Control circuit and control method applied to low-voltage area of lithium battery

Abstract

The invention relates to the technical field of lithium batteries, and discloses a control circuit and a control method applied to a low-voltage area of a lithium battery. The control method comprises the steps that the battery module obtains a power supply output signal and outputs current, and the control system judges the output voltage of the battery module; when the output voltage is within a first preset range value, the output voltage is output to a mainboard PMU chip; the mainboard PMU chip boosts the voltage, outputs the boosted voltage to the first diode unit, and then inputs the boosted voltage to a power utilization system; when the output voltage is within a second preset range value, the output voltage is output to the external control chip; and the external control chip boosts the voltage, outputs the boosted voltage to the second diode unit, and then inputs the boosted voltage to the power utilization system. According to the control method, the output current of the positive electrode of the battery module is divided into two paths to be input into the internal boosting module or the external boosting module, and the low-voltage area of the lithium battery is developed and utilized by designing an application circuit of the low-voltage area of the lithium battery, namely the external boosting module, so that resource waste is reduced and the endurance time of the battery is prolonged.

Description

Technical Field

[0001] The present application relates to the technical field of lithium batteries, and in particular to a control circuit and a control method applied to a low-voltage zone of a lithium battery. Background Art

[0002] At present, lithium batteries are mainly used in electronic products, power batteries, energy storage and aviation. Generally speaking, the standard voltage range of lithium batteries is 2.5V to 4.2V. Within this range, the battery voltage will gradually decrease as the discharge progresses. When the battery voltage drops below 2.5V, the discharge will terminate; and when the battery voltage exceeds 4.2V, the charging circuit will stop to protect the battery voltage safety. Therefore, when using lithium batteries, it is necessary to strictly control their operating voltage range to ensure the safety and performance of the battery.

[0003] However, in many usage scenarios, the low-voltage area of ​​lithium batteries is often not utilized. This is because the operating voltage of the PMU (power management chip) of many current SOC (System on Chip) platforms cannot be lower than 3.4V, which results in the voltage in the low-voltage area of ​​lithium batteries not being utilized, resulting in a short battery life. Summary of the invention

[0004] The technical problem to be solved by the present application is to design an application circuit for the low-voltage area of ​​a lithium battery, develop and utilize the low-voltage area of ​​the lithium battery, thereby reducing resource waste and extending battery life.

[0005] In the first aspect, an embodiment of the present invention discloses a control method applied to a low-voltage area of ​​a lithium battery, and a control circuit applied to a low-voltage area of ​​a lithium battery, wherein the control circuit is electrically connected to a control system, the control circuit includes a battery module, an internal boost module and an external boost module, the internal boost module includes a mainboard PMU chip and a first diode unit, the positive electrode of the battery module is connected to the mainboard PMU chip, and the first diode unit is respectively connected to the mainboard PMU chip and the power system; the external boost module includes an external control chip and a second diode unit, the positive electrode of the battery module is connected to the external control chip, and the second diode unit is respectively connected to the external control chip and the power system;

[0006] The control method comprises:

[0007] The battery module obtains a power supply output signal and outputs a current, and the control system determines an output voltage of the battery module;

[0008] When the output voltage is within a first preset range, it is output to the mainboard PMU chip;

[0009] The mainboard PMU chip boosts the voltage and outputs it to the first diode unit, and then inputs it into the power system;

[0010] When the output voltage is within a second preset range, outputting to the external control chip;

[0011] The external control chip boosts the voltage and outputs it to the second diode unit, and then inputs it into the power consumption system.

[0012] Preferably, the first preset range value is that the output voltage is greater than 3.8V.

[0013] Preferably, the second preset range value is that the output voltage is between 2.5V and 3.8V.

[0014] In the second aspect, an embodiment of the present invention further discloses a control circuit applied to a low-voltage zone of a lithium battery, wherein the control circuit applies the control method applied to a low-voltage zone of a lithium battery as described in the first aspect above, and the control circuit includes a battery module, an internal boost module and an external boost module; the internal boost module includes a mainboard PMU chip and a first diode unit, the positive pole of the battery module is connected to the fourth pin and the fifth pin of the mainboard PMU chip, one end of the first diode unit is respectively connected to the output pins of the mainboard PMU chip, and the other end of the first diode unit is output to the power consumption system; the external boost module includes an external control chip and a second diode unit, the positive pole of the battery module is connected to the fourth pin of the external control chip, one end of the second diode unit is respectively connected to the output pins of the external control chip, and the other end of the second diode unit is output to the power consumption system.

