-down ratio of 2:1 as shown in fig. 5a, the input terminal of the switched capacitor converter refers to the input terminal of the switched capacitor converter operating in the 2:1 charge pump mode, and the output terminal of the switched capacitor converter refers to the output terminal of the switched capacitor converter operating in the 2:1 charge pump mode. When the switched capacitor converter works in the 1:2 charge pump mode, the switched capacitor converter works in the reverse mode, the input end of the switched capacitor converter refers to the actual output end of the switched capacitor converter, and the output end of the switched capacitor converter refers to the actual input end of the switched capacitor converter.

And a first switch unit 40 having a first lead-out terminal T1 and a second lead-out terminal T2, the first switch unit 40 being for turning on or off the connection of the first lead-out terminal T1 and the second lead-out terminal T2. In some embodiments, the first switch unit 40 includes the first switch 42, and the first outgoing terminal T1 and the second outgoing terminal T2 may be outgoing terminals respectively connected to two ends of the first switch 42, or two connection pins of the first switch 42 when the first switch 42 is disposed on a PCB.

The first switch 42 may also be configured to operate in a saturated conduction mode to limit the dc current flowing from the first outgoing terminal T1 to the second outgoing terminal T2 and to provide a voltage difference between the first outgoing terminal T1 and the second outgoing terminal T2 required by the system.

In other embodiments, referring to fig. 5b, the battery charging circuit further includes a second switch unit 30, and the second switch unit 30 is respectively provided with a third outgoing terminal T3 and a fourth outgoing terminal T4. The second switch unit 30 is configured to turn on or off the connection between the third outgoing terminal T3 and the fourth outgoing terminal T4, and the second switch unit 30 is configured to connect to an external power source, which may be specifically connected to the external power source through the third outgoing terminal T3 or the fourth outgoing terminal T4. For example, an external power source is connected through the third lead terminal T3, and when the second switching unit 30 is turned on, the power source is also connected to the fourth lead terminal T4, so that the power source can be connected to the lower circuit through the fourth lead terminal T4.

In some embodiments, the second switch unit 30 includes the second switch 31, and the third outgoing terminal T3 and the fourth outgoing terminal T4 may be outgoing terminals respectively connected to two ends of the second switch 31, or the third outgoing terminal T3 and the fourth outgoing terminal T4 may also be two connection pins of the second switch 31 when the second switch 31 is disposed on a PCB.

In other embodiments, referring to fig. 5c, the battery charging circuit further includes a third switching unit 50, the third switching unit 50 has a fifth outgoing terminal T5, and the third switching unit 50 includes a third switch 52. A first end of the third switch 52 is connected to the output terminal of the switching converter 10 (i.e., to the first output terminal), and a second end of the third switch 52 is connected to the fifth terminal. The third switch is used to turn on or off the connection of the output terminal of the switching converter 10 and the fifth outgoing terminal T5. The fifth outgoing terminal T5 may be an outgoing terminal connected to the second end of the third switch, or may be a connection pin corresponding to the second end of the third switch when the third switch is disposed on the PCB.

The third switch 52 may also be configured to operate in a saturated conduction mode to achieve current limiting of the dc current flowing from the first output terminal O1 to the fifth terminal T5 of the switching converter 10, while providing the voltage difference between the first output terminal O1 and the fifth terminal T5 required by the system.

Fig. 5a and 5b, and fig. 5c and 5d differ in that the second switching unit 30 is not provided in fig. 5 a. Fig. 5c differs from fig. 5a and 5b in that, in fig. 5c, the switching converter 10 may be connected to the lower circuit through the fifth lead-out terminal T5 of the third switching unit 50 in addition to the connection of the lower circuit through the first output lead-out terminal O1. The output of the switching converter 10 and the lower stage circuit may be isolated by the third switching unit 50. For example, in the embodiment shown in fig. 3, the third switch 52 may be implemented as an isolation switch to provide isolation between the voltage bus BAT and the output voltage bus VSYS.

In the embodiment shown in fig. 5a, 5b and 5C, first flying capacitor C1 and second flying capacitor C2 are integrated within switched capacitor converter 20. In other embodiments, in the modularization of the battery charging circuit, instead of integrating the capacitor in the switched capacitor converter 20, the leading terminals may be provided for the first flying capacitor and the second flying capacitor. In specific application, the first flying capacitor and the second flying capacitor are connected to the leading-out terminal according to the power supply requirement of a single battery or a double battery.

