Battery charging circuit and device having the same

Abstract

The application relates to a battery charging circuit and a device with the same. The charging circuit comprises a first switch, a second switch, a third switch, a fourth switch, a fifth switch, a sixth switch, a seventh switch, a first energy storage unit, a second energy storage unit, a third energy storage unit and an output filter capacitor. The application controls the battery charging circuit by controlling the conduction and non-conduction of the first switch, the second switch, the third switch, the fourth switch, the fifth switch, the sixth switch and the seventh switch. The application realizes a battery charging circuit with a large output voltage span and a wide gain, and can better adapt to the small change of the charging duty cycle of the battery under the full charging and full discharging condition, and improves the charging efficiency.

Description

Technical Field

[0001] This application relates to the field of battery charging technology, and more particularly to a battery charging circuit and an apparatus having the same. Background Technology

[0002] In related technologies, a two-cell battery charging scheme is commonly used to increase the charging power of terminal devices, reducing charging current and device stress while maintaining the same power level. However, for a two-cell battery charging scheme, taking a mobile phone as an example, the battery voltage is around 4V when near discharge, while it is around 9V when fully charged. This results in a large voltage range during the charging and discharging process, leading to reduced charging efficiency in traditional charging circuits under such a large gain range. Figure 1 As shown, Figure 1 This is a type of traditional charging circuit. The circuit shown in the figure is a BUCK circuit, which adjusts the duty cycle of the switching transistor according to changes in battery voltage. When the battery is low in charge, the duty cycle is adjusted to be smaller to meet the charging needs, but the charging efficiency of the battery decreases at this time. Summary of the Invention

[0003] To overcome the problems existing in the related technologies, this application provides a battery charging circuit and an apparatus having the same.

[0004] According to a first aspect of the embodiments of this application, a battery charging circuit is provided, comprising:

[0005] A first switch and a second switch, one end of the first switch is connected to the positive terminal of the circuit input power supply, and one end of the second switch is grounded to the negative terminal of the circuit input power supply;

[0006] The first energy storage unit, one end of which is connected to the other end of the first switch and the other end of the second switch respectively;

[0007] The second energy storage unit, the third switch, and the fourth switch are respectively connected to the other end of the first energy storage unit.

[0008] The fifth switch, one end of which is connected to the other end of the second energy storage unit, and the other end of which is connected to the other end of the third switch;

[0009] The third energy storage unit, the sixth switch, and the seventh switch are respectively connected to the other end of the fourth switch at one end of the third energy storage unit and the sixth switch at one end of the sixth switch. The other end of the third energy storage unit and the seventh switch are respectively connected to the other end of the fifth switch and the other end of the third switch. The other end of the sixth switch is connected to the other end of the seventh switch.

[0010] An output filter capacitor is provided, one end of which is connected to the other end of the second energy storage unit, one end of the fifth switch, and the negative terminal of the battery, and the other end of which is connected to the other end of the sixth switch, the other end of the seventh switch, and the positive terminal of the battery; wherein the positive terminal of the battery is grounded.

[0011] In some embodiments of this application, when the first switch, the fourth switch, the fifth switch, and the seventh switch are turned on, and the second switch, the third switch, and the sixth switch are turned off, the battery charging circuit inputs power to charge the first energy storage unit, the second energy storage unit, and the third energy storage unit, and the output filter capacitor provides energy to the battery.

[0012] When the first switch, the fourth switch, the fifth switch, and the seventh switch are off, and the second switch, the third switch, and the sixth switch are turned on, the first energy storage unit provides freewheeling energy, and the second energy storage unit and the third energy storage unit are connected in series to provide energy for the output filter capacitor and the battery.

[0013] In some embodiments of this application, the first switch, the second switch, the third switch, and the sixth switch are all NMOS transistors.

[0014] In some embodiments of this application, the fourth switch, the fifth switch, and the seventh switch are diodes.

[0015] In some embodiments of this application, one end of the fourth switch, one end of the fifth switch, and one end of the seventh switch are respectively the anode of the diode; the other end of the fourth switch, the other end of the fifth switch, and the other end of the seventh switch are respectively the cathode of the diode.

[0016] In some embodiments of this application, the first energy storage unit is an energy storage inductor.

[0017] In some embodiments of this application, both the second energy storage unit and the third energy storage unit are non-inductive capacitors.