[0015] Preferably, the first diode unit includes a first MOS tube group and a first composite PNP chip, the output pin of the mainboard PMU chip is connected to the input pin of the first MOS tube group and the first pin of the first composite PNP chip, and the output pin of the first MOS tube group and the fourth pin of the first composite PNP chip are respectively output to the power consumption system.

[0016] Preferably, the second diode unit includes a third MOS tube group and a second composite PNP chip, the output pin of the external control chip is connected to the input pin of the third MOS tube group and the first pin of the second composite PNP chip, and the output pin of the third MOS tube group and the fourth pin of the second composite PNP chip are respectively output to the power consumption system.

[0017] Preferably, the internal boost module also includes a fifth MOS tube group, a first connection end of the fifth MOS tube group is connected to the fourth pin and the fifth pin of the mainboard PMU chip, a second connection end of the fifth MOS tube group is connected to the third pin of the mainboard PMU chip, and a third connection end of the fifth MOS tube group is output to the first diode unit.

[0018] Preferably, the internal boost module further includes a first resistor, one end of the first resistor is connected to the fourth pin and the fifth pin of the mainboard PMU chip, and the other end of the first resistor is connected to the third pin of the mainboard PMU chip.

[0019] Preferably, the external boost module further includes a first inductor, one end of the first inductor is connected to the positive electrode of the battery module, and the other end of the first inductor is connected to the first pin and the second pin of the external control chip.

[0020] Compared with the prior art, the present invention has at least one of the following beneficial technical effects:

[0021] The control method of the present application divides the output current of the positive electrode of the battery module into two paths and inputs it into the internal boost module or the external boost module. When the control system detects and determines that the output voltage of the battery module is in the first preset range value, the external boost module is cut off, the internal boost module is turned on, and the current is output to the mainboard PMU chip. The voltage is boosted by the high-voltage boost circuit set in the mainboard PMU chip to obtain the output voltage VCC-SYS, and then the power supply system is powered by the first diode unit. When the control system detects and determines that the output voltage of the battery module is in the second preset range value, the internal boost module is cut off, the external boost module is turned on, and the current is output to the external control chip. The voltage is boosted by the low-voltage boost circuit of the external control chip to obtain a 3.8V output voltage VBAT, and then the power supply system VCC_SYS is powered by the second diode unit. In this regard, by designing the application circuit of the low-voltage area of ​​the lithium battery, that is, the external boost module, the low-voltage area of ​​the lithium battery is developed and utilized, thereby reducing resource waste and extending the battery life. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0023] Figure 1 This is a flow chart of a control method for a lithium battery low voltage zone in an embodiment of the present application.

[0024] Figure 2Schematic diagram of the partial circuit structure of the internal boost module in the control circuit applied to the low-voltage area of ​​the lithium battery in the embodiment of the present application.

[0025] Figure 3 Schematic diagram of the circuit structure of the first diode unit in the control circuit applied to the low-voltage area of ​​the lithium battery in the embodiment of the present application.

[0026] Figure 4 Schematic diagram of the partial circuit structure of the external boost module in the control circuit applied to the low-voltage area of ​​the lithium battery in the embodiment of the present application.

[0027] Figure 5 Schematic diagram of the circuit structure of the second diode unit in the control circuit applied to the low-voltage area of ​​the lithium battery in the embodiment of the present application.

[0028] Explanation of the reference numerals: U1, mainboard PMU chip; U2, external control chip; Q1, first MOS tube group; Q2, first composite PNP chip; Q3, third MOS tube group; Q4, second composite PNP chip; Q5, fifth MOS tube group; R1, first resistor; L1, first inductor. DETAILED DESCRIPTION

[0029] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0030] It should be understood that when used in this specification and the appended claims, the terms "include" and "comprises" indicate the presence of described features, integers, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or combinations thereof.

[0031] It should also be understood that the terms used in this application specification are only for the purpose of describing specific embodiments and are not intended to limit the application. As used in this application specification and the appended claims, the singular forms "a", "an" and "the" are intended to include plural forms unless the context clearly indicates otherwise.

[0032] It should be further understood that the term “and / or” used in the specification and appended claims refers to any combination and all possible combinations of one or more of the associated listed items, and includes these combinations.

