A charging circuit, method and system

Abstract

The present application provides a charging circuit, method and system. The charging circuit includes: a charger, a first control switch, a second control switch, a BTB connector, an active battery switch and a battery; the charger includes: a VBAT pin and a VSYS pin; the VBAT pin is sequentially connected to the first control switch, the first port of the BTB connector, and the first input end of the active battery switch; the VSYS pin is sequentially connected to the second control switch, the first port of the BTB connector, and the first input end of the active battery switch; the output end of the active battery switch is connected to the battery. In this charging circuit, after initially accessing the power supply voltage, VSYS will increase the trickle charge current of the active battery switch to meet the conduction requirement of the active battery switch.

Description

Technical Field

[0001] The present invention relates to the field of chip technology, and in particular to a charging circuit, method and system. Background Art

[0002] Wearable devices have a special stacking architecture. Therefore, after the battery is welded first, the battery will be buckled to the main board through a BTB connector. There are three types of defects during the buckling process: A. Plugging and unplugging with power on damages the main board; B. The power-on timing problem causes some devices to fail self-check. Therefore, an anti-power-on buckling switch is introduced, and an anti-power-on buckling switch is added between the battery and the charger to ensure that the battery is not charged after being buckled to the main board. After the assembly is completed, the power supply is inserted to charge and activate the battery switch. However, when using this method to activate the switch with fast discharge function, the trickle charge current needs to be relatively large, but the battery safety regulations require a small trickle charge current. In the case where the two cannot be balanced, it is difficult for wearable devices to achieve a good charging effect. Summary of the Invention

[0003] The present application provides a charging circuit, method and system to increase the trickle charge current for activating the battery switch and meet the conduction requirement for activating the battery switch.

[0004] In a first aspect, the present application provides a charging circuit, including: a charger, a first control switch, a second control switch, a BTB connector, an activation battery switch and a battery; the charger includes: a VBAT pin and a VSYS pin;

[0005] The VBAT pin is sequentially connected to the first control switch, the first port of the BTB connector, and the first input terminal of the activation battery switch; the VSYS pin is sequentially connected to the second control switch, the first port of the BTB connector, and the first input terminal of the activation battery switch; the output terminal of the activation battery switch is connected to the battery.

[0006] In the present application, after the charger is connected to the power supply voltage, it can provide the voltage required to activate the battery switch through VSYS. By providing the voltage required to activate the battery switch through VSYS, it can ensure a small trickle charge current for VBAT, and at the same time meet the design requirements of VBAT elevation and a small trickle charge current for VBAT. The elevation of VBAT ensures the conduction of the activation battery switch, and the small trickle charge current for VBAT can also ensure compliance with battery safety regulations.

[0007] In an optional manner, the first control switch is a diode; the positive electrode of the first control switch is connected to the VBAT pin, and the negative electrode of the first control switch is connected to the first port of the BTB connector.

[0008] By introducing the first control switch as a diode, leakage of VSYS to VBAT can be prevented.

[0009] In an alternative approach, the second control switch is a diode; the positive electrode of the second control switch is connected to the VSYS pin, and the negative electrode of the second control switch is connected to the first port of the BTB connector.

[0010] By introducing the second control switch that is a diode, leakage of VBAT to VSYS can be prevented, and the impact on VBAT after VSYS power-off can be avoided.

[0011] In an alternative approach, the second port of the BTB connector is respectively connected to the VBAT pin and the second input terminal of the active battery switch.

[0012] In an alternative approach, the first output terminal of the active battery switch is connected to the positive electrode of the battery, and the second output terminal of the active battery switch is connected to the negative electrode of the battery.

[0013] In an alternative approach, the active battery switch includes a first resistor, and the first resistor is used to discharge the voltage at the second output terminal of the active battery switch.

[0014] In a second aspect, the present application provides a charging method, including: the charging circuit receives a power supply voltage; the voltage required for the first input terminal of the active battery switch is provided through the VSYS pin of the charger and the second control switch.

[0015] In the present application, after the charger is connected to the power supply voltage, the voltage required for the active battery switch can be provided through VSYS. By providing the voltage required for the active battery switch through VSYS, a relatively small trickle charging current of VBAT can be ensured, while meeting the design requirements of VBAT elevation and a relatively small trickle charging current of VBAT. The elevation of VBAT ensures the conduction of the active battery switch, and the relatively small trickle charging current of VBAT can also ensure compliance with battery safety regulations.