[0018] According to a second aspect of the embodiments of this application, a battery charging device is provided, comprising:

[0019] The battery charging circuit as described in the first aspect above;

[0020] A current conversion module is used to convert AC power from the power grid into DC power.

[0021] A TYPE-C interface; wherein, the DC power supplies the TYPE-C interface, and the DC power received by the TYPE-C interface is regulated by the battery charging circuit to charge the battery.

[0022] In some embodiments of this application, the battery charging device further includes:

[0023] A driving circuit is configured to drive the first switch to turn on and the second switch, the third switch, and the sixth switch to turn off in the first phase of the switching cycle, and to drive the first switch to turn off and the second switch, the third switch, and the sixth switch to turn on in the second phase of the switching cycle.

[0024] According to a third aspect of the embodiments of this application, a terminal device is provided, including the battery charging circuit described in the first aspect above.

[0025] According to a fourth aspect of the embodiments of this application, a terminal device is provided, including the battery charging device described in the second aspect above.

[0026] The technical solutions provided by the embodiments of this application may include the following beneficial effects:

[0027] The battery charging circuit proposed in this application uses active devices to reduce losses and achieve higher circuit conversion efficiency. By controlling the on / off states of the first, second, third, and sixth switches, the battery charging circuit is divided into two stages. In the first stage, the battery charging circuit is powered by the input power source, and in the second stage, it is powered by the first, second, and third energy storage units. This achieves a battery charging circuit with a wide output voltage range and broad gain, making it more adaptable to situations where the battery's duty cycle does not change significantly during full charge and discharge, thus improving charging efficiency.

[0028] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and do not limit this application. Attached Figure Description

[0029] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0030] Figure 1 This is a schematic diagram of a charging circuit in the prior art;

[0031] Figure 2 This is a schematic diagram of a battery charging circuit according to an exemplary embodiment;

[0032] Figure 3 The current I of the first energy storage unit L shown according to an exemplary embodiment LA waveform diagram;

[0033] Figure 4 This is a schematic diagram of the current flow in the first half of a battery charging circuit according to an exemplary embodiment.

[0034] Figure 5 This is a schematic diagram of the current flow in the second half of the battery charging cycle according to an exemplary embodiment.

[0035] Figure 6 This is a schematic diagram of the structure of a battery charging device according to an exemplary embodiment;

[0036] Figure 7 This is a schematic diagram of the structure of another battery charging device according to an exemplary embodiment; Detailed Implementation

[0037] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numbers in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this application. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this application as detailed in the appended claims.

[0038] It's important to note that the charging power of current terminal devices (such as smartphones) is constantly increasing. With this increase, the current carrying capacity of the charging circuit also increases significantly, leading to a quadratic increase in line losses during charging and a decrease in charging efficiency. Limited by the current-carrying capacity of the charging circuit, further increases in charging power have reached a bottleneck. To address this, the industry has proposed a two-cell battery charging scheme to reduce the charging current and decrease device stress at the same power level. One approach is to increase the charging current; however, this approach results in a significant increase in line losses as the charging current increases, and the current-carrying capacity of the charging circuit is limited and cannot be increased indefinitely. Another approach is to increase the charging voltage. In this scheme, two cells are used. When the cells are nearly discharged, the voltage is around 4V, while a fully charged phone battery has a voltage of 9V. Therefore, the voltage difference during a full charge and discharge cycle is particularly large. This places high demands on the gain range of the battery charging circuit; traditional circuits become very inefficient under such large gain ranges.

[0039] Therefore, this application proposes a wide-gain, high-efficiency battery charging circuit. The battery consists of two cells connected in series. The battery charging circuit includes: a first switch, a second switch, a third switch, a fourth switch, a fifth switch, a sixth switch, a seventh switch, a first energy storage unit, a second energy storage unit, a third energy storage unit, and an output filter capacitor. The first, second, third, fourth, fifth, sixth, and seventh switches can be, but are not limited to, any one of a MOS (Metal Oxide Semiconductor) transistor, a diode, or an IGBT (Insulated Gate Bipolar Transistor). As an example, the first, second, third, and sixth switches can be MOS transistors, such as N-MOS (N-type Metal Oxide Semiconductor) transistors or P-MOS (P-type Metal Oxide Semiconductor) transistors; the fifth and seventh switches can be diodes.

[0040] In the embodiments of this disclosure, the first energy storage unit, the second energy storage unit, and the third energy storage unit can be devices with energy storage and discharge functions. As an example, the first energy storage unit can be an energy storage inductor; the second energy storage unit and the third energy storage unit can each be a non-inductive capacitor.