[0033] Please refer to Figures 1 to 5, the embodiment of the present application provides a control method applied to the low-voltage area of ​​lithium batteries, and the control method is applied to the control circuit of the low-voltage area of ​​lithium batteries. Among them, the control circuit is electrically connected to the control system, and the control circuit includes a battery module, an internal boost module and an external boost module. The internal boost module includes a mainboard PMU chip U1 and a first diode unit. The positive pole of the battery module is connected to the mainboard PMU chip U1, and the first diode unit is respectively connected to the mainboard PMU chip U1 and the power system; the external boost module includes an external control chip U2 and a second diode unit. The positive pole of the battery module is connected to the external control chip U2, and the second diode unit is respectively connected to the external control chip U2 and the power system.

[0034] The control method disclosed in this application is a control method applied to the low-voltage area of ​​a lithium battery. Figure 1 As shown, the control method includes steps S110 to S150.

[0035] S110, the battery module obtains a power supply output signal and outputs a current, and the control system determines an output voltage of the battery module.

[0036] When the battery module obtains the power supply output signal from the control system, the positive electrode of the battery module outputs the current VCC_BAT+. At this time, the control system determines the output voltage of the battery module so as to divide the current into two paths and input it into the internal boost module or the external boost module.

[0037] S120: When the output voltage is within the first preset range, output it to the mainboard PMU chip U1.

[0038] When the control system detects and determines that the output voltage of the battery module is within the first preset range, the external boost module is turned off, the internal boost module is turned on, and the current is output to the mainboard PMU chip U1.

[0039] In a specific embodiment, the first preset range value is an output voltage greater than 3.8 V. At this time, the current is output to the high-voltage boost circuit provided in the motherboard PMU chip U1 for boosting. In other embodiments, the first preset range value can also be an output voltage in other ranges.

[0040] S130, the mainboard PMU chip U1 boosts the voltage and outputs it to the first diode unit, and then inputs it into the power system.

[0041] The output current VCC_BAT+ of the positive electrode of the battery module is input into the mainboard PMU chip U1, and the voltage is boosted by the high-voltage boost circuit provided in the mainboard PMU chip U1 to obtain the output voltage VCC-SYS, which is then powered to the power system VCC_SYS through the first diode unit.

[0042] S140: When the output voltage is within the second preset range, output it to the external control chip U2.

[0043] When the control system detects and determines that the output voltage of the battery module is within the second preset range, the internal boost module is turned off, the external boost module is turned on, and the current is output to the external control chip U2.

[0044] In a specific embodiment, the second preset range value is an output voltage of 2.5V to 3.8V. At this time, the current is output to the low-voltage boost circuit of the external control chip U2 for boosting, thereby utilizing the low-voltage area of ​​the lithium battery. In other embodiments, the second preset range value can also be an output voltage in other ranges.

[0045] S150, the external control chip U2 boosts the voltage and outputs it to the second diode unit, and then inputs it into the power system.

[0046] The output current VCC_BAT+ of the positive electrode of the battery module is input to the external control chip U2, and the voltage is boosted by the low-voltage boost circuit of the external control chip U2 to obtain a 3.8V VBAT voltage, which is then supplied to the power system VCC_SYS through the second diode unit. In other embodiments, the VBAT voltage can also be other values.

[0047] Therefore, the control method of the embodiment of the present application divides the output current VCC_BAT+ of the positive electrode of the battery module into two paths and inputs it into the internal boost module or the external boost module. When the control system detects and determines that the output voltage of the battery module is in the first preset range value, the external boost module is turned off, the internal boost module is turned on, and the current is output to the mainboard PMU chip U1, and the voltage is boosted by the high-voltage boost circuit set in the mainboard PMU chip U1 to obtain the output voltage VCC-SYS, and then the power system VCC_SYS is powered by the first diode unit. When the control system detects and determines that the output voltage of the battery module is in the second preset range value, the internal boost module is turned off, the external boost module is turned on, and the current is output to the external control chip U2, and the voltage is boosted by the low-voltage boost circuit of the external control chip U2 to obtain a 3.8V output voltage VBAT, and then the power system VCC_SYS is powered by the second diode unit. In this regard, by designing the application circuit of the low-voltage area of ​​the lithium battery, that is, the external boost module, the low-voltage area of ​​the lithium battery is developed and utilized, thereby reducing resource waste and extending the battery life.