Referring to fig. 5d, the switched capacitor converter 20 further includes a sixth outgoing terminal T6, a seventh outgoing terminal T7, an eighth outgoing terminal T8, and a ninth outgoing terminal T9. The sixth outgoing terminal T6 is connected to a common node of the sixth switch 22 and the seventh switch 23, the seventh outgoing terminal T7 is connected to a common node of the eighth switch 24 and the ninth switch 25, the eighth outgoing terminal T8 is connected to a common node of the tenth switch 26 and the eleventh switch 27, and the ninth outgoing terminal T9 is connected to a common node of the twelfth switch 28 and the thirteenth switch 29.

The sixth outgoing terminal T6 and the seventh outgoing terminal T7 are respectively used for connecting the first flying capacitor C1. The eighth outgoing terminal T8 and the ninth outgoing terminal T9 are respectively used for connecting the second flying capacitor C2.

The switches may be any suitable switching devices such as metal-oxide semiconductor field effect transistors (MOSFETs), Insulated Gate Bipolar Transistors (IGBTs), Integrated Gate Commutated Thyristors (IGCTs), gate turn-off thyristors (GTOs), junction gate field effect transistors (JFETs), MOS Controlled Thyristors (MCTs), gallium nitride (GaN) based power devices, silicon carbide (SiC) based power devices, Silicon Controlled Rectifier (SCR) devices, and the like.

In the embodiments shown in fig. 5a, 5b, 5c and 5d, each switch (e.g., fourth switch 12) is implemented as a single N-type transistor, but those skilled in the art will recognize that many variations, modifications and substitutions are possible. For example, all or at least some of the switches may be implemented as P-type transistors, depending on different applications and design needs. Further, each switch may be implemented as a plurality of switches connected in parallel.

By dividing the components in the battery charging apparatus into modules such as the switching converter 10, the switched capacitor converter 20, and the respective switching units, and providing the lead terminals, various connection modes between the respective modules can be realized. Based on different connection modes, one or more combinations of the external power supply, the switching converter 10 and the switched capacitor conversion device 20 can be realized to charge the battery and supply power to the load, and the universality of the battery charging circuit can be increased.

The battery charging circuit of the embodiment of the invention has at least one first connection mode and at least one second connection mode, in the first connection mode, the battery charging device is configured to supply power for a single battery, and in the second connection mode, the battery charging device is configured to supply power for a double battery.

For example, the embodiments shown in fig. 5a, 5b, 5c and 5d each have at least one first connection mode and at least one second connection mode. The only difference is that in figure 5d the first and second flying capacitors C1, C2 are not integrated and additional connections are required for the first and second flying capacitors C1, C2. In fig. 5a, the second switch unit 30 is not provided, so that other modules cannot be connected to the power supply through the second switch unit. In fig. 5a and 5b, since the third switching unit 50 and the fifth outgoing terminal T5 are not provided, isolation of the switching converter 10 from the lower stage circuit cannot be provided.

In the following, the connection modes are illustrated by way of example in fig. 5d, one first connection mode being:

the third leading terminal T3 is used for connecting a power supply, the fourth leading terminal T4 is connected with the first input leading terminal I1, the first output leading terminal O1 is used for connecting a load, the fifth leading terminal T5 is connected with the second output leading terminal O2 and the single battery, the second input leading terminal I2 is connected with the second leading terminal T2, and the first leading terminal T1 is connected with the third leading terminal T3 or the fourth leading terminal T4.

When the first flying capacitor and the second flying capacitor are not integrated in the switched capacitor converter 20, the sixth outgoing terminal T6 and the seventh outgoing terminal T7 need to be connected to the first flying capacitor C1, respectively. The eighth lead terminal T8 and the ninth lead terminal T9 are connected to the second flying capacitor C2, respectively.

In the case where the battery charging circuit does not include the second switching unit 30, the first input lead terminal I1 and the first lead terminal T1 may be directly connected to the external power source.