[0041] To facilitate those skilled in the art in understanding the connection relationships of the various components in the battery charging circuit proposed in this application, the following description will use the first, second, third, and sixth switches as MOSFETs, the fifth and seventh switches as diodes, the first energy storage unit as an energy storage inductor, and the second and third energy storage units as non-inductive capacitors as examples to illustrate the battery charging circuit proposed in this application.

[0042] Figure 2 This is a schematic diagram of a battery charging circuit according to an exemplary embodiment. The battery charging circuit includes: a first switch Q1, a second switch Q2, a third switch Q3, a fourth switch D1, a fifth switch D2, a sixth switch Q4, a seventh switch D3, a first energy storage unit L, a second energy storage unit C1, a third energy storage unit C2, and an output filter capacitor C0.

[0043] In this circuit, one end of the first switch Q1 is connected to the positive terminal of the circuit input power supply, and one end of the second switch Q2 is grounded to the negative terminal of the circuit input power supply; one end of the first energy storage unit L is connected to the other end of the first switch Q1 and the other end of the second switch Q2; one end of the second energy storage unit C1, one end of the third switch Q3, and one end of the fourth switch D1 are connected to the other end of the first energy storage unit L; one end of the fifth switch D2 is connected to the other end of the second energy storage unit C1, and the other end of the fifth switch D2 is connected to the other end of the third switch Q3; one end of the third energy storage unit C2 and one end of the sixth switch Q4 are connected to the other end of the circuit input power supply. One end of the first switch is connected to the other end of the fourth switch D1. The other end of the third energy storage unit C2 and one end of the seventh switch D3 are connected to the other ends of the fifth switch D2 and the third switch Q3, respectively. The other end of the sixth switch Q4 is connected to the other end of the seventh switch D3. One end of the output filter capacitor C0 is connected to the other end of the second energy storage unit C1, one end of the fifth switch D2 and the negative terminal of the battery cell, respectively. The other end of the output filter capacitor C0 is connected to the other end of the sixth switch Q4, the other end of the seventh switch D3 and the positive terminal of the battery cell, respectively. The positive terminal of the battery cell is grounded.

[0044] In some embodiments of this application, the first switch Q1, the second switch Q2, the third switch Q3 and the sixth switch Q4 are NMOS transistors.

[0045] For example, such as Figure 2 As shown, the drain of the first switch Q1 is connected to the circuit input power supply V. IN The positive terminal of the first switch Q1 is connected to the first switch Q2, and one end of the second switch Q2 is grounded to the negative terminal of the circuit input power supply. One end of the first energy storage unit L is connected to the source of the first switch Q1 and the drain of the second switch Q2. One end of the second energy storage unit C1, the drain of the third switch Q3, and the anode of the fourth switch D1 are connected to the other end of the first energy storage unit L. The cathode of the fifth switch D2 is connected to the other end of the second energy storage unit C1, and the anode of the fifth switch D2 is connected to the source of the third switch Q3. One end of the third energy storage unit C2 and the drain of the sixth switch Q4 are connected to the source of the fourth switch Q3. The cathode of switch D1 is connected, the other end of the third energy storage unit C2 and the anode of the seventh switch D3 are connected to the cathode of the fifth switch D2 and the source of the third switch Q3, respectively, and the source of the sixth switch Q4 is connected to the cathode of the seventh switch D3; the output filter capacitor C0 has one end connected to the other end of the second energy storage unit C1, the anode of the fifth switch D2 and the negative terminal of the battery cell, respectively, and the other end connected to the source of the sixth switch Q4, the cathode of the seventh switch D3 and the positive terminal of the battery cell, respectively.

[0046] It should also be noted that the battery charging circuit in this application embodiment can control the on and off of the first switch Q1, the second switch Q2, the third switch Q3 and the sixth switch Q4 through the driving circuit. The driving signals of the second switch Q2, the third switch Q3 and the sixth switch Q4 are the same, and they are turned on and off simultaneously. The driving signal of the first switch Q1 is complementary to the driving signals of the second switch Q2, the third switch Q3 and the sixth switch Q4. Figure 3 The current I of the first energy storage unit L under the control of the drive circuit L The waveform diagram is shown below. When the first switch Q1 is turned on, the first energy storage unit L is charged and stores energy; when the first switch Q1 is turned off, the first energy storage unit L acts as a power source to provide freewheeling current for the circuit. Figure 3 In the middle T, one switching cycle is represented.

