Mobile terminal and charging circuit of standby battery thereof

Abstract

The utility model relates to a mobile terminal and a charging circuit of a standby battery thereof. The charging circuit comprises a main control module and a charging module, and further comprises a first detection module which is connected with a standby battery and the main control module and used for detecting whether the voltage of the standby battery is lower than a first preset voltage value and outputting a first detection signal to the main control module. The second detection module is connected with the standby battery and the main control module and used for detecting whether the voltage of the standby battery is higher than a second preset voltage value and outputting a second detection signal to the main control module, and the second preset voltage value is larger than the first preset voltage value. And the control output end of the main control module is also connected with the control input end of the switching tube module, and inputs a corresponding turn-on or turn-off control signal to the switching tube module according to the states of the first detection signal and the second detection signal. According to the utility model, the standby battery can be charged stably and safely, the normal operation of equipment is ensured, and the production cost is saved.

Description

Technical Field

[0001] The utility model relates to the field of charging circuits, in particular to a charging circuit of a mobile terminal and a backup battery thereof. Background Art

[0002] With the development of warehousing and express delivery, many application scenarios require hot swapping. The so-called hot swapping means that after unplugging the main battery of the mobile terminal, the power supply continues to be supplied to the device to keep the time of the mobile terminal from being lost or some programs continue to run, that is, the mobile terminal is required to work uninterruptedly for a long time. However, since the capacity of the main battery is limited and cannot meet the uninterrupted working requirements, a backup battery is required to continue to power the mobile terminal immediately after the main battery loses power. However, the charging circuit for charging the backup battery in the related art is costly, and the safety and stability of the charging process are low. Utility Model Content

[0003] The technical problem to be solved by the utility model is to provide a charging circuit for a mobile terminal and a backup battery thereof.

[0004] The technical solution adopted by the utility model to solve the technical problem is: a charging circuit for a backup battery of a mobile terminal, including a main control module and a charging module, and also including:

[0005] A first detection module connected to the backup battery and the main control module, and configured to detect whether the voltage of the backup battery is lower than a first preset voltage value and output a first detection signal to the main control module;

[0006] A second detection module connected to the backup battery and the main control module, used to detect whether the voltage of the backup battery is higher than a second preset voltage value and output a second detection signal to the main control module, wherein the second preset voltage value is greater than the first preset voltage value;

[0007] A switch tube module connected between the system power supply and the charging module;

[0008] The control output end of the main control module is also connected to the control input end of the switch tube module, and inputs a corresponding on or off control signal to the switch tube module according to the status of the first detection signal and the second detection signal, so that the switch tube module realizes the on or off between the system power supply and the charging module.

[0009] Furthermore, in the charging circuit of the mobile terminal backup battery described in the utility model, the switching tube module includes a MOS tube Q1 and a transistor Q2, the source of the MOS tube Q1 is connected to the system power supply and connected to the collector of the transistor Q2 via a resistor R4, the gate of the MOS tube Q1 is connected to the collector of the transistor Q2, the drain of the MOS tube Q1 is connected to the charging module and grounded via a capacitor C3, the base of the transistor Q2 is connected to the control output end of the main control module via a resistor R11 and grounded via a resistor R12, and the emitter of the transistor Q2 is grounded.

[0010] Furthermore, in the charging circuit of the mobile terminal backup battery described in the utility model, the first detection module includes a first detection chip, the first pin of the first detection chip is connected to the first detection signal input end of the main control module, and is connected to the working power supply via resistor R1, the third pin and the fourth pin of the first detection chip are connected to the backup battery and are grounded via capacitor C7, and the fifth pin of the first detection chip is grounded via capacitor C6.

[0011] Furthermore, in the charging circuit of the mobile terminal backup battery described in the utility model, the second detection module includes a fifth detection chip, the first pin of the fifth detection chip is connected to the second detection signal input terminal of the main control module, and is connected to the working power supply via resistor R13, the third pin and the fourth pin of the fifth detection chip are connected to the backup battery and are grounded via capacitor C12, and the fifth pin of the fifth detection chip is grounded via capacitor C13.