Fig. 6 is a schematic diagram of a battery charging apparatus formed after connecting the leading terminals according to the connection mode, please refer to fig. 6, one end of the second switch 31 (source) is configured to be connected with the power source coupled to VIN, the other end (drain) of the second switch 31 is used for connecting the input end of the switching converter, and the output end of the switching converter is connected with the single battery through the third switch 52. One end (drain) of the first switch 42 is connected to the power supply, the other end (source) of the first switch 42 is connected to the input end of the switched capacitor converter, and the output end of the switched capacitor converter is connected to the single battery.

In the embodiment shown in fig. 6, the first outgoing terminal T1 is connected to the third outgoing terminal T3, and in other embodiments, the first outgoing terminal T1 may also be connected to the fourth outgoing terminal T4. In this way, the first leading terminal is connected to VIN through the second switch 31, and the second switch 31 can provide reverse protection, so as to prevent the current from flowing backward to VIN through the first leading terminal T1.

The battery charging device is used for charging a single battery, and when the battery charging device works, the switch converter works in a voltage reduction mode, and the switch capacitor converter works in a 2:1 charge pump mode. The switching converter is used to down-convert the input voltage provided at VIN to obtain the appropriate output voltage for providing to VSYS for powering the load, and to VBAT for charging the single cell battery through the third switch 52.

The switched-capacitor converter is used to down-convert the input voltage provided at VIN to obtain the appropriate output voltage for charging the single battery, and to power the load through the third switch 52. The single battery may also provide power to the load through the third switch 52 when power is not applied at VIN.

The switched-mode converter and the switched-capacitor converter can be used for charging the battery in different phases, for example where the battery charging is divided into a pre-charging phase, a constant-current charging phase and a constant-voltage charging phase. During the pre-charge phase, the single battery is charged by the switching converter, and when the single battery is charged in the constant current mode, the switching capacitor converter is enabled, while the switching converter is disabled, and the switching capacitor converter supplies power to the single battery. When the battery voltage exceeds a certain threshold (e.g., 4.2V), the battery enters a constant voltage charging mode.

In the front stage of the constant voltage charging stage, the battery is supplied by the switched capacitor converter, the charging current decreases with the increase of the battery voltage, and when the charging current drops below a certain threshold (for example, 2A), the switched capacitor converter supplies a constant voltage to the battery to complete the battery charging process.

Wherein the first and second connection modes are: the third outgoing terminal T3 is used for connecting a power supply, the fourth outgoing terminal T4 is connected to the first input outgoing terminal I1, the first output outgoing terminal O1 is connected to the second output outgoing terminal O2 and is used for connecting a load, the second input outgoing terminal I2 is connected to the first outgoing terminal T1, and the second outgoing terminal T2 is used for connecting a double battery.

In the case where the battery charging circuit does not include the second switching unit 30, the first input/output terminal I1 may be directly connected to an external power source.

Fig. 7 is a schematic diagram of a battery charging apparatus formed after connecting the leading terminals according to the second connection mode, please refer to fig. 7, one end of the second switch 31 is configured to be connected to a power source coupled to VIN, the other end of the second switch 31 is used for connecting an input end of the switching converter, and an output end of the switching converter is connected to an output end of the switched capacitor converter through the first output leading terminal O1 and the second output leading terminal O2. The input of the switched capacitor converter is connected to the double cell battery via a first switch 42.

In the embodiment shown in fig. 7, the output terminal of the switching converter is connected to the output terminal of the switched capacitor converter through the first output lead-out terminal O1 and the second output lead-out terminal O2, and the third switching unit 50 is short-circuited, in other words, in the battery charging device, the third switching unit is disabled.

The battery charging device is used for charging double batteries, and when the battery charging device works, the switch converter works in a voltage reduction mode, and the switch capacitor converter works in a 1:2 charge pump mode. The switching converter is used to down-convert the input voltage provided at VIN to obtain the appropriate output voltage for providing to VSYS for powering the load, and to the output (which is the actual input) of the switched-capacitor converter.

The output (i.e., the actual input) of the switched capacitor converter receives power from the output of the switched capacitor converter, which doubles the voltage on VSYS through voltage conversion, and outputs the multiplied voltage at the input (i.e., the actual output) of the switched capacitor converter, which charges the dual battery through the first switch 42. The battery charging apparatus achieves a desired dual battery charging voltage by adjusting an output voltage of the switching converter.

When no external power supply is connected to VIN, the switched capacitor converter operates in a 2:1 charge pump mode to maintain the voltage on VSYS by discharging the dual batteries.

