A charging circuit and electronic device

Abstract

The application discloses a charging circuit and electronic equipment. The charging circuit comprises a first charging circuit, an input end of the first charging circuit being connected with an adapter, and an output end of the first charging circuit being connected with a battery; a second charging circuit, one end of the second charging circuit being connected with the first charging circuit or the adapter, and the other end of the second charging circuit being connected with the battery; a control module, being connected with the second charging circuit; wherein, in the case that the battery is in an over-discharged state or the voltage of the battery is less than a first threshold value, the control module controls the second charging circuit to output voltage to the battery; and in the case that the battery is in an activated state, the control module controls the second charging circuit to stop outputting voltage to the battery.

Description

Technical Field

[0001] This application relates to the field of communication technology, and in particular to a charging circuit and electronic device. Background Technology

[0002] Most mobile device batteries on the market operate within a voltage range of 3.4V-4.45V, and in reality, batteries still retain charge even at 3-3.4V. A key reason for setting the normal operating voltage at 3.4V is to prevent over-discharge. In current technology, over-discharge can lead to design flaws in the charging chip, causing it to fail to output the expected system supply voltage or maintain a stable supply voltage at the trickle-to-constant current point, potentially preventing battery activation. Summary of the Invention

[0003] This application aims to provide a charging circuit to solve the problem in the prior art that the battery cannot be activated after being over-discharged.

[0004] In a first aspect, embodiments of this application provide a charging circuit, including:

[0005] A first charging circuit, wherein the input terminal of the first charging circuit is connected to the adapter, and the output terminal of the first charging circuit is connected to the battery;

[0006] A second charging circuit, one end of which is connected to the first charging circuit or to the adapter; the other end of which is connected to the battery.

[0007] The control module is connected to the second charging circuit;

[0008] Specifically, when the battery is in an over-discharged state or the battery voltage is less than a first threshold, the control module controls the second charging circuit to output voltage to the battery.

[0009] When the battery is in an active state, the control module controls the second charging circuit to stop outputting voltage to the battery.

[0010] Secondly, embodiments of this application provide an electronic device, the electronic device comprising:

[0011] Battery;

[0012] The charging circuit is the charging circuit described in the first aspect above.

[0013] Thus, the above-mentioned solution of this application adds a second charging circuit to the charging circuit of the electronic device based on the first charging circuit. The second charging circuit is used to output voltage to the battery when the battery is over-discharged or the battery voltage is low, thereby activating the battery and avoiding the problem that the battery cannot be activated due to defects in the charging chip. This allows the battery to output power even when the voltage is lower than the normal operating voltage, thereby improving the battery power utilization rate.

[0014] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0015] The above and / or additional aspects and advantages of this application will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0016] Figure 1 This is a schematic diagram of the charging circuit according to an embodiment of this application;

[0017] Figure 2 This is the second schematic diagram showing the structure of the charging circuit according to an embodiment of this application.

[0018] Explanation of reference numerals in the attached drawings: 1. First charging circuit; 2. Second charging circuit; 3. Control module; 21. First transistor; 22. Second transistor; 23. Voltage regulator circuit; 24. Voltage regulator; 231. Third transistor; 232. Zener diode. Detailed Implementation

[0019] The embodiments of this application will now be described in detail. Examples of these embodiments are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0020] The terms "first" and "second" in the specification and claims of this application may explicitly or implicitly include one or more of the features. In the description of this application, unless otherwise stated, "a plurality of" means two or more.

[0021] In the description of this application, it should be understood that the terms "front", "rear", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0022] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0023] The charging circuit according to an embodiment of this application is described below.

[0024] like Figure 1 and Figure 2 As shown, the charging circuit includes:

[0025] A first charging circuit 1, the input terminal of the first charging circuit 1 is connected to the adapter, and the output terminal of the first charging circuit 1 is connected to the battery;

[0026] The second charging circuit 2 has one end connected to the first charging circuit 1 or to the adapter; the other end of the second charging circuit 2 is connected to the battery.