[0016] In an alternative approach, after the power supply is disconnected, a closed loop is formed by the VBAT pin of the charger, the first control switch, the first port of the BTB connector, the first input terminal of the active battery switch, the second input terminal of the active battery switch, and the second port of the BTB connector.

[0017] In an alternative approach, both the first control switch and the second control switch are diodes.

[0018] In a third aspect, the present application provides a charging system, including the charging circuit of the first aspect and a load circuit.

[0019] For the technical effects that can be achieved in the above second aspect to the third aspect, please refer to the technical effects that can be achieved in the corresponding possible design solutions in the above first aspect. They will not be repeated here in the present application.

[0020] Other features and advantages of the present application will be set forth in the following description, and in part will be obvious from the description, or may be learned by practice of the present application. The objectives and other advantages of the present application may be realized and attained by the structure particularly pointed out in the written description, claims, as well as the drawings. Brief Description of the Drawings

[0021] To more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0022] Figure 1 It is a schematic diagram of a charging circuit;

[0023] Figure 2 It is a schematic diagram of a charging circuit provided by the present application;

[0024] Figure 3 It is a schematic diagram of another charging circuit provided by the present application;

[0025] Figure 4 It is a schematic flowchart of a charging method provided by the present application. Detailed Description of the Embodiments

[0026] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the following clearly and completely describes the technical solutions in the embodiments of the present invention with reference to the drawings in the embodiments of the present invention.

[0027] It should be noted that the terms "first", "second", etc. in the present application are used to distinguish similar objects and do not necessarily describe a specific order or sequence. It should be understood that such data can be interchanged under appropriate circumstances so that the embodiments of the present disclosure described herein can be implemented in an order other than those illustrated or described herein. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present application. On the contrary, they are merely examples of devices and methods consistent with some aspects of the present application as detailed in the appended claims.

[0028] Figure 1 A charging circuit is shown. This charging circuit activates the battery switch through VBAT. The charging circuit includes: a charger, a system load, a coulomb meter, multiple resistors, a BTB connector, an activation battery switch, and a battery. The connections between the components are as Figure 1As shown, the VBAT pin of the charger is connected to a port of the BTB connector through a 100KΩ resistor. The VBAT pin is also connected to another port of the BTB through a 10mΩ resistor. The 10mΩ resistor is also connected to the coulomb meter. In addition, a 4.7uf pull-down capacitor is connected to the VBAT pin. The BTB connector is connected to the VOUT port and the EN port of the active battery switch. A 1MΩ resistor is also connected to the EN port of the active battery switch. The VIN output terminal of the active battery switch is connected to the VBAT+ of the battery (i.e., the positive pole of the battery), and the GND output terminal of the active battery switch is connected to the VBAT- of the battery (i.e., the negative pole of the battery).

[0029] When the battery is connected, since EN is low, the active battery switch is not turned on, VOUT = 0V, and there is no risk of charged buckling. When VBUS (i.e., the power supply voltage) is inserted, since the active battery switch is not turned on in the initial state and the VBAT pin of the charger is 0V, the charger charges the capacitor of the VBAT pin with the magnitude of the trickle charge current (when VBAT < 2V), so that the VBAT terminal is charged to a high level. After VBAT is high, EN is pulled high and the switch is turned on, realizing EN = VOUT = VIN = VBAT+. Even if VBUS is unplugged, EN is always pulled high and the switch is normally turned on.

[0030] However, the conduction condition of the active battery switch is that the charger charges the capacitor of the VBAT pin with the magnitude of the trickle charge current, so that VBAT is charged to a high level. This level should be greater than the minimum value of the high level of EN, which is 1.2V. But because EN is at a low level in the initial state, the fast discharge circuit of the active battery switch is default turned on (i.e., VOUT will be connected to a resistor to GND, and R is 77Ω). If VBAT is to be charged to a high level, the trickle charge current of the charger should be greater than 15.6mA (1.2V / 77Ω), otherwise VBAT cannot be pulled high, EN cannot be normally pulled high, and the active battery switch cannot be turned on. However, because the battery safety regulation requires that the trickle charge current is less than or equal to 0.025C (0.025C is the charging rate, and C is the battery capacity), for batteries with a capacity less than or equal to 624mAh, this charger cannot be used (0.025 * 624 = 15.6). But 80% of the battery capacities of wearable products are less than 500mAh, so the current design has application limitations and cannot meet the current product requirements.

[0031] Considering the above situation, this application Figure 1 improves the charging circuit in it to ensure that the trickle charge current meets the requirement of being greater than 15.6mA.