When the battery charging mode is divided into a pre-charging stage, a constant current charging stage and a constant voltage charging stage, the battery is charged in the pre-charging stage, the constant current charging stage and the constant voltage charging stage through the matching work of the switch converter and the switch capacitor converter. During the pre-charge phase, the charging current through the dual battery is controlled by the first switch 42.

The second connection mode is: the third outgoing terminal T3 is used for connecting a power supply, the fourth outgoing terminal T4 is connected to the first output outgoing terminal O1, the first input outgoing terminal I1 is connected to the first outgoing terminal T1 and the second input outgoing terminal I2, the second output outgoing terminal O2 is used for connecting a load, and the second outgoing terminal T2 is used for connecting a double battery.

Fig. 8 is a schematic structural diagram of the battery charging apparatus formed after the leading-out terminals are connected according to the second connection mode, please refer to fig. 8, one end of the second switch 31 is configured to be connected to the power source coupled to VIN, the other end of the second switch 31 is used for connecting the output end (actual input end) of the switching converter, the input end (actual output end) of the switching converter is connected to the input end of the switched capacitor converter, and the input end (actual output end) of the switching converter is further connected to the dual battery through the first switch 42.

The battery charging device is used for charging double batteries, and when the battery charging device works, the switch converter works in a boosting mode, and the switch capacitor converter works in a 2:1 charge pump mode. The switch converter is configured to perform boost conversion on the input voltage provided at VIN to obtain a suitable output voltage, charge the dual battery through the first switch 42, and provide the output voltage to an input end of the switched capacitor converter, where the switched capacitor converter performs buck conversion, and the output voltage supplies power to a load.

When the battery charging mode is divided into a pre-charging stage, a constant current charging stage and a constant voltage charging stage, the battery is charged through the switch converter in the pre-charging stage, the constant current charging stage and the constant voltage charging stage. In the pre-charging stage, the charging current flowing through the two batteries is controlled by the first switch 42 operating in a linear voltage stabilization state, and when the battery voltage reaches the output voltage of the switching converter or reaches the battery voltage threshold value entering the constant current charging mode, the first switch 42 is fully turned on to realize high-efficiency charging.

The embodiment of the present invention further provides a third second connection mode, and the third second connection mode is different from the second connection mode in that in the third connection mode, the fifth outgoing terminal T5 is further used for connecting the load, and as shown in fig. 9, the fifth outgoing terminal is further connected to the voltage bus VSYS.

The battery charging apparatus formed by the third second connection method also provides the function of directly supplying power to the load from the external power source coupled to VIN, in which case the input voltage is usually adjustable, and the voltage required by the load is obtained by adjusting the input voltage.

It should be noted that the first connection mode, the first second connection mode, the second connection mode, and the third second connection mode illustrated above are also applicable to the battery charging circuit shown in fig. 5 c. The first and second connection modes are equally applicable to the battery charging circuit shown in fig. 5a, 5 b.

The battery charging circuit shown in fig. 5a and 5b may further adopt a fourth said second connection mode: the third leading-out terminal T3 is used for connecting a power supply, the fourth leading-out terminal T4 is connected with a first input leading-out terminal I1, the first output leading-out terminal O1 is used for connecting a load and is connected with the first leading-out terminal T1, the second leading-out terminal T2 is connected with a second output leading-out terminal O2, and the second input leading-out terminal I2 is used for connecting the double-section battery.

When the first flying capacitor and the second flying capacitor are not integrated in the switched capacitor converter 20, the sixth outgoing terminal T6 and the seventh outgoing terminal T7 need to be connected to the first flying capacitor C1, respectively. The eighth lead terminal T8 and the ninth lead terminal T9 are connected to the second flying capacitor C2, respectively. In the case where the battery charging circuit does not include the second switching unit 30, the first input/output terminal I1 may be directly connected to an external power source.

In this second connection mode, the first switch may be the isolating switch 43, and the isolating switch is controlled by the first controller 44. Fig. 10 is a schematic structural diagram of the battery charging apparatus formed after the lead terminals are connected according to the second connection mode, please refer to fig. 10, one end of the second switch 31 is configured to be connected to the power source coupled to VIN, the other end of the second switch 31 is used for connecting the input end of the switching converter, and the output end of the switching converter is used for supplying power to the load. The output of the switched capacitor converter is also coupled to the output (which is the actual input) of the switched capacitor converter through the isolation switch 43, and the input (which is the actual output) of the switched capacitor converter is also connected to the double battery.