[0027] Control module 3 is connected to the second charging circuit 2;

[0028] Specifically, when the battery is in an over-discharged state or the battery voltage is less than a first threshold, the control module 3 controls the second charging circuit 2 to output voltage to the battery; when the battery is in an activated state, the control module 3 controls the second charging circuit 2 to stop outputting voltage to the battery.

[0029] In this embodiment, the first charging circuit 1 and the second charging circuit 2 are disposed within the electronic device. The first charging circuit 1 may be an integrated circuit chip (IC) of the electronic device. Figure 1 and Figure 2 The internal structure of the first charging circuit 1 shown is merely an example, and it can be the structure of an existing charging IC, which is not limited in this application.

[0030] The control module 3 can be a controller of an electronic device, such as a CPU. The first charging circuit 1 is used to charge the battery normally, and the second charging circuit 2 is used to trickle charge the battery to activate it when the battery is over-discharged or the battery voltage 5 is lower than a first threshold. Figure 1 and Figure 2 As shown,

[0031] Taking the first charging circuit 1 as an example where it is an integrated charging circuit chip, the input terminal (i.e., input pin) of the first charging circuit 1 can be denoted as "CHGIN", and the output terminal (i.e., output pin) of the first charging circuit 1 is... Figure 1 and Figure 2 The pins shown are connected to the battery; in the second charging circuit

[0032] When one end of circuit 2 is connected to the first charging circuit 1, the second charging circuit 2 can be connected to the bypass pin of the charging circuit integrated chip (such as...). Figure 1 Connect the BYP pins as shown.

[0033] The first charging circuit 1 can be connected to the adapter at one end and to the second charging circuit 2 at the other end, such as... Figure 1 As shown, when the battery is in an over-discharged state or the battery voltage is less than a first threshold, the control module 3 can control the second charging circuit 2 to charge the battery.

[0034] The output voltage enables the battery to be charged at a low power to the minimum system voltage (Vsys_MIN), thereby activating the battery. When the battery reaches an activatable state or the system is operable (e.g., when the minimum system voltage is reached), the control module 3 can control the second charging circuit 2 to stop outputting voltage to the battery, and the electronic device can use the first charging circuit 1 to charge the battery normally.

[0035] The second charging circuit 2 can also be disposed between the adapter and the first charging circuit 1, such as... Figure 2 As shown, the adapter is connected to both the second charging circuit 2 and the first charging circuit 1. When the battery is over-discharged or its voltage is below a first threshold, the control module 3 can control the second charging circuit 2 to output voltage to the battery, thus charging the battery at a low power to the minimum system voltage and activating the battery. When the battery reaches an activatable state or the system is operable, the control module 3 can control the second charging circuit 2 to output voltage to the battery.

[0036] When circuit 2 stops outputting voltage to the battery, the electronic device uses the first charging circuit 1 to charge the battery normally.

[0037] For example, the voltage threshold for the over-discharge state of the battery can be set to 3.4V (or other values, such as 3V or 2.5V), and the first threshold can be 3.4V (or other lower thresholds, such as 3V or 2.5V).

[0038] The minimum system voltage can be the same as or different from the voltage threshold for the battery over-discharge state (or the first threshold). For example, the voltage threshold for the battery over-discharge state can be set to 2.5V, and the minimum system voltage can be set to 3.4V. By setting the minimum system voltage, more battery power can be effectively utilized. For example, by setting Vsys_MIN to a lower value, power can still be output even when the battery is at a lower voltage after activation. Furthermore, compared to increasing the minimum system voltage in software, this application, by setting the second charging circuit, eliminates the need to extend the pre-charging time, thus ensuring a better user experience.