[0047] In some embodiments of this application, when the first switch Q1, the fourth switch D1, the fifth switch D2, and the seventh switch D3 are turned on, and the second switch Q2, the third switch Q3, and the sixth switch Q4 are turned off, the circuit input power supply V... IN The first energy storage unit L, the second energy storage unit C1 and the third energy storage unit C2 are charged, and the output filter capacitor C0 provides energy to the battery cell.

[0048] When the first switch Q1, the fourth switch D1, the fifth switch D2, and the seventh switch D3 are off, and the second switch Q2, the third switch Q3, and the sixth switch Q4 are on, the first energy storage unit L provides freewheeling energy, and the second energy storage unit C1 and the third energy storage unit C2 are connected in series to provide energy for the output filter capacitor C0 and the battery Cell.

[0049] As an example, Figure 4 and Figure 5 This illustrates the current flow direction in the battery charging circuit proposed in this application under different switching states. For example... Figure 4 As shown, Figure 4 This describes the current flow in the battery charging circuit proposed in this application during the first stage. At this time, the first switch Q1 is on, and the second switch Q2, the third switch Q3, and the sixth switch Q4 are off, with the input power V... IN The first energy storage unit L stores energy to provide energy for the entire circuit, charges the second energy storage unit C1 and the third energy storage unit C2, and then outputs energy to the output filter capacitor C0 and the battery Cell.

[0050] Figure 5 This describes the current flow in the second stage of the battery charging circuit proposed in this embodiment. At this time, the second switch Q2, the third switch Q3, and the sixth switch Q4 are turned on, the first switch Q1 is turned off, and the input power V... INWhen the circuit is cut off, freewheeling energy is provided by the first energy storage unit L. The second energy storage unit C1 and the third energy storage unit C2 are connected in series to provide energy for the output filter capacitor C0 and the battery cell. The circuit output voltage is the sum of the voltages of the second energy storage unit C1 and the third energy storage unit C2. Assuming that the duty cycle of the first switch Q1 is D, the gain of the circuit after steady state in the second stage is:

[0051] Vout = 2 * D * Vin

[0052] Where Vin is the input power supply voltage and Vout is the battery output voltage.

[0053] The battery charging circuit according to the embodiments of this application uses active devices, resulting in higher circuit conversion efficiency and reduced losses. By controlling the on / off states of the first, second, third, and sixth switches through the drive circuit, the switching timing is easily controlled. In the first stage, the battery charging circuit is powered by the input power supply V. IN The first stage provides electrical energy, while the second stage is powered by the first, second, and third energy storage units. This design achieves a battery charging circuit with a wide output voltage range and broad gain, making it more adaptable to situations where the battery's duty cycle does not change significantly during full charge and discharge, thus improving charging efficiency.

[0054] Figure 6 This is a structural block diagram of a battery charging device according to an exemplary embodiment. (Refer to...) Figure 6 The battery charging device includes a battery charging circuit 601, a current conversion module 602, and a TYPE-C interface 603.

[0055] The battery charging circuit 601 is the battery charging circuit in the aforementioned embodiment. The structural diagram and functional description of the battery charging circuit 601 can be found in [reference needed]. Figures 2 to 5 The structural diagram and functional description of the battery charging circuit described in any of the embodiments are not repeated here;

[0056] The current conversion module 602 is used to convert AC power from the power grid into DC power; the current conversion module 602 can be placed in the wired charger of the terminal device.

[0057] The TYPE-C interface 603 is powered by DC power. The DC power received by the TYPE-C interface is regulated by the battery charging circuit 601 to charge the battery.

[0058] Optionally, such as Figure 7 As shown, in some embodiments of this application, the battery charging device may further include a drive circuit 704.

[0059] The driving circuit 704 is used to drive the first switch to turn on and the second, third, and sixth switches to turn off during the first phase of the switching cycle, and to drive the first switch to turn off and the second, third, and sixth switches to turn on during the second phase of the switching cycle. Figure 7 701-703 and Figure 6 The 601-603 series have the same function and structure.

[0060] To implement the above embodiments, this application also proposes a terminal device, including the battery charging circuit in the above embodiments. The structural diagram and functional description of the battery charging circuit can be found in [reference needed]. Figures 2 to 5 The structural diagram and functional description of the battery charging circuit described in any of the embodiments are not repeated here.