In this embodiment, the switch-capacitor converter 10 operates in a buck mode, and the switch-capacitor converter operates in a 1:2 charge pump mode. When an input voltage is provided at the external power VIN terminal, the switching converter 10 receives the input voltage, converts the input voltage, and outputs the converted input voltage to the output voltage bus VSYS and the voltage bus BAT. The output (which is the actual input) of the switched-capacitor converter 20 receives the voltage from the voltage bus BAT, converts it, and charges the dual battery via the voltage bus VBAT.

In the actual layout of the modules, considering that the switching converter 10, the second switching unit 30, and the third switching unit 50 have more connection tightness, it is considered that the three modules are arranged in the first layout region (in the case where the third switching unit 50 is not provided, the switching converter 10 and the second switching unit 30 may be arranged in the first layout region, and in the case where neither the second switching unit 30 nor the third switching unit 50 is provided, the switching converter 10 may be arranged in the first layout region). And the switched capacitor converter 20 and the first switching unit 40 are arranged in the second layout region.

In practical applications, the first layout region and the second layout region may be respectively disposed on the first device and the second device, for example, the first layout region and the second layout region are respectively disposed on two printed circuit boards disposed adjacently or stacked. The first layout region and the second layout region may also be arranged at different regions of the same third device, for example, a left region and a right region of the same printed circuit board.

In this case, the outgoing terminals of each module may be arranged along the circumference of the module for convenience of wiring, for example, in the embodiments shown in fig. 5a, 5b and 5c, each outgoing terminal is located in the peripheral region of each module.

In the embodiments shown in fig. 5a, 5b, 5c and 5d, the switching unit charge controller 11 is configured to generate gate drive signals for the second switch 31, the fourth switch 12 and the fifth switch 13. The switching unit capacitance charging controller 21 is configured to generate gate drive signals for a sixth switch 22, a seventh switch 23, an eighth switch 24, a ninth switch 25, a tenth switch 26, an eleventh switch 27, a twelfth switch 28, and a thirteenth switch 29. The mode controller 41 is configured to generate a gate drive signal for the first switch 42. The power path controller 51 is configured to generate a gate drive signal for the third switch 52.

The switch charge controller 11 and the power supply path controller 51 are switched in consideration of convenience in wiring

Alternatively, the switched capacitor charging controller 21 and the mode controller 41 may be disposed in the first layout area.

In other embodiments, more or fewer controllers may be used according to the actual application, for example, only one controller is disposed in the first layout area for collectively controlling the second switch 31, the fourth switch 12, the fifth switch 13, and the third switch 52. Only one controller is provided in the second layout area for collectively controlling the first switch 42, the sixth switch 22, the seventh switch 23, the eighth switch 24, the ninth switch 25, the tenth switch 26, the eleventh switch 27, the twelfth switch 28, and the thirteenth switch 29.

In other embodiments, the modules may be arranged as a whole in the same third layout area, which is located in a third device. In this case, referring to fig. 11, the lead-out terminals of the respective modules may be disposed at the periphery of the entire third layout region.

Please refer to fig. 12, 13, 14, and 15 for the structure of the battery charging apparatus obtained after the modules are laid out in the same area and connected. Fig. 12, fig. 13, fig. 14 and fig. 15 are corresponding to fig. 6, fig. 7, fig. 8 and fig. 9, and are not repeated herein.

In this layout, referring to fig. 11, the switching unit charging controller 11 is configured to generate gate driving signals for the second switch 31, the fourth switch 12, and the fifth switch 13. The switching unit capacitance charging controller 21 is configured to generate gate drive signals for a sixth switch 22, a seventh switch 23, an eighth switch 24, a ninth switch 25, a tenth switch 26, an eleventh switch 27, a twelfth switch 28, and a thirteenth switch 29. The mode controller 41 is configured to generate a gate drive signal for the first switch 42. The power path controller 51 is configured to generate a gate drive signal for the third switch 52.

The switched charge controller 11, the power path controller 51, the switched capacitor charge controller 21 and the mode controller 41 may be laid out in any suitable area of the third layout area.