[0048] Please refer to Figures 2 to 5 The embodiment of the present invention also discloses a control circuit applied to a low-voltage area of ​​a lithium battery, wherein the control circuit applies the control method applied to a low-voltage area of ​​a lithium battery as in the above embodiment, and the control circuit includes a battery module, an internal boost module and an external boost module.

[0049] Specifically, the internal boost module includes the mainboard PMU chip U1 and the first diode unit, the positive electrode of the battery module is connected to the fourth pin and the fifth pin of the mainboard PMU chip U1, the negative electrode of the battery module is connected to the sixth pin of the mainboard PMU chip U1, one end of the first diode unit is respectively connected to the output pin of the mainboard PMU chip U1, and the other end of the first diode unit is output to the power system VCC_SYS. The external boost module includes the external control chip U2 and the second diode unit, the positive electrode of the battery module is connected to the fourth pin of the external control chip U2, one end of the second diode unit is respectively connected to the output pin of the external control chip U2, and the other end of the second diode unit is output to the power system VCC_SYS.

[0050] When the control system detects and determines that the output voltage of the battery module is within the first preset range, the positive electrode of the battery module is output to the fourth pin and the fifth pin of the mainboard PMU chip U1, and the voltage is boosted by the high-voltage boost circuit in the mainboard PMU chip U1 to obtain the output voltage VCC-SYS, which then flows through the output pin of the PMU chip through the first diode unit to supply power to the power system VCC_SYS. When the control system detects and determines that the output voltage of the battery module is within the second preset range, the positive electrode of the battery module is output to the fourth pin of the external control chip U2, and the voltage is boosted by the low-voltage boost circuit of the external control chip U2, and then flows through the output pin of the external control chip U2 through the second diode unit to supply power to the power system VCC_SYS. In this regard, by designing the application circuit of the low-voltage area of ​​the lithium battery, that is, the external boost module, the low-voltage area of ​​the lithium battery is developed and utilized, thereby reducing resource waste and extending the battery life.

[0051] In a specific embodiment, the first diode unit includes a first MOS tube group Q1 and a first composite PNP chip Q2. The output pin of the mainboard PMU chip U1 is connected to the input pin of the first MOS tube group Q1 and the first pin of the first composite PNP chip Q2, and the output pin of the first MOS tube group Q1 and the fourth pin of the first composite PNP chip Q2 are respectively output to the power system VCC_SYS. In this embodiment, the output pins of the mainboard PMU chip U1 are the second pin and the first pin. The ideal diode circuit unit composed of the first MOS tube group Q1 and the first composite PNP chip Q2 is equivalent to a diode. When the forward current conducts the first diode unit, the voltage drop of the first diode unit is very small or even non-existent; when the reverse current is input, the first diode unit is cut off, and the first diode unit has the function of preventing current backflow.

[0052] In a specific embodiment, the second diode unit includes a third MOS tube group Q3 and a second composite PNP chip Q4. The output pin of the external control chip U2 is connected to the input pin of the third MOS tube group Q3 and the first pin of the second composite PNP chip Q4, and the output pin of the third MOS tube group Q3 and the fourth pin of the second composite PNP chip Q4 are respectively output to the power system VCC_SYS. In this embodiment, the output pins of the external control chip U2 are the ninth pin and the tenth pin. The ideal diode circuit unit composed of the third MOS tube group Q3 and the second composite PNP chip Q4 is equivalent to a diode. When the forward current conducts the second diode unit, the voltage drop of the second diode unit is very small or even zero; when the reverse current is input, the second diode unit is cut off, and the second diode unit has the function of preventing current backflow.

[0053] In a specific embodiment, the internal boost module further includes a fifth MOS tube group Q5, wherein a first connection end of the fifth MOS tube group Q5 is connected to a fourth pin and a fifth pin of the mainboard PMU chip U1, a second connection end of the fifth MOS tube group Q5 is connected to a third pin of the mainboard PMU chip U1, and a third connection end of the fifth MOS tube group Q5 is output to a VCC-SYS interface of the first diode unit.

[0054] In a specific embodiment, the internal boost module further includes a first resistor R1, wherein one end of the first resistor R1 is connected to the fourth pin and the fifth pin of the mainboard PMU chip U1, and is connected to the first connection end of the fifth MOS tube group Q5; the other end of the first resistor R1 is connected to the third pin of the mainboard PMU chip U1, and is connected to the second connection end of the fifth MOS tube group Q5.