[0032] References to "one embodiment" or "some embodiments" etc. described in the specification of the present application mean that a specific feature, structure, or characteristic described in connection with that embodiment is included in one or more embodiments of the present application. Thus, statements such as "in one embodiment", "in some embodiments", "in other some embodiments", "in still other embodiments", etc. that appear in different places in this specification do not necessarily all refer to the same embodiment, but mean "one or more but not all embodiments", unless otherwise specifically emphasized in other ways. The terms "comprising", "including", "having" and their variants all mean "including but not limited to", unless otherwise specifically emphasized in other ways.

[0033] As Figure 2 shown in the present application provides a charging circuit, which includes a charger, a first control switch, a second control switch, a BTB connector, an activation battery switch, and a battery.

[0034] Among them, the charger includes: a VBAT pin and a VSYS pin; the VBAT pin is sequentially connected to the first control switch, the first port of the BTB connector, and the first input end of the activation battery switch; the VSYS pin is sequentially connected to the second control switch, the first port of the BTB connector, and the first input end of the activation battery switch; the output end of the activation battery switch is connected to the battery.

[0035] It should be noted that both the first control switch and the second control switch are switches that conduct unidirectionally and cut off in the reverse direction. In this way, the situation of mutual leakage between VBAT and VSYS can be prevented. Optionally, the first control switch is a diode; the positive electrode of the first control switch is connected to the VBAT pin, and the negative electrode of the first control switch is connected to the first port of the BTB connector. By introducing the first control switch as a diode, the leakage of VSYS to VBAT can be prevented. The second control switch is a diode; the positive electrode of the second control switch is connected to the VSYS pin, and the negative electrode of the second control switch is connected to the first port of the BTB connector. By introducing the second control switch as a diode, the leakage of VBAT to VSYS can be prevented, and the influence on VBAT after VSYS loses power can be prevented. Optionally, the second port of the BTB connector is respectively connected to the VBAT pin and the second input end of the activation battery switch. The first output end of the activation battery switch is connected to the positive electrode of the battery, and the second output end of the activation battery switch is connected to the negative electrode of the battery. The activation battery switch includes a first resistor, and the first resistor is used to release the voltage at the second output end of the activation battery switch. As Figure 3 described, it is a schematic structural diagram of another charging circuit provided by the embodiment of the present application. Relative to Figure 1 , this Figure 3A first control switch D1 and a second control switch D2 are additionally added, where the positive electrode of D2 is connected to VSYS, the negative electrode is connected to a 100KΩ resistor, the positive electrode of D1 is connected to VBAT, and the negative electrode of D1 is connected to the 100KΩ resistor.

[0036] When VBUS is inserted, D2 conducts, activating the battery switch to conduct and using VSYS to pull up EN. The output current of VSYS is greater than 500mA, activating the battery switch to conduct normally, and VBAT = VOUT = VIN = VBAT+. After the battery switch is activated to conduct, even if VBUS is unplugged, VBAT pulls up EN through D1. At this time, VBAT is equal to the battery voltage, and the output current capacity of the battery can fully meet the requirement of being greater than 15.6mA.

[0037] Figure 3 With the help of D1, leakage from VSYS to VBAT can be prevented; with the help of D2, power-down of VSYS (entering ship mode (where ship mode is the transportation and storage mode, which mainly reduces the power consumption of electronic products during transportation or storage and ensures that the product has power and can be normally powered on when it reaches the user's hands), VSYS will drop to 0V; hard reset by pressing the button, VSYS will drop to 0V) interfering with VBAT can be prevented; leakage from VBAT to VSYS can also be prevented; in addition, if VBAT loses power, then EN loses power, and the loss of power of EN will cause the system to shut down abnormally.

[0038] Normally, EN needs to pull a separate wire from the VBAT network to prevent second-time charged connection. If EN is pulled from VBAT_CON, then after the BTB is disconnected, EN = VBAT_CON = VIN = VBAT+, so EN will always be high and the switch will always conduct, resulting in the risk of charged connection when the BTB is connected for the second time.

[0039] In this application, after the charger is connected to the power supply voltage, it can provide the voltage required to activate the battery switch through VSYS. By providing the voltage required to activate the battery switch through VSYS, a small trickle charge current of VBAT can be ensured, while meeting the design of raising VBAT and having a small trickle charge current of VBAT. Raising VBAT ensures the conduction of the battery switch, and the small trickle charge current of VBAT can also ensure compliance with battery safety regulations.