[0012] Further, in the charging circuit of the backup battery of the mobile terminal described in the utility model, the main control module is used to input a corresponding conduction control signal to the switch tube module when the first detection module detects that the voltage of the backup battery is lower than the first preset voltage value and the state of the first detection signal changes from a low level signal to a high level signal, so that the switch tube module realizes conduction between the system power supply and the charging module;

[0013] The main control module is used to input a corresponding shutdown control signal to the switch tube module when the second detection module detects that the voltage of the backup battery is higher than the second preset voltage value and the state of the second detection signal changes from a high-level signal to a low-level signal, so that the switch tube module can realize the shutdown between the system power supply and the charging module.

[0014] Furthermore, in the charging circuit of the mobile terminal backup battery described in the utility model, the charging module includes a charging IC, and a DCDC boost module connected to the switch tube module and the charging IC and used to boost the system power supply to a third preset voltage value.

[0015] Furthermore, in the charging circuit of the backup battery of the mobile terminal described in the utility model, the charging module also includes an over-discharge protection module connected to the charging IC and the backup battery.

[0016] Furthermore, in the charging circuit of the backup battery of the mobile terminal described in the utility model, the main control module is also used to output an I2C signal to the charging IC to set the charging voltage of the backup battery.

[0017] Further, in the charging circuit of the backup battery of the mobile terminal described in the utility model, the backup battery is a lithium-ion supercapacitor; or

[0018] The first preset voltage value is 3.6V, and the second preset voltage value is 3.8V.

[0019] In addition, the utility model also provides a mobile terminal, including a main battery and a system power supply, and also including a charging circuit connected to the system power supply, such as the above-mentioned mobile terminal backup battery.

[0020] The mobile terminal and the charging circuit of the backup battery thereof implementing the utility model have the following beneficial effects: the charging circuit of the present application monitors the voltage of the backup battery in real time through two voltage detection modules to determine whether to charge the backup battery. The charging circuit can be generally used in mobile terminals, and can charge the backup battery stably and safely, ensuring the normal operation of the equipment while saving production costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The present invention will be further described below with reference to the accompanying drawings and embodiments, in which:

[0022] Figure 1 It is a structural schematic diagram of a charging circuit of a backup battery of a mobile terminal according to an embodiment of the present application;

[0023] Figure 2 is a schematic diagram of the structure of a charging circuit of a backup battery of a mobile terminal in some embodiments of the present application;

[0024] Figure 3 is a schematic diagram of the structure of a charging circuit of a backup battery of a mobile terminal in some embodiments of the present application;

[0025] Figure 4 This is a circuit diagram of a charging circuit for a mobile terminal backup battery in some embodiments of the present application.

[0026] Description of reference numerals:

[0027] 10. Main control module; 20. Charging module; 30. First detection module; 40. Second detection module; 50. Switch tube module; 60. System power supply; 70. Backup battery; 201. Charging IC; 202. DCDC boost module; 203. Over-discharge protection module. DETAILED DESCRIPTION

[0028] In order to have a clearer understanding of the technical features, purposes and effects of the present utility model, the specific implementation methods of the present utility model are now described in detail with reference to the accompanying drawings.

[0029] In the following description, specific details such as specific system structures and technologies are provided for the purpose of illustration rather than limitation, so as to provide a thorough understanding of the embodiments of the present invention. However, it should be clear to those skilled in the art that the present invention can also be implemented in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, circuits, and methods are omitted to avoid unnecessary details that hinder the description of the present invention.

[0030] In order to facilitate the understanding of the present invention, the present invention will be described more comprehensively below. The present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present invention more thorough and comprehensive.

[0031] It should be understood that although the terms first, second, third, etc. may be used to describe various information in the present embodiment, these information should not be limited to these terms. These terms are only used to distinguish the same type of information from each other. It is not necessarily required or implied that there is any such actual relationship or order between these entities or operations.

[0032] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention.