[0055] In a specific embodiment, the external boost module further includes a first inductor L1. One end of the first inductor L1 is connected to the positive electrode of the battery module, and the other end of the first inductor L1 is connected to the first pin and the second pin of the external control chip U2. The inductor has the function of hindering current changes and storing electrical energy, thereby improving the working stability of the external boost module.

[0056] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can easily think of various equivalent modifications or replacements within the technical scope disclosed in the present application, and these modifications or replacements should be included in the protection scope of the present application. Therefore, the protection scope of the present application shall be based on the protection scope of the claims.

Claims

1. A control method for a lithium battery in a low-voltage area, and a control circuit for a lithium battery in a low-voltage area, characterized in that: The control circuit is electrically connected to a control system, and the control circuit includes a battery module, an internal boost module and an external boost module, the internal boost module includes a mainboard PMU chip and a first diode unit, the positive electrode of the battery module is connected to the mainboard PMU chip, and the first diode unit is respectively connected to the mainboard PMU chip and the power system; the external boost module includes an external control chip and a second diode unit, the positive electrode of the battery module is connected to the external control chip, and the second diode unit is respectively connected to the external control chip and the power system; The control method comprises: The battery module obtains a power supply output signal and outputs a current, and the control system determines an output voltage of the battery module; When the output voltage is within a first preset range, it is output to the mainboard PMU chip; The mainboard PMU chip boosts the voltage and outputs it to the first diode unit, and then inputs it into the power system; When the output voltage is within a second preset range, outputting to the external control chip; The external control chip boosts the voltage and outputs it to the second diode unit, and then inputs it into the power consumption system.

2. A control method for a lithium battery in a low voltage zone according to claim 1, characterized in that: The first preset range value is that the output voltage is greater than 3.8V.

3. A control method for a lithium battery in a low voltage zone according to claim 1, characterized in that: The second preset range value is that the output voltage is between 2.5V and 3.8V.

4. A control circuit for use in a low-voltage area of ​​a lithium battery according to claim 1, characterized in that: The control circuit applies the control method applied to the low-voltage area of ​​a lithium battery as claimed in any one of claims 1 to 3, and the control circuit includes a battery module, an internal boost module and an external boost module; The internal boost module includes a mainboard PMU chip and a first diode unit, the positive electrode of the battery module is connected to the fourth pin and the fifth pin of the mainboard PMU chip, one end of the first diode unit is respectively connected to the output pins of the mainboard PMU chip, and the other end of the first diode unit is output to the power system; The external boost module includes an external control chip and a second diode unit. The positive pole of the battery module is connected to the fourth pin of the external control chip. One end of the second diode unit is respectively connected to the output pin of the external control chip, and the other end of the second diode unit is output to the power consumption system.

5. A control circuit and control method for a lithium battery in a low voltage area according to claim 4, characterized in that: The first diode unit includes a first MOS tube group and a first composite PNP chip, the output pin of the mainboard PMU chip is connected to the input pin of the first MOS tube group and the first pin of the first composite PNP chip, and the output pin of the first MOS tube group and the fourth pin of the first composite PNP chip are respectively output to the power consumption system.

6. A control circuit and control method for a lithium battery in a low voltage region according to claim 4, characterized in that: The second diode unit includes a third MOS tube group and a second composite PNP chip, the output pin of the external control chip is connected to the input pin of the third MOS tube group and the first pin of the second composite PNP chip, and the output pin of the third MOS tube group and the fourth pin of the second composite PNP chip are respectively output to the power consumption system.

7. A control circuit and control method for a lithium battery in a low voltage area according to claim 4, characterized in that: The internal boost module also includes a fifth MOS tube group, a first connection end of the fifth MOS tube group is connected to the fourth pin and the fifth pin of the mainboard PMU chip, a second connection end of the fifth MOS tube group is connected to the third pin of the mainboard PMU chip, and a third connection end of the fifth MOS tube group is output to the first diode unit.

8. A control circuit and control method for a lithium battery in a low voltage region according to claim 4, characterized in that: The internal boost module further includes a first resistor, one end of which is connected to the fourth pin and the fifth pin of the mainboard PMU chip, and the other end of which is connected to the third pin of the mainboard PMU chip.

9. A control circuit and control method for a lithium battery in a low voltage area according to claim 1, characterized in that: The external boost module further includes a first inductor, one end of which is connected to the positive electrode of the battery module, and the other end of which is connected to the first pin and the second pin of the external control chip.

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