Charging protection circuit device, chip and electronic equipment

Abstract

The utility model provides a charging protection circuit device, a chip and electronic equipment. The charging protection circuit device comprises an overvoltage protection unit and a voltage detection unit connected with the overvoltage protection unit, the voltage detection unit is used for detecting an input end voltage and outputting a voltage sampling signal to the overvoltage protection unit; and the overvoltage protection unit is used for detecting whether the voltage of the input end exceeds a preset safety threshold value or not according to the received voltage sampling signal, and outputting a corresponding control signal to the battery unit. By detecting the voltage of the input end and utilizing the overvoltage protection circuit, the charging of the lithium battery is cut off by disconnecting the MOS tube when the voltage is too high, so that the effect of protecting the lithium battery is achieved.

Description

Technical Field

[0001] This application relates to the field of integrated circuit technology, and in particular, to a charging protection circuit device, a chip, and an electronic device. Background Art

[0002] In recent years, with the development of technology and the wide application of Internet technology, TWS earphones have developed rapidly. Earphones are equipped with lithium batteries, and lithium battery charging protection has received increasing attention, and the safety test standards have become more and more strict. The 3rd edition of IEC62368 mandatorily requires that when an audio product is abnormally charged, the charging current cannot exceed the maximum charging current required in the specification. Currently, in laboratory tests, when short-circuiting the input and output of the charging IC, it is equivalent to directly applying a 5V input voltage to both ends of the battery. At this time, due to factors such as the internal resistance of the battery and the line impedance, the voltage at the cell end does not reach the lithium battery IC protection threshold, and the charging current will exceed the battery specification.

[0003] Currently, there are mainly two methods in the existing technology. One is that the chip comes with authentication, and testing can be avoided. However, for chips without authentication, it cannot be avoided. The other is to add a PTC (thermistor) in the battery path. Since the protection current of the PTC is twice the working current, it is not applicable to the scheme where the charging current exceeds 0.5 times the maximum current of the battery.

[0004] The foregoing description is for providing general background information and does not necessarily constitute prior art. Summary of the Utility Model

[0005] In view of this, this application provides a charging protection circuit device, a chip, and an electronic device to solve the problem that the charging current exceeds the maximum charging current of the battery due to the high input voltage during lithium battery charging, so as to better protect the lithium battery and maximize the charging safety.

[0006] This application provides an overvoltage protection unit and a voltage detection unit connected to the overvoltage protection unit;

[0007] The voltage detection unit is used to detect the input terminal voltage and output a voltage sampling signal to the overvoltage protection unit;

[0008] The overvoltage protection unit is used to detect whether the input terminal voltage exceeds a preset safety threshold according to the received voltage sampling signal and output a corresponding control signal to the battery unit.

[0009] Further, in some embodiments of the present application, the overvoltage protection unit includes an overvoltage comparator and an overvoltage protection circuit. The input end of the voltage comparator is connected to the output end of the voltage detection unit, the output end of the voltage comparator is connected to the input end of the overvoltage protection circuit, and the output end of the overvoltage protection circuit is connected to the input end of the battery unit;

[0010] The voltage comparator is configured to compare the received voltage sampling signal with the preset safety threshold and output a corresponding voltage comparison signal to the overvoltage protection circuit;

[0011] The overvoltage protection circuit is configured to output a corresponding control signal to the battery unit according to the received voltage comparison signal.

[0012] Further, in some embodiments of the present application, the overvoltage protection unit includes a first resistor, a second resistor, a third resistor, a diode, a triode, and a MOS transistor; one end of the first resistor is connected to the input terminal voltage, and one end of the first resistor is also respectively connected to the emitter of the triode and the source of the MOS transistor. The other end of the first resistor is respectively connected to the negative electrode of the diode and one end of the second resistor. The other end of the second resistor is connected to the base of the triode. The positive electrode of the diode is connected to one end of the third resistor and grounded. The other end of the third resistor is respectively connected to the collector of the triode and the gate of the MOS transistor. The collector of the triode is connected to the gate of the MOS transistor, and the drain of the MOS transistor is connected to the charging path.

[0013] Further, in some embodiments of the present application, a charging unit and a battery unit are further included. The input end of the charging unit is connected to a power supply, the output end of the charging unit is connected to the voltage detection unit and the overvoltage protection unit, and the input end of the battery unit is connected to the overvoltage protection unit.

[0014] Further, in some embodiments of the present application, the charging unit includes a charging socket and a charging chip. One end of the charging socket is connected to a power supply, the other end of the charging socket is connected to one end of the charging chip, and the other end of the charging chip is connected to the voltage detection unit and the overvoltage protection unit.

[0015] Further, in some embodiments of the present application, the preset safety threshold is positively correlated with the battery specifications in the battery unit.

[0016] The present application also provides a chip, including the charging protection circuit device as described above.

[0017] The present application also provides an electronic device, including the charging protection circuit device as described above or the chip as described above.