[0033] refer to Figure 1 An embodiment of the present application discloses a charging circuit for a mobile terminal backup battery 70, including a main control module 10 and a charging module 20, and further including:

[0034] The first detection module 30 is connected to the backup battery 70 and the main control module 10 and is used to detect whether the voltage of the backup battery 70 is lower than a first preset voltage value and output a first detection signal to the main control module 10 .

[0035] A second detection module 40 connected to the backup battery 70 and the main control module 10, for detecting whether the voltage of the backup battery 70 is higher than a second preset voltage value and outputting a second detection signal to the main control module 10, wherein the second preset voltage value is greater than the first preset voltage value. Preferably, the first preset voltage value is 3.6V and the second preset voltage value is 3.8V.

[0036] The switch module 50 is connected between the system power supply 60 and the charging module 20 .

[0037] The control output end of the main control module 10 is also connected to the control input end of the switch tube module 50, and inputs a corresponding on or off control signal to the switch tube module 50 according to the state of the first detection signal and the second detection signal, so that the switch tube module 50 realizes the on or off between the system power supply 60 and the charging module 20.

[0038] Alternatively, the backup battery 70 is a lithium-ion supercapacitor or the like.

[0039] The working principle of the utility model is: when the first detection module 30 detects that the voltage of the backup battery 70 is lower than the first preset voltage value, the state of the output first detection signal changes from a low-level signal to a high-level signal, and at this time the main control module 10 inputs a corresponding conduction control signal to the switch tube module 50, and then the switch tube module 50 realizes the conduction between the system power supply 60 and the charging module 20. When the second detection module 40 detects that the voltage of the backup battery 70 is higher than the second preset voltage value, the state of the second detection signal changes from a high-level signal to a low-level signal, and at this time the main control module 10 inputs a corresponding shutdown control signal to the switch tube module 50, and then the switch tube module 50 realizes the shutdown between the system power supply 60 and the charging module 20.

[0040] Of course, the state of the first detection signal and the state of the second detection signal can be interchanged, which is not specifically limited in this application.

[0041] The charging circuit of this embodiment monitors the voltage of the backup battery 70 in real time through two voltage detection modules to determine whether to charge the backup battery. The charging circuit can be generally used in mobile terminals, and can charge the backup battery 70 stably and safely, ensuring the normal operation of the equipment while saving production costs.

[0042] In some embodiments, Figure 4As shown, the switch tube module 50 includes a MOS tube Q1 and a transistor Q2, the source of the MOS tube Q1 is connected to the system power supply 60, and is connected to the collector of the transistor Q2 via a resistor R4, the gate of the MOS tube Q1 is connected to the collector of the transistor Q2, the drain of the MOS tube Q1 is connected to the charging module 20, and is grounded via a capacitor C3, the base of the transistor Q2 is connected to the control output end of the main control module 10 via a resistor R11, and is grounded via a resistor R12, and the emitter of the transistor Q2 is grounded.

[0043] like Figure 4 As shown, the first detection module 30 includes a first detection chip U1, a first pin of the first detection chip U1 is connected to the first detection signal input terminal of the main control module 10, and is connected to the working power supply through a resistor R1, a third pin and a fourth pin of the first detection chip U1 are connected to the backup battery 70, and are grounded through a capacitor C7, and a fifth pin of the first detection chip U1 is grounded through a capacitor C6. The second pin of the first detection chip U1 is grounded.

[0044] The second detection module 40 includes a second detection chip U5, a first pin of the second detection chip U5 is connected to the second detection signal input terminal of the main control module 10, and is connected to the working power supply via a resistor R13, a third pin and a fourth pin of the second detection chip U5 are connected to the backup battery 70, and are grounded via a capacitor C12, and a fifth pin of the second detection chip U5 is grounded via a capacitor C13. The second pin of the first detection chip U1 is grounded.

[0045] As an option, the chip model of the first detection chip U1 and the second detection chip U5 is SGM803-SXN3L-TR. Of course, it can also be other detection chip models in the prior art, as long as the corresponding functions of the detection chip in this application can be achieved, and this application does not make specific restrictions.