[0039] In embodiments of this application, a second charging circuit is added to the charging circuit of an electronic device based on the first charging circuit. This second charging circuit is used to output voltage to the battery when the battery is over-discharged or the battery voltage is low, thereby activating the battery and enabling it to output power even when the voltage is lower than the normal operating voltage, thus improving the battery's power utilization rate. For example, the normal operating voltage of a battery is 3.4V. In the prior art, the battery cannot work normally if the voltage is lower than 3.4V. In this application, when the battery is over-discharged or the battery voltage is lower than a first threshold, the second charging circuit trickles-charges the battery, enabling the battery to be activated normally and avoiding the problem of the battery not being activated due to defects in the charging chip.

[0040] As an optional embodiment, the second charging circuit 2 includes:

[0041] The first transistor 21 has its source connected to the first charging circuit 1 and its drain connected to the battery.

[0042] The second transistor 22 has its source connected to the gate of the first transistor 21, its drain connected to ground, and its gate connected to the control module 3 through a first resistor R1.

[0043] In this embodiment, the first transistor 21 and the second transistor 22 can be field-effect transistors (MOSFETs), or simply MOS transistors. For example, Figure 1As shown, the first transistor 21 can be a PMOS transistor (P-channel MOS transistor), and the second transistor 22 can be an NMOS transistor (N-channel MOS transistor). The first transistor 21 and the second transistor 22 are connected, and the second transistor 22 is connected to the control module 3. Therefore, the control module 3 can indirectly control the first transistor 21 to be turned on or off by controlling the second transistor 22 to be turned on or off.

[0044] Optionally, the second charging circuit 2 further includes: a second resistor R2, a third resistor R3, and a fourth resistor R4; wherein, the first end of the second resistor R2 is connected to the first charging circuit 1, the second end of the second resistor R2 is connected to the first end of the third resistor R3; the second end of the third resistor R3 is connected to the drain of the second transistor 22; the first end of the fourth resistor R4 is connected to the second end of the second resistor R2, and the second end of the fourth resistor R4 is connected to the source of the second transistor 22;

[0045] The first end of the first resistor R1 is connected to the control module 3, the second end of the first resistor R1 is connected to the first end of the third resistor R3, and the first connection point of the first resistor R1 and the third resistor R3 is connected to the gate of the second transistor 22.

[0046] Optionally, when the battery is in an over-discharged state or the battery voltage is less than a first threshold, both the first transistor 21 and the second transistor 22 are in a conducting state; when the battery is in an activated state, both the first transistor 21 and the second transistor 22 are in a turned-off state.

[0047] In this embodiment, the second resistor R2 and the third resistor R3 serve as voltage divider resistors, such as... Figure 1 The working principle of the charging circuit shown is as follows:

[0048] When the adapter is connected to the electronic device, i.e., when the adapter is connected to the first charging circuit 1, it is expected to charge the battery. If the battery is in an over-discharged state or the battery voltage is less than a first threshold, the battery needs to be pre-charged and activated. QCHGIN in the first charging circuit 1 is turned on by the body diode, and the output voltage is sent to the first transistor 21. R2 and R3 form a voltage divider circuit to divide the voltage. Since the second transistor 22 is an NMOS transistor, it is turned on when the gate is at a high level. The control module 3 applies a positive voltage to the gate of the second transistor 22. When the gate voltage of the second transistor 22 is greater than Vgs (Vgs is the driving voltage, the voltage of the gate relative to the source), the second transistor 22 is turned on. The source of the second transistor 22 is connected to the gate of the first transistor 21. When the second transistor 22 is turned on, the gate voltage of the first transistor 21 decreases. Since the first transistor 21 is a PMOS transistor, it conducts when its gate is at a low level. Therefore, the PMOS transistor conduction condition is met. When the first transistor 21 is turned on, it can charge the battery at a low power, allowing the battery voltage to reach the system voltage minimum value Vsys_MIN, thus activating the battery. This embodiment can utilize trace impedance or MOS transistor voltage difference to keep the charging voltage around the battery voltage, similar to a charging bypass mode.