In other embodiments, more or fewer controllers may be used according to the actual application, for example, only one controller is disposed in the third layout area for collectively controlling the second switch 31, the fourth switch 12, the fifth switch 13, the third switch 52, the first switch 42, the sixth switch 22, the seventh switch 23, the eighth switch 24, the ninth switch 25, the tenth switch 26, the eleventh switch 27, the twelfth switch 28, and the thirteenth switch 29.

Alternatively, only two controllers are provided. One of the controllers is used to collectively control the second switch 31, the fourth switch 12, the fifth switch 13, and the third switch 52. And the other controller is used for uniformly controlling the first switch 42, the sixth switch 22, the seventh switch 23, the eighth switch 24, the ninth switch 25, the tenth switch 26, the eleventh switch 27, the twelfth switch 28 and the thirteenth switch 29.

When the lead terminals are connected to form a battery charging device, appropriate input capacitors, output capacitors, and the like may be connected to the respective modules according to the actual application requirements. For example, the capacitances C3, C4, C5, C6, and C7 shown in fig. 6.

In fig. 6 to 15, the dashed lines are not actual connecting lines but auxiliary lines for easily distinguishing and displaying the blocks, and the devices in the dashed line frame constitute one block.

Through the above description of the embodiments, those skilled in the art will clearly understand that each embodiment can be implemented by software plus a general hardware platform, and certainly can also be implemented by hardware. Based on such understanding, the above technical solutions substantially or contributing to the related art may be embodied in the form of a software product, which may be stored in a computer-readable storage medium, such as ROM/RAM, magnetic disk, optical disk, etc., and includes instructions for causing a computer device (which may be a personal computer, a server, or a network device, etc.) to execute the method according to the embodiments or some parts of the embodiments.

Finally, it should be noted that: the above examples are only intended to illustrate the technical solution of the present invention, but not to limit it; within the idea of the invention, also technical features in the above embodiments or in different embodiments may be combined, steps may be implemented in any order, and there are many other variations of the different aspects of the invention as described above, which are not provided in detail for the sake of brevity; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and the modifications or the substitutions do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A battery charging circuit, comprising:

a switching converter having a first input lead terminal and a first output lead terminal, the switching converter being a voltage converter configured to operate in a boost mode or a buck mode;

a switched capacitor converter having a second input terminal and a second output terminal, the switched capacitor converter being a charge pump converter configured to operate in a fixed-rate boost charge pump mode or a fixed-rate buck charge pump mode;

2. The battery charging circuit of claim 1, further comprising:

a second switching unit having a third lead-out terminal and a fourth lead-out terminal, the second switching unit being configured to turn on or off a connection of the third lead-out terminal and the fourth lead-out terminal.

3. The battery charging circuit of claim 2, wherein the first switching unit comprises a first switch and the second switching unit comprises a second switch;

4. The battery charging circuit of claim 3, further comprising:

5. The battery charging circuit of claim 4, wherein one of said first connection modes is:

6. The battery charging circuit according to any of claims 2-4, wherein the first of said second connection modes is:

7. The battery charging circuit of claim 4, wherein a second one of said second connection modes is:

8. The battery charging circuit of claim 7, wherein the fifth outgoing terminal is further configured to connect to the load.

9. A battery charging circuit as claimed in claim 2 or 3, wherein the fourth said second connection mode is:

10. The battery charging circuit of claim 1, wherein the switching converter is integrated into a first device, and the switched-capacitor converter and the first switching unit are integrated into a second device;

11. The battery charging circuit of claim 10, wherein when the switching converter, the switched-capacitor converter, and the first switching unit are integrated in a third device, the switching converter is located in a first layout area, and the first switching unit and the switched-capacitor converter are located in a second layout area; alternatively, the first and second electrodes may be,

12. The battery charging circuit of claim 3, wherein the switching converter comprises:

13. The battery charging circuit of claim 3, wherein the switched-capacitor converter comprises:

14. A battery charging apparatus, comprising: the battery charging circuit of any of claims 1-13, wherein the connection of the terminals is configured in a first connection mode or a second connection mode, the connection of the terminals being configured in the first connection mode when the battery charging apparatus is used to power a single battery, and the connection of the terminals being configured in the second connection mode when the battery charging apparatus is used to power a double battery.

15. A terminal device, characterized in that the terminal device comprises the battery charging apparatus according to claim 14 and a battery, wherein the battery is a single battery or a double battery.