[0046] In some embodiments, Figure 2 As shown, the charging module 20 includes a charging IC 201, and a DCDC boost module 202 connected to the switch tube module 50 and the charging IC 201, and used to boost the system power 60 to a third preset voltage value. As an option, the main control module 10 is also used to output an I2C signal to the charging IC 201 to set the charging voltage of the backup battery 70. In this embodiment, by setting a DCDC boost module 202 between the switch tube module 50 and the charging IC 201, it is possible to avoid the situation where the backup battery 70 cannot be charged when the main battery of the device is low in power, and the charging voltage of the backup battery can be flexibly set through I2C.

[0047] Alternatively, if Figure 3As shown, the charging module 20 also includes an over-discharge protection module 203 connected to the charging IC 201 and the backup battery 70. In this embodiment, an over-discharge protection module 203 is provided between the charging IC 201 and the backup battery 70 to further make the charging process safe and stable. In this embodiment, the charging voltage of the backup battery 70 can be set to 3.8V. Of course, the corresponding charging voltage can also be set according to user needs and the specification configuration of the backup battery 70, which is not specifically limited here.

[0048] Combination Figure 4 , the working principle of the charging circuit of the backup battery 70 of the mobile terminal of the utility model is further explained. The utility model uses two voltage detection chips U1 and U5 to monitor the voltage of the backup battery 70 in real time. Under normal charging conditions, the control output terminal GPIO1 pin of the main control module 10 outputs a high level. At this time, the transistor Q2 is turned on, thereby turning on the MOS tube Q1, so that the system power supply 60 (such as Figure 4 The VPH_PWR (approximately the main battery voltage) passes through the MOS tube Q1 and the DCDC boost module 202 to be boosted to 5V, which can prevent the backup battery 70 from being unable to charge when the main battery of the device is low on power. Finally, it enters the charging IC 201 to charge the backup battery 70.

[0049] When it is detected that the voltage of the backup battery 70 exceeds 3.8V, the second detection signal output by the second detection chip U5 changes from a high level to a low level to notify the CPU that the backup battery 70 is overcharged; the GPIO1 output changes from a high level to a low level, so that the transistor Q2 is turned off, the MOS tube Q1 is turned off, and the charging of the backup battery 70 stops.

[0050] When the voltage of the backup battery 70 is detected to be lower than 3.6V (for example, the circuit consumes power by itself), the first detection signal output by the first detection chip U1 changes from a low level to a high level to notify the CPU that the backup battery 70 needs to be recharged, and the GPIO1 output changes from low to high. At this time, the transistor Q2 is turned on, the MOS tube Q1 is turned on, and the backup battery 70 is recharged.

[0051] This embodiment uses common materials to design the circuit, and the material packaging is common, the circuit cost is low, and a large amount of design cost and time can be saved for engineers.

[0052] like Figure 4As shown, the main control module 10 includes a fourth chip U4, the charging IC 201 includes a second chip U2, the DCDC boost module 202 includes a third chip U3, a resistor R5 and a resistor group R9, the drain of the MOS tube Q1 is connected to the fourth pin of the third chip U3, and is connected to the sixth pin of the third chip U3 through the inductor L1, the third pin of the third chip U3 is connected to one end of the resistor R6, the other end of the resistor R6 is connected to the drain of the MOS tube Q1, and is grounded through the capacitor C8, the first pin of the third chip U3 is connected to the A1 pin of the second chip U2, and is grounded through the resistor R7 and the resistor R10, and is grounded through the capacitor C9 and the capacitor C10 respectively, and the fifth pin of the third chip U3 is connected between the resistor R7 and the resistor R10.