[0049] In this embodiment, in the event of battery over-discharge, the control module 3 controls the port of the second transistor 22 to be in a high-impedance state. When the battery reaches an activatable state or a system operable state (i.e., the voltage reaches Vsys_MIN), the battery is activated, and the control module 3 makes the gate voltage of the second transistor 22 less than Vgs, i.e., controls the second transistor 22 to turn off. The shutdown of the second transistor 22 causes the gate voltage of the first transistor 21 to go high, i.e., turns off the first transistor 21. At this time, the second charging circuit 2 does not work, and the battery cell is activated, so the system can be charged normally using the device's built-in charging IC (i.e., the first charging circuit).

[0050] In this embodiment, by setting the second charging circuit, the battery is trickle-charged and activated when it is over-discharged or has a low voltage. The output voltage is stable and cyclic. The battery cell is activated when the voltage reaches Vsys_MIN. Optionally, Vsys_MIN is greater than the over-discharge release voltage threshold of the secondary protection IC of the protection board + the voltage drop of the secondary protection discharge MOS body diode + the voltage drop of the primary protection discharge MOS in the slightly on state.

[0051] The Vsys_MIN can be set to a lower value, which can effectively utilize more battery power. Furthermore, by setting the second charging circuit, the problem of excessively long pre-charge time caused by software boosting of the Vsys_MIN voltage can be avoided.

[0052] As another optional embodiment, such as Figure 2 As shown, the second charging circuit 2 includes:

[0053] The voltage regulator circuit 23 is connected to the adapter.

[0054] A voltage regulator 24 is provided, with its input terminal connected to the voltage regulation circuit 23 and its enable terminal connected to the control module 3 via a fifth resistor R5. The output terminal of the voltage regulator 24 is connected to the battery.

[0055] In this embodiment, the voltage regulator 24 can be a low dropout linear regulator (LDO). The voltage regulator circuit 23 is connected to the adapter, and the voltage regulator circuit 23 is connected in series with the voltage regulator 24. The voltage regulator 24 is mainly responsible for outputting the battery activation waveform, and the voltage regulator circuit 23 is mainly used to control the input voltage of the voltage regulator 24. When the battery is over-discharged or the voltage is less than a first threshold, the control module 3 controls the voltage regulator 24 to turn on, providing an input voltage to the battery and activating it. After the battery is activated, the control module 3 controls the voltage regulator 24 to turn off, stopping the input voltage to the battery, and then the adapter supplies power to the battery normally through the first charging circuit 1.

[0056] The input terminal of the voltage regulator 24 can be... Figure 2 The IN pin shown can be the enable pin of the regulator 24. Figure 2 The EN pin shown can be the output of the regulator 24. Figure 2 The OUT pin is shown.

[0057] Optionally, the voltage regulator circuit 23 includes:

[0058] The third transistor 231, the collector of which is connected to the adapter, and the emitter of which is connected to the input terminal of the voltage regulator 24;

[0059] Zener diode 232, the first end of which is connected to the base of the third transistor 231, and the second end of which is connected to ground;

[0060] The sixth resistor R6 has its first end connected to the collector of the third transistor 231 and its second end connected to the base of the third transistor 271.

[0061] In this embodiment, the third transistor 231 can be a triode, such as... Figure 2As shown. The voltage regulator circuit 23 consists of the third transistor 231, the Zener diode 232, and the sixth resistor R6. The sixth resistor R6 serves as the current-limiting resistor for the Zener diode 232 and also as the bias resistor for the third transistor 231. The Zener diode 232 provides a stable base voltage to the third transistor 231. The third transistor 231 acts as an adjustment transistor, used to adjust the voltage to achieve a regulated output.

