A battery charge and discharge management system suitable for single and dual cells

Abstract

The present invention relates to a battery charge and discharge management system suitable for single and double cells, belonging to the technical field of battery charge and discharge. The battery charge and discharge management system comprises: a step-down voltage converter, a switch capacitor voltage converter and a switch tube converter; the step-down voltage converter comprises NMOS tubes M1 to M4 and an inductor L; the switch capacitor voltage converter comprises NMOS tubes M7 to M14; the switch tube converter comprises NMOS tubes M5 and M6. The battery charge and discharge management system suitable for single and double cells provided by the present invention can realize fast charging of single-cell batteries and double-cell battery systems by only using a step-down voltage converter together with a switch capacitor voltage converter and a switch tube converter, and has a simple circuit structure and lower cost.

Description

Technical Field

[0001] The present invention relates to the technical field of battery charging and discharging, and in particular to a battery charging and discharging management system suitable for single and double cells. Background Art

[0002] In lithium battery charging applications, such as the battery charging management system of mobile phones, in order to achieve high-current fast charging of the battery, a switched capacitor voltage converter is used to achieve high-efficiency, high-current charging of the battery. However, when the battery voltage is relatively low, the required charging current is relatively small, and the switched capacitor voltage converter cannot be used to charge when the battery voltage is low. Therefore, a step-down voltage converter is required, and then a switched capacitor voltage converter is connected in parallel to achieve safe and fast charging within the full battery voltage range. In existing mobile phone battery systems, there are single-cell batteries and dual-cell battery systems. In systems with different numbers of cells, the existing solutions require the use of different step-down voltage converters to achieve, which has the problems of complex circuit structure and high cost. Summary of the invention

[0003] The purpose of the present invention is to provide a battery charge and discharge management system suitable for single-cell and double-cell batteries, which can realize fast charging of single-cell batteries and double-cell battery systems by only using a step-down voltage converter together with a switch capacitor voltage converter and a switch tube converter, with a simple circuit structure and lower cost.

[0004] To achieve the above object, the present invention provides the following solutions:

[0005] A battery charge and discharge management system suitable for single and double cells, comprising: a step-down voltage converter, a switched capacitor voltage converter and a switch tube converter; the step-down voltage converter comprises NMOS tubes M1 to M4 and an inductor L; the switched capacitor voltage converter comprises NMOS tubes M7 to M14; the switch tube converter comprises NMOS tubes M5 and M6;

[0006] The gates of the NMOS tubes M1 to M14 are all connected to the control loop output; the source of the NMOS tube M1 is connected to the input voltage VBUS, and the drain voltage of the NMOS tube M1 is VPMID; VPMID is also connected to the drains of the NMOS tubes M2 and M5; the source of the NMOS tube M2 is simultaneously connected to the drain of the NMOS tube M3 and one end of the inductor L; the source of the NMOS tube M3 is grounded; the other end of the inductor L is connected to the drain of the NMOS tube M4; the drain voltage of the NMOS tube M4 is VSYS; the source of the NMOS tube M4 is connected to the single-cell connection point V1X;

[0007] The source of the NMOS tube M7 is connected to the drain of the NMOS tube M8, the source of the NMOS tube M8 is connected to the drain of the NMOS tube M9, the source of the NMOS tube M9 is connected to the drain of the NMOS tube M10, and the source of the NMOS tube M10 is grounded; the source of the NMOS tube M14 is connected to the drain of the NMOS tube M13, the source of the NMOS tube M13 is connected to the drain of the NMOS tube M12, and the source of the NMOS tube M12 is grounded. The source is connected to the drain of the NMOS tube M11, and the source of the NMOS tube M11 is grounded; the sources of the NMOS tube M8 and the NMOS tube M13 are both connected to the source of the NMOS tube M4; the drain of the NMOS tube M7 and the drain of the NMOS tube M14 are both connected to the drain of the NMOS tube M6; the drain of the NMOS tube M6 is connected to the double-cell connection V2X; the source of the NMOS tube M6 is connected to the source of the NMOS tube M5.