[0053] The C1 pin of the second chip U2 is connected to the SDA pin of the fourth chip U4, and is connected to the working power supply through the resistor R3. The C2 pin of the second chip U2 is connected to the SCL pin of the fourth chip U4, and is connected to the working power supply through the resistor R2. The main control module 10 outputs an I2C signal to the charging IC 201 through the SDA and SCL pins to set the charging voltage of the backup battery 70. The connection point between the second end of the resistor R5 and the second end of the resistor group R9 is connected to the B1 pin of the second chip U2, and is grounded through the resistor R8. The first end of the resistor R5 is connected to the B3 pin of the second chip U2, and is grounded through the capacitor C11. The first end of the resistor group R9 is connected to the C3 pin of the second chip U2 and is grounded. The A2 pin of the second chip U2 is connected to the system voltage and is grounded through the capacitor C1.

[0054] The over-discharge protection module 203 includes a sixth chip U6 and a resistor R14, wherein the first end of the resistor R14 is connected to the fourth pin of the sixth chip U6, and is connected to the first pin and the second pin of the sixth chip U6 via the capacitor C15, the second end of the resistor R14 is connected to the A3 pin of the second chip U2 of the charging IC 201, and is grounded via the capacitor C14, the third pin and the fourth pin of the first detection chip U1 are connected to the common terminal of the capacitor C14 and the resistor R14, and the third pin and the fourth pin of the second detection chip U5 are also connected to the common terminal of the capacitor C14 and the resistor R14. In this embodiment, the capacitor C14 is the backup battery 70, preferably a polarized capacitor with a specification of 3.8V / 100F.

[0055] As an option, the chip model of the charging IC 201 is ETA4662. Of course, it can also be other charging IC 201 chip models in the prior art, as long as the corresponding functions of the charging IC 201 of this application can be realized, and no specific limitation is made here. The chip signal of the DCDC boost module 202 is ETA1038. Of course, it can also be other DCDC chip models in the prior art, as long as the corresponding functions of the charging IC 201 of this application can be realized, and no specific limitation is made here. The chip signal of the over-discharge protection module 203 is FH8206. Of course, it can also be other over-discharge protection chip models in the prior art, and no specific limitation is made here.

[0056] It should be noted that the main control module 10 can select a corresponding module or chip in the prior art, which will not be described in detail here. The working power supply in this application is 1.8V, and the specific working power supply voltage of each circuit module can also be configured according to the actual chip selection, which is not specifically limited here.

[0057] The charging circuit of this embodiment monitors the voltage of the backup battery 70 in real time through two voltage detection modules to determine whether to charge the backup battery. The charging circuit can be generally used in mobile terminals, and can charge the backup battery 70 stably and safely, ensuring the normal operation of the equipment while saving production costs.

[0058] In another preferred embodiment, the mobile terminal of this embodiment includes a main battery, a backup battery 70 , a system power supply 60 , and a charging circuit of the mobile terminal backup battery 70 of the above embodiment connected to the system power supply 60 and the backup battery 70 .

[0059] It should be noted that the mobile terminal of this embodiment may be a broad range of mobile terminals including POS machines, vehicle-mounted computers, notebooks, mobile phones, etc.

[0060] The mobile terminal of this embodiment includes a charging circuit that monitors the voltage of the backup battery 70 in real time through two voltage detection modules to determine whether to charge, which can enable the backup battery 70 to be charged stably and safely, ensuring the normal operation of the device while saving production costs.

[0061] Professionals may further appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of the two. In order to clearly illustrate the interchangeability of hardware and software, the composition and steps of each example have been generally described in the above description according to function. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professionals and technicians may use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of the present utility model.

[0062] It can be understood that the above embodiments only express the preferred implementation methods of the utility model, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the patent scope of the utility model. It should be pointed out that, for ordinary technicians in this field, without departing from the concept of the utility model, the above-mentioned technical features can be freely combined, and several deformations and improvements can be made, which all belong to the protection scope of the utility model. Therefore, all equivalent changes and modifications made to the scope of the claims of the utility model should belong to the scope covered by the claims of the utility model.