[0062] Optionally, the second charging circuit 2 further includes: a seventh resistor R7 and an eighth resistor R8;

[0063] Specifically, the first end of the seventh resistor R7 is connected to the emitter of the third transistor 231, the second end of the seventh resistor R7 is connected to the first end of the eighth resistor R8, and the second connection point of the seventh resistor R7 and the eighth resistor R8 is connected to the enable terminal of the voltage regulator 24; the second end of the eighth resistor R8 is grounded; the first end of the fifth resistor R5 is connected to the control module 3, and the second end of the fifth resistor R5 is connected to the second connection point.

[0064] The fifth resistor R5, the seventh resistor R7, and the eighth resistor R84 serve as voltage divider resistors to provide voltage for enabling the voltage regulator 24. After the battery is activated, the control module 3 can control the enable pin (ENPIN) of the voltage regulator 24 to control the on / off state of the voltage regulator 24.

[0065] Optionally, when the battery is in an over-discharged state or the battery voltage is less than a first threshold, the enable terminal of the voltage regulator 24 is at a high level (i.e., the voltage regulator 24 is turned on); when the battery is in an active state, the enable terminal of the voltage regulator 24 is at a low level (i.e., the voltage regulator 24 is turned off).

[0066] Optionally, when the adapter is connected to the first charging circuit 1, there is a first voltage difference between the base and emitter of the third transistor 231. Optionally, the first value is 0.7V.

[0067] In this embodiment, after the adapter is connected to the electronic device, the base and emitter of the third transistor 231 form a 0.7V voltage difference to supply power to the voltage regulator 24. Even if the VBUS input voltage is above 9V, the Zener diode 232 can clamp the base of the third transistor 231 to 5V, forming a 0.7V voltage difference with the emitter to supply power to the voltage regulator 24, preventing overvoltage damage to the voltage regulator 24.

[0068] When the battery is over-discharged or the voltage is low, the control module 3 controls the port of the voltage regulator 24 to be in a high-impedance state. The seventh resistor R7 and the eighth resistor R8 form a voltage divider, and the enable pin (EN) of the voltage regulator 24 is at a high level. The voltage regulator 24 outputs a cell activation voltage to the battery, charging the battery at a low power to Vsys_MIN, thus activating the battery. After the battery is activated, the control module 3 controls the enable pin of the voltage regulator 24 to be at a low level, and the voltage regulator 24 stops outputting the activation voltage. The adapter charges the battery normally through the first charging circuit 1.

[0069] This embodiment adds a simple peripheral circuit to the first charging circuit, which can output a stable cell activation waveform, effectively prevent the cell from being over-discharged and thus unable to activate, and improve the utilization rate of power.

[0070] The embodiments of this application solve the problem of battery cell activation failure due to charging chip defects by modifying the hardware circuit. Compared to increasing the Vsys_MIN voltage in software, which leads to a longer pre-charge time, this application avoids the increase in pre-charge time by setting a second charging circuit. By setting a minimum system voltage, the battery power utilization rate can be improved, enabling electronic devices to be activated normally and avoiding the problem of prolonged pre-charge time caused by software modifications, thus improving battery utilization and user experience.

[0071] Optional, such as Figure 1 and Figure 2 As shown, the system power supply pin (SYS) of the first charging circuit is connected to the load, i.e., the electrical component within the electronic device. The voltage output by this system power supply pin is:

[0072] V SYS =V BATT -(I BATT ×R BATT )

[0073] Among them, V BATT It is the battery voltage, I BATT It is the battery current, R BATT It is Q BATT The resistance value.

[0074] This application also provides an electronic device, which includes: a battery; and a charging circuit, wherein the charging circuit is the charging circuit described above.

[0075] In the embodiments of this application, a second charging circuit is added to the charging circuit of the electronic device based on the first charging circuit. The second charging circuit is used to output voltage to the battery when the battery is over-discharged or the battery voltage is low, thereby activating the battery and avoiding the problem that the battery cannot be activated due to defects in the charging chip. This allows the battery to output power even when the voltage is lower than the normal operating voltage, thereby improving the battery power utilization rate.