[0008] Optionally, the switched capacitor voltage converter is a switched capacitor voltage converter with a forward 1:2 boost and a reverse 2:1 buck.

[0009] Optionally, in the step-down voltage converter, the NMOS tube M1 is used as an isolation switch; the NMOS tubes M2 and M3 are used as power switches; and the NMOS tube M4 is used as a power management switch.

[0010] Optionally, in the switched capacitor voltage converter, the NMOS transistors M7 to M14 are used as power switches.

[0011] Optionally, in the switch tube converter, the NMOS tubes M5 and M6 are used as high-voltage direct charging switches.

[0012] Optionally, the single-cell connection V1X is connected to a single-cell battery; and the double-cell connection V2X is connected to a double-cell battery.

[0013] According to the specific embodiments provided by the present invention, the present invention discloses the following technical effects:

[0014] The present invention provides a battery charge and discharge management system suitable for single and double cells, comprising: a step-down voltage converter, a switch capacitor voltage converter and a switch tube converter; the step-down voltage converter comprises NMOS tubes M1-M4 and an inductor L; the switch capacitor voltage converter comprises NMOS tubes M7-M14; the switch tube converter comprises NMOS tubes M5 and M6; the gates of the NMOS tubes M1-M14 are all connected to the control loop output; the source of the NMOS tube M1 is connected to the input voltage VBUS, and the drain voltage of the NMOS tube M1 is VPMID; VPMID is also connected to the drains of the NMOS tubes M2 and M5 at the same time; the gate of the NMOS tube M2 is connected to the input voltage VBUS, and the drain voltage of the NMOS tube M1 is VPMID; VPMID is also connected to the drains of the NMOS tubes M2 and M5 at the same time; the gate of the NMOS tube M2 is connected to the input voltage VBUS, and the drain voltage of the NMOS tube M1 is VPMID; the ... connected to the drains of the NMOS tubes M2 and M5 at the same time; the gate of the NMOS tube M2 is connected to the input voltage VBUS, and the drain voltage of the The source is connected to the drain of the NMOS tube M3 and one end of the inductor L at the same time; the source of the NMOS tube M3 is grounded; the other end of the inductor L is connected to the drain of the NMOS tube M4; the drain voltage of the NMOS tube M4 is VSYS; the source of the NMOS tube M4 is connected to the single-cell connection V1X; the sources of the NMOS tube M8 and the NMOS tube M13 are both connected to the source of the NMOS tube M4; the drain of the NMOS tube M7 and the drain of the NMOS tube M14 are both connected to the drain of the NMOS tube M6; the drain of the NMOS tube M6 is connected to the double-cell connection V2X; the source of the NMOS tube M6 is connected to the source of the NMOS tube M5. The battery charge and discharge management system suitable for single and double cells provided by the present invention can realize the fast charging of single-cell batteries and double-cell battery systems by only using a step-down voltage converter together with a switch capacitor voltage converter and a switch tube converter, and the circuit structure is simple and the cost is lower. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0016] Figure 1 A schematic diagram of the circuit structure of a battery charge and discharge management system applicable to single and double cells provided by the present invention;

[0017] Figure 2 A schematic diagram of the charging path of a single-cell battery in the trickle current and constant voltage stages;

[0018] Figure 3 It is a schematic diagram of the charging path of a single-cell battery in the constant current stage;

[0019] Figure 4It is a schematic diagram of the discharge path of a single-cell battery during the discharge stage;

[0020] Figure 5 It is a schematic diagram of the charging path of a dual-cell battery in the trickle current and constant voltage stages;

[0021] Figure 6 It is a schematic diagram of the charging path of a dual-cell battery in the constant current stage;

[0022] Figure 7 Schematic diagram of the discharge path of a dual-cell battery during the discharge stage. DETAILED DESCRIPTION

[0023] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0024] The purpose of the present invention is to provide a battery charge and discharge management system suitable for single-cell and double-cell batteries, which can realize fast charging of single-cell batteries and double-cell battery systems by only using a step-down voltage converter together with a switch capacitor voltage converter and a switch tube converter, with a simple circuit structure and lower cost.