[0040] Figure 4 A charging method provided by this application is shown, and this method can be applied to the charging circuit in the above Figure 2 or Figure 4 and execute as follows:

[0041] Step 401, receive the power supply voltage.

[0042] Step 402: Provide the voltage required for activating the first input terminal of the battery switch through the VSYS pin of the charger and the second control switch.

[0043] When the power supply is disconnected, the VBAT pin of the charger, the first control switch, the first port of the BTB connector, the first input terminal of the activation battery switch, the second input terminal of the activation battery switch, and the second port of the BTB connector form a closed loop, which can ensure that the activation battery switch is in the conducting state and the current is greater than 15.6 mA.

[0044] The embodiment of the present application also provides a charging system, including a plurality of loads and the above-mentioned charging circuit. For the description of the charging circuit, the embodiment of the present application will not elaborate herein.

[0045] Those skilled in the art should understand that the embodiments of the present application can be provided as methods, systems, or computer program products. Therefore, the present application can adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware aspects. Moreover, the present application can adopt the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0046] The present application is described with reference to the flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to the present application. It should be understood that each process and / or block in the flowchart and / or block diagram can be implemented by computer program instructions, and the combination of processes and / or blocks in the flowchart and / or block diagram can also be implemented by computer program instructions. These computer program instructions can be provided to the processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing devices to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing devices generate a device for implementing the functions specified in Figure 1 one process or multiple processes and / or blocks Figure 1 one block or multiple blocks.

[0047] These computer program instructions can also be stored in a computer-readable memory that can direct a computer or other programmable data processing device to work in a specific manner, so that the instructions stored in the computer-readable memory generate a manufactured product including an instruction device, and the instruction device implements the functions specified in Figure 1 one process or multiple processes and / or blocks Figure 1 one block or multiple blocks.

[0048] These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus, so that a series of operation steps are performed on the computer or other programmable apparatus to produce a computer-implemented process, thereby providing instructions for implementing the steps of the process Figure 1 in one process or a plurality of processes and / or blocks Figure 1 or steps of functions specified in one block or a plurality of blocks.

[0049] Obviously, those skilled in the art can make various changes and modifications to this application without departing from the scope of protection of this application. Thus, if these modifications and variations of this application fall within the scope of the claims of this application and their equivalent technologies, this application is also intended to include these modifications and variations.

Claims

1. A charging circuit, characterized in that, Comprising: A charger, a first control switch, a second control switch, a BTB connector, an activation battery switch, and a battery; The charger comprises: a VBAT pin and a VSYS pin; The VBAT pin is sequentially connected to the first control switch, the first port of the BTB connector, and the first input end of the activation battery switch; the VSYS pin is sequentially connected to the second control switch, the first port of the BTB connector, and the first input end of the activation battery switch; the output end of the activation battery switch is connected to the battery, and the first input end of the activation battery switch is the EN end.

2. The charging circuit according to claim 1, wherein The first control switch is a diode; The positive electrode of the first control switch is connected to the VBAT pin, and the negative electrode of the first control switch is connected to the first port of the BTB connector.

3. The charging circuit according to claim 1 or 2, wherein The second control switch is a diode; The positive electrode of the second control switch is connected to the VSYS pin, and the negative electrode of the second control switch is connected to the first port of the BTB connector.

4. The charging circuit according to claim 3, wherein The second port of the BTB connector is respectively connected to the VBAT pin and the second input end of the activation battery switch.

5. The charging circuit according to claim 1, wherein The first output end of the activation battery switch is connected to the positive electrode of the battery, and the second output end of the activation battery switch is connected to the negative electrode of the battery.

6. The charging circuit according to claim 1, wherein The activation battery switch includes a first resistor, and the first resistor is used to release the voltage at the second output end of the activation battery switch.

7. A charging method, characterized in that, Applied to the charging circuit according to any one of claims 1-6, the method comprises: Receiving a power supply voltage; Providing the voltage required for the first input end of the activation battery switch through the VSYS pin of the charger and the second control switch.

8. The method according to claim 7, wherein After the power supply is disconnected, a closed loop is formed by the VBAT pin of the charger, the first control switch, the first port of the BTB connector, the first input end of the activation battery switch, the second input end of the activation battery switch, and the second port of the BTB connector.

9. The method according to claim 8, wherein Both the first control switch and the second control switch are diodes.

10. A charging system, characterized in that, Comprising the charging circuit according to any one of claims 1-6 and a load circuit.

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