[0076] Other components of the electronic device according to the embodiments of this application, such as the structure and operation of the battery and casing, are known to those skilled in the art and will not be described in detail here.

[0077] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0078] Although embodiments of this application have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of this application, the scope of which is defined by the claims and their equivalents.

Claims

1. A charging circuit, characterized in that, include: A first charging circuit, wherein the input terminal of the first charging circuit is connected to the adapter, and the output terminal of the first charging circuit is connected to the battery; A second charging circuit, one end of which is connected to the first charging circuit or to the adapter; the other end of which is connected to the battery. The control module is connected to the second charging circuit; Specifically, when the battery is in an over-discharged state or the battery voltage is less than a first threshold, the control module controls the second charging circuit to output voltage to the battery. When the battery is in an activated state, the control module controls the second charging circuit to stop outputting voltage to the battery; The second charging circuit includes: The first transistor has its source connected to the first charging circuit and its drain connected to the battery. The second transistor has its source connected to the gate of the first transistor, its drain connected to ground, and its gate connected to the control module through a first resistor.

2. The charging circuit according to claim 1, characterized in that, The second charging circuit also includes: a second resistor, a third resistor, and a fourth resistor; Wherein, the first end of the second resistor is connected to the first charging circuit, the second end of the second resistor is connected to the first end of the third resistor, and the second end of the third resistor is connected to the drain of the second transistor; The first end of the fourth resistor is connected to the second end of the second resistor, and the second end of the fourth resistor is connected to the source of the second transistor. The first end of the first resistor is connected to the control module, the second end of the first resistor is connected to the first end of the third resistor, and the first connection point of the first resistor and the third resistor is connected to the gate of the second transistor.

3. The charging circuit according to claim 1, characterized in that, When the battery is in an over-discharged state or the battery voltage is less than a first threshold, both the first transistor and the second transistor are in the on state. When the battery is in an active state, both the first transistor and the second transistor are in an off state.

4. The charging circuit according to claim 1, characterized in that, The second charging circuit also includes: A voltage regulator circuit is connected to the adapter. A voltage regulator, the input terminal of which is connected to the voltage regulation circuit, and the enable terminal of which is connected to the control module through a fifth resistor; the output terminal of which is connected to the battery.

5. The charging circuit according to claim 4, characterized in that, The voltage regulator circuit includes: The third transistor, the collector of which is connected to the adapter, and the emitter of which is connected to the input terminal of the regulator; A Zener diode, wherein the first end of the Zener diode is connected to the base of the third transistor, and the second end of the Zener diode is connected to ground; A sixth resistor, the first end of which is connected to the collector of the third transistor, and the second end of which is connected to the base of the third transistor.

6. The charging circuit according to claim 5, characterized in that, The second charging circuit also includes: a seventh resistor and an eighth resistor; Wherein, the first end of the seventh resistor is connected to the emitter of the third transistor, the second end of the seventh resistor is connected to the first end of the eighth resistor, and the second connection point of the seventh resistor and the eighth resistor is connected to the enable terminal of the voltage regulator; the second end of the eighth resistor is grounded. The first end of the fifth resistor is connected to the control module, and the second end of the fifth resistor is connected to the second connection point.

7. The charging circuit according to claim 4, characterized in that, When the battery is in an over-discharged state or the battery voltage is less than a first threshold, the enable terminal of the voltage regulator is at a high level. When the battery is in an active state, the enable terminal of the voltage regulator is at a low level.

8. The charging circuit according to claim 5, characterized in that, When the adapter is connected to the first charging circuit, there is a first voltage difference between the base and emitter of the third transistor.

9. An electronic device, characterized in that, include: Battery; A charging circuit, wherein the charging circuit is the charging circuit according to any one of claims 1 to 8.

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