[0025] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0026] Figure 1 This is a schematic diagram of the circuit structure of a battery charge and discharge management system suitable for single and double cells provided by the present invention. Figure 1 The battery charge and discharge management system of the present invention includes: a step-down voltage converter (also called a step-down voltage converter), a switched capacitor voltage converter and a switch tube converter. The step-down voltage converter includes NMOS tubes M1 to M4 and an inductor L. The switched capacitor voltage converter includes NMOS tubes M7 to M14. The switch tube converter includes NMOS tubes M5 and M6.

[0027] Among them, the gates of the NMOS tubes M1 to M14 are all connected to the control loop output, that is, the gates of M1 to M14 are all controlled by the control loop output. The source of the NMOS tube M1 is connected to the input voltage VBUS, and the drain voltage of the NMOS tube M1 is VPMID; VPMID is also connected to the drains of the NMOS tubes M2 and M5 at the same time. The source of the NMOS tube M2 is simultaneously connected to the drain of the NMOS tube M3 and one end of the inductor L; the source of the NMOS tube M3 is grounded; the other end of the inductor L is connected to the drain of the NMOS tube M4; the drain voltage of the NMOS tube M4 is VSYS. The source of the NMOS tube M4 is connected to the single-cell connection V1X.

[0028] The source of the NMOS tube M7 is connected to the drain of the NMOS tube M8, the source of the NMOS tube M8 is connected to the drain of the NMOS tube M9, the source of the NMOS tube M9 is connected to the drain of the NMOS tube M10, and the source of the NMOS tube M10 is grounded; the source of the NMOS tube M14 is connected to the drain of the NMOS tube M13, the source of the NMOS tube M13 is connected to the drain of the NMOS tube M12, and the source of the NMOS tube M12 is grounded. The source is connected to the drain of the NMOS tube M11, and the source of the NMOS tube M11 is grounded; the sources of the NMOS tube M8 and the NMOS tube M13 are both connected to the source of the NMOS tube M4; the drain of the NMOS tube M7 and the drain of the NMOS tube M14 are both connected to the drain of the NMOS tube M6; the drain of the NMOS tube M6 is connected to the double-cell connection V2X; the source of the NMOS tube M6 is connected to the source of the NMOS tube M5.

[0029] The switched capacitor voltage converter is a switched capacitor voltage converter with a forward 1:2 boost and a reverse 2:1 buck.

[0030] In the step-down voltage converter, the NMOS tube M1 is used as an isolation switch; the NMOS tubes M2 and M3 are used as power switches; and the NMOS tube M4 is used as a power management switch.

[0031] In the switched capacitor voltage converter, the NMOS transistors M7 to M14 are used as power switches.

[0032] In the switch tube converter, the NMOS tubes M5 and M6 are used as high-voltage direct charging switches.

[0033] The single-cell connection V1X is connected to a single-cell battery; the double-cell connection V2X is connected to a double-cell battery.

[0034] It can be seen that the battery charge and discharge management system of the present invention supports both single-cell batteries and dual-cell batteries, mainly including: a step-down voltage converter with battery charge and discharge management composed of an isolation switch NMOS tube M1, power switch NMOS tubes M2 and M3, an inductor L and a power management switch NMOS tube M4; a forward 1:2 boost and reverse 2:1 step-down switch capacitor voltage converter composed of power switch NMOS tubes M7 to M14; and a switch tube converter composed of high-voltage direct charging switch NMOS tubes M5 and M6. The battery charge and discharge management system of the present invention has a simple circuit structure and an ingenious implementation method. It only uses a step-down voltage converter and a switch capacitor voltage converter and connects two switch tubes to realize the charge and discharge of single and dual-cell batteries.