[0061] To implement the above embodiments, this application also proposes a terminal device, including the battery charging device in the above embodiments, which can be referred to as... Figure 6 and Figure 7 The battery charging device described in any of the embodiments will not be described in detail here.

[0062] Regarding the apparatus in the above embodiments, the specific manner in which each module performs its operation has been described in detail in the embodiments related to the method, and will not be elaborated upon here.

[0063] Other embodiments of this application will readily occur to those skilled in the art upon consideration of the specification and practice of the invention disclosed herein. This application is intended to cover any variations, uses, or adaptations of this application that follow the general principles of this application and include common knowledge or customary techniques in the art not disclosed herein. The specification and examples are to be considered exemplary only, and the true scope and spirit of this application are indicated by the following claims.

[0064] It should be understood that this application is not limited to the precise structure described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of this application is limited only by the appended claims.

Claims

1. A battery charging circuit, characterized in that, include: A first switch and a second switch, one end of the first switch is connected to the positive terminal of the circuit input power supply, and one end of the second switch is grounded to the negative terminal of the circuit input power supply; The first energy storage unit, one end of which is connected to the other end of the first switch and the other end of the second switch respectively; The second energy storage unit, the third switch, and the fourth switch are respectively connected to the other end of the first energy storage unit. The fifth switch, one end of which is connected to the other end of the second energy storage unit, and the other end of which is connected to the other end of the third switch; The third energy storage unit, the sixth switch, and the seventh switch are respectively connected to the other end of the fourth switch at one end of the third energy storage unit and the sixth switch at one end of the sixth switch. The other end of the third energy storage unit and the seventh switch are respectively connected to the other end of the fifth switch and the other end of the third switch. The other end of the sixth switch is connected to the other end of the seventh switch. An output filter capacitor is provided, one end of which is connected to the other end of the second energy storage unit, one end of the fifth switch, and the negative terminal of the battery, and the other end of which is connected to the other end of the sixth switch, the other end of the seventh switch, and the positive terminal of the battery; wherein the positive terminal of the battery is grounded.

2. The battery charging circuit according to claim 1, characterized in that, When the first switch, the fourth switch, the fifth switch, and the seventh switch are turned on, and the second switch, the third switch, and the sixth switch are turned off, the circuit input power supplies charge the first energy storage unit, the second energy storage unit, and the third energy storage unit, and the output filter capacitor provides energy to the battery. When the first switch, the fourth switch, the fifth switch, and the seventh switch are off, and the second switch, the third switch, and the sixth switch are turned on, the first energy storage unit provides freewheeling energy, and the second energy storage unit and the third energy storage unit are connected in series to provide energy for the output filter capacitor and the battery.

3. The battery charging circuit according to claim 1, characterized in that, The first switch, the second switch, the third switch, and the sixth switch are all NMOS transistors.

4. The battery charging circuit according to claim 1, characterized in that, The fourth switch, the fifth switch, and the seventh switch are all diodes.

5. The battery charging circuit according to claim 4, characterized in that, One end of the fourth switch, one end of the fifth switch, and one end of the seventh switch are respectively the anodes of the diode; The other ends of the fourth switch, the fifth switch, and the seventh switch are respectively the cathodes of the diode.

6. The battery charging circuit according to claim 1, characterized in that, The first energy storage unit is an energy storage inductor.

7. The battery charging circuit according to claim 1, characterized in that, Both the second energy storage unit and the third energy storage unit are non-inductive capacitors.

8. A battery charging device, characterized in that, include: The battery charging circuit as described in any one of claims 1 to 7; A current conversion module is used to convert AC power from the power grid into DC power. A TYPE-C interface; wherein, the DC power supplies the TYPE-C interface, and the DC power received by the TYPE-C interface is regulated by the battery charging circuit to charge the battery.

9. The battery charging device according to claim 8, characterized in that, Also includes: A driving circuit is configured to drive the first switch to turn on and the second switch, the third switch, and the sixth switch to turn off in the first phase of the switching cycle, and to drive the first switch to turn off and the second switch, the third switch, and the sixth switch to turn on in the second phase of the switching cycle.

10. A terminal device, characterized in that, include: The battery charging circuit as described in any one of claims 1 to 7.

11. A terminal device, characterized in that, include: The battery charging device as described in claim 8 or 9.

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