Claims

1. A charging circuit for a backup battery of a mobile terminal, comprising a main control module (10) and a charging module (20), characterized in that: Also includes: A first detection module (30) connected to the backup battery (70) and the main control module (10), used to detect whether the voltage of the backup battery (70) is lower than a first preset voltage value and output a first detection signal to the main control module (10); a second detection module (40) connected to the backup battery (70) and the main control module (10), and used for detecting whether the voltage of the backup battery (70) is higher than a second preset voltage value and outputting a second detection signal to the main control module (10), wherein the second preset voltage value is greater than the first preset voltage value; A switch tube module (50) connected between a system power supply (60) and the charging module (20); The control output end of the main control module (10) is also connected to the control input end of the switch tube module (50), and inputs a corresponding on or off control signal to the switch tube module (50) according to the states of the first detection signal and the second detection signal, so that the switch tube module (50) realizes the on or off between the system power supply (60) and the charging module (20).

2. The charging circuit of the mobile terminal backup battery according to claim 1, characterized in that: The switch tube module (50) comprises a MOS tube Q1 and a transistor Q2, the source of the MOS tube Q1 is connected to the system power supply (60) and connected to the collector of the transistor Q2 via a resistor R4, the gate of the MOS tube Q1 is connected to the collector of the transistor Q2, the drain of the MOS tube Q1 is connected to the charging module (20) and is grounded via a capacitor C3, the base of the transistor Q2 is connected to the control output end of the main control module (10) via a resistor R11 and is grounded via a resistor R12, and the emitter of the transistor Q2 is grounded.

3. The charging circuit of the mobile terminal backup battery according to claim 1, characterized in that: The first detection module (30) comprises a first detection chip, wherein a first pin of the first detection chip is connected to a first detection signal input terminal of the main control module (10) and is connected to a working power supply via a resistor R1, a third pin and a fourth pin of the first detection chip are connected to the backup battery (70) and are grounded via a capacitor C7, and a fifth pin of the first detection chip is grounded via a capacitor C6.

4. The charging circuit of the mobile terminal backup battery according to claim 1, characterized in that: The second detection module (40) comprises a fifth detection chip, wherein a first pin of the fifth detection chip is connected to a second detection signal input terminal of the main control module (10) and is connected to a working power supply via a resistor R13, a third pin and a fourth pin of the fifth detection chip are connected to the backup battery (70) and are grounded via a capacitor C12, and a fifth pin of the fifth detection chip is grounded via a capacitor C13.

5. The charging circuit of the mobile terminal backup battery according to claim 1, characterized in that: The main control module (10) is used for inputting a corresponding conduction control signal to the switch tube module (50) when the first detection module (30) detects that the voltage of the backup battery (70) is lower than the first preset voltage value and the state of the first detection signal changes from a low-level signal to a high-level signal, so that the switch tube module (50) realizes conduction between the system power supply (60) and the charging module (20); The main control module (10) is used to input a corresponding shutdown control signal to the switch tube module (50) when the second detection module (40) detects that the voltage of the backup battery (70) is higher than the second preset voltage value and the state of the second detection signal changes from a high-level signal to a low-level signal, thereby realizing the shutdown between the system power supply (60) and the charging module (20) by the switch tube module (50).

6. The charging circuit of the mobile terminal backup battery according to claim 1, characterized in that: The charging module (20) comprises a charging IC (201), and a DCDC boost module (202) connected to the switch tube module (50) and the charging IC (201) and used for boosting the system power supply (60) to a third preset voltage value.

7. The charging circuit of the mobile terminal backup battery according to claim 6, characterized in that: The charging module (20) further comprises an over-discharge protection module (203) connected to the charging IC (201) and the backup battery (70).

8. The charging circuit of the mobile terminal backup battery according to claim 6, characterized in that: The main control module (10) is also used to output an I2C signal to the charging IC (201) for setting the charging voltage of the backup battery (70).

9. The charging circuit of the mobile terminal backup battery according to any one of claims 1 to 8, characterized in that: The backup battery (70) is a lithium-ion supercapacitor; or The first preset voltage value is 3.6V, and the second preset voltage value is 3.8V.

10. A mobile terminal, comprising a main battery and a system power supply (60), characterized in that: It also includes a charging circuit for the backup battery of the mobile terminal according to any one of claims 1 to 9, which is connected to the system power supply (60).

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