[0035] The working process of the battery charge and discharge management system of the present invention is introduced in detail below.

[0036] Figure 2 The figure is a schematic diagram of the charging path of a single-cell battery in the trickle current and constant voltage stages. Figure 2 The input voltage VBUS passes through the NMOS tube M1, making the VBUS voltage equal to the VPMID voltage. The VPMID voltage is converted into the VSYS voltage through the step-down voltage converter, and then the single-cell battery V1X voltage is charged with a small current in the trickle and constant voltage stages through the battery charge and discharge management switch M4. The current path is shown as the thick black solid arrow in the figure.

[0037] Figure 3 The figure is a schematic diagram of the charging path of a single-cell battery in the constant current stage. Figure 3 , the input voltage VBUS passes through the NMOS tube M1, making the VBUS voltage equal to the VPMID voltage, and then passes through the isolation switch tubes M5 and M6, making the VPMID voltage equal to the V2X voltage. The V2X voltage works in reverse through the switch capacitor voltage converter composed of M7~M14, converting V2X into V1X, making V1X=V2X / 2, and charging the battery with a large current. The current path is shown as the black thick solid arrow in the figure.

[0038] Figure 4 The figure is a schematic diagram of the discharge path of a single-cell battery during the discharge phase. Figure 4 , the battery voltage V1X discharges the system power supply voltage VSYS through the battery charge and discharge management switch M4. The current path is shown by the thick black solid arrow in the figure.

[0039] That is, in a single-cell battery system, the single-cell battery is connected to the V1X node. Figure 2 As shown in the figure, when the battery is charged in the trickle current and constant voltage stages, the battery is charged through a step-down voltage converter. When the battery voltage meets the high current charging conditions, it enters the constant current stage of charging, such as Figure 3 As shown, through the high-voltage direct charging switches M5 and M6, the V2X node voltage is equal to the VPMID input voltage, and the switched capacitor voltage converter converts the V2X voltage into 1 / 2*V2X to charge the single-cell battery. Figure 4 As shown, when the battery is discharged, a single-cell battery discharges VSYS through the NMOS tube M4.

[0040] Figure 5 The figure is a schematic diagram of the charging path of a dual-cell battery in the trickle current and constant voltage stages. Figure 5 , the input voltage VBUS passes through the NMOS tube M1, making the VBUS voltage equal to the VPMID voltage, and the VPMID voltage is converted into the VSYS voltage through the step-down voltage converter, and then through the battery charge and discharge management switch M4, making the VSYS voltage equal to the V1X voltage. The V1X voltage is used as the positive input voltage of the switched capacitor voltage converter and converted into the V2X voltage, making V2X = 2*V1X, realizing the trickle and constant voltage stage of the dual-cell battery V2X voltage. The current path is shown as the thick black solid arrow in the figure.

[0041] Figure 6 Figure 1 is a schematic diagram of the charging path of a dual-cell battery in the constant current stage. Figure 6 In the charging path of the dual-cell battery high-voltage direct charging shown in the figure, the input voltage VBUS passes through the NMOS tube M1, making the VBUS voltage equal to the VPMID voltage, and then passes through the isolation switch tubes M5 and M6, making the VPMID voltage equal to the V2X voltage, charging the battery with a large current. The current path is shown by the thick black solid arrow in the figure.

[0042] Figure 7 The figure is a schematic diagram of the discharge path of a dual-cell battery during the discharge phase. Figure 7 , the battery voltage V2X works in reverse through the switched capacitor voltage converter composed of M7 to M14, converting V2X into V1X, so that V1X = V2X / 2, and then V1X discharges the system power supply voltage VSYS through the battery charge and discharge management switch M4. The current path is shown as the black thick solid arrow in the figure.

[0043] That is, in a dual-cell battery system, the dual-cell battery is connected to the V2X node. Figure 5 As shown, when the battery is charged in the trickle and constant voltage stages, the output voltage VPMID is first converted into the V1X node voltage through the step-down voltage converter, and then the V1X voltage is converted into 2*V1X voltage through the switched capacitor voltage converter to charge the dual-cell battery. Figure 6 As shown, when the battery voltage meets the high current charging condition, it enters the constant current stage of charging, and the battery is directly charged through the high voltage direct charging switches M5 and M6. Figure 7 As shown, when the dual-cell battery is discharged, the switched capacitor voltage converter first works in reverse to convert the V2X voltage into V1X=V2X / 2, and then discharges VSYS through the NMOS tube M4.

[0044] It can be seen that the present invention realizes the charge and discharge management of single-cell and double-cell batteries through a simple circuit structure and method.

[0045] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0046] This article uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only used to help understand the control method and its core idea of ​​the present invention. At the same time, for those skilled in the art, according to the idea of ​​the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. A battery charge and discharge management system suitable for single and double cells, characterized in that: include: A step-down voltage converter, a switched capacitor voltage converter and a switch tube converter; the step-down voltage converter includes NMOS tubes M1 to M4 and an inductor L; the switched capacitor voltage converter includes NMOS tubes M7 to M14; the switch tube converter includes NMOS tubes M5 and M6; The gates of the NMOS tubes M1 to M14 are all connected to the control loop output; the source of the NMOS tube M1 is connected to the input voltage VBUS, and the drain voltage of the NMOS tube M1 is VPMID; VPMID is also connected to the drains of the NMOS tubes M2 and M5; the source of the NMOS tube M2 is simultaneously connected to the drain of the NMOS tube M3 and one end of the inductor L; the source of the NMOS tube M3 is grounded; the other end of the inductor L is connected to the drain of the NMOS tube M4; the drain voltage of the NMOS tube M4 is VSYS; the source of the NMOS tube M4 is connected to the single-cell connection point V1X; The source of the NMOS tube M7 is connected to the drain of the NMOS tube M8, the source of the NMOS tube M8 is connected to the drain of the NMOS tube M9, the source of the NMOS tube M9 is connected to the drain of the NMOS tube M10, and the source of the NMOS tube M10 is grounded; the source of the NMOS tube M14 is connected to the drain of the NMOS tube M13, the source of the NMOS tube M13 is connected to the drain of the NMOS tube M12, and the source of the NMOS tube M12 is grounded. The source is connected to the drain of the NMOS tube M11, and the source of the NMOS tube M11 is grounded; the sources of the NMOS tube M8 and the NMOS tube M13 are both connected to the source of the NMOS tube M4; the drain of the NMOS tube M7 and the drain of the NMOS tube M14 are both connected to the drain of the NMOS tube M6; the drain of the NMOS tube M6 is connected to the double-cell connection V2X; the source of the NMOS tube M6 is connected to the source of the NMOS tube M5.

2. The battery charge and discharge management system according to claim 1, characterized in that: The switched capacitor voltage converter is a switched capacitor voltage converter with a forward 1:2 boost and a reverse 2:1 buck.

3. The battery charge and discharge management system according to claim 1, characterized in that: In the step-down voltage converter, the NMOS tube M1 is used as an isolation switch; the NMOS tubes M2 and M3 are used as power switches; and the NMOS tube M4 is used as a power management switch.

4. The battery charge and discharge management system according to claim 1, characterized in that: In the switched capacitor voltage converter, the NMOS transistors M7 to M14 are used as power switches.

5. The battery charge and discharge management system according to claim 1, characterized in that: In the switch tube converter, the NMOS tubes M5 and M6 are used as high-voltage direct charging switches.

6. The battery charge and discharge management system according to claim 1, characterized in that: The single-cell connection V1X is connected to a single-cell battery; the double-cell connection V2X is connected to a double-cell battery.

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