[0018] Implementing the embodiments of the present application has the following beneficial effects:

[0019] As described above, the charging protection circuit device, chip and electronic device provided by the present application, the charging protection circuit device includes an overvoltage protection unit and a voltage detection unit connected to the overvoltage protection unit; the voltage detection unit is used to detect the input terminal voltage and output a voltage sampling signal to the overvoltage protection unit; the overvoltage protection unit is used to detect whether the input terminal voltage exceeds a preset safety threshold according to the received voltage sampling signal and output a corresponding control signal to the battery unit. The present application detects the voltage at the input terminal through the voltage detection unit, and uses the overvoltage protection unit to cut off the lithium battery charging by disconnecting the MOS transistor when the voltage is too high, avoiding the problem that the charging current exceeds the maximum charging current of the battery when the input terminal voltage of the lithium battery charging is too high, thereby achieving the effect of protecting the lithium battery and maximizing the charging safety. Description of the Drawings

[0020] The drawings here are incorporated into the specification and form a part of this specification, showing the embodiments consistent with the present application, and are used together with the specification to explain the principles of the present application. 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, for those of ordinary skill in the art, other drawings can also be obtained based on these drawings without creative efforts.

[0021] Figure 1 is a schematic structural diagram of the charging protection circuit device provided by the embodiment of the present application;

[0022] Figure 2 is a specific circuit schematic diagram of the overvoltage protection unit provided by the embodiment of the present application;

[0023] Figure 3 is a specific circuit schematic diagram of the charging protection circuit device provided by the embodiment of the present application;

[0024] Figure 4 is another schematic structural diagram of the charging protection circuit device provided by the embodiment of the present application.

[0025] The realization of the purpose of the present application, functional features and advantages will be further described in conjunction with the embodiments with reference to the drawings. Through the above drawings, the clear embodiments of the present application have been shown, and there will be more detailed descriptions later. These drawings and text descriptions are not intended to limit the scope of the concept of the present application in any way, but to explain the concept of the present application to those skilled in the art by referring to specific embodiments. Detailed Embodiments

[0026] As described in the background art, there is a problem in existing lithium battery charging that the input voltage is too high at the input end, resulting in the charging current exceeding the maximum charging current of the battery.

[0027] To overcome the above technical problems, the inventor proposes a new solution. By detecting the voltage at the input end and using an overvoltage protection circuit, when the voltage is too high, the lithium battery charging is cut off to avoid the problem that the charging current exceeds the maximum charging current of the battery.

[0028] The following will clearly and completely describe the technical solutions in the embodiments of the present application with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative efforts belong to the scope of protection of the present application. Without conflict, the following various embodiments and their technical features can be combined with each other.

[0029] Please refer to Figure 1 , Figure 1 which is a schematic structural diagram of a charging protection circuit device provided by an embodiment of the present application.

[0030] In this embodiment, a charging protection circuit device is provided, which specifically may include an overvoltage protection unit 10 and a voltage detection unit 20 connected to the overvoltage protection unit 10;

[0031] The voltage detection unit 20 is configured to detect the input voltage and output a voltage sampling signal to the overvoltage protection unit 10;

[0032] The overvoltage protection unit 10 is configured to detect whether the input voltage exceeds a preset safety threshold according to the received voltage sampling signal and output a corresponding control signal to the battery unit.

[0033] Further, in some embodiments, the overvoltage protection unit includes an overvoltage comparator and an overvoltage protection circuit. The input end of the voltage comparator is connected to the output end of the voltage detection unit, the output end of the voltage comparator is connected to the input end of the overvoltage protection circuit, and the output end of the overvoltage protection circuit is connected to the input end of the battery unit;

[0034] The voltage comparator is configured to compare the received voltage sampling signal with the preset safety threshold and output a corresponding voltage comparison signal to the overvoltage protection circuit;

[0035] The overvoltage protection circuit is configured to output a corresponding control signal to the battery unit according to the received voltage comparison signal.

[0036] Specifically, a voltage comparator is used to compare the magnitudes of two voltages and output a signal based on the comparison result. In the lithium battery charging protection method, the voltage comparator is used to monitor the voltage at the charging input terminal and compare it with a preset safe voltage threshold. If the safe voltage threshold of a lithium battery charging protection circuit is set to 5.5V. The non-inverting input terminal of the voltage comparator is connected to the charging input terminal, and the inverting input terminal is connected to a stable 5.5V reference voltage source. When the input voltage is normal (e.g., 5V), the voltage comparator outputs a high-level signal, indicating that the battery can be charged normally. However, if the input voltage abnormally rises to 6V, the voltage comparator detects that the input voltage exceeds the 5.5V safe threshold and outputs a low-level signal, triggering the overvoltage protection mechanism. The MOS transistor turns off, and the charging path is cut off, thereby protecting the battery. The voltage comparator plays a key role in the lithium battery charging protection system, ensuring that the battery is charged within a safe voltage range and preventing potential safety problems such as overcharging and overheating.

[0037] Further, as Figure 2 shown, in some embodiments, the overvoltage protection unit includes a first resistor R1, a second resistor R2, a third resistor R3, a diode D1, a triode Q1, and a MOS transistor Q2; one end of the first resistor R1 is connected to the input terminal voltage, and one end of the first resistor R1 is also respectively connected to the emitter of the triode Q1 and the source of the MOS transistor Q2. The other end of the first resistor R1 is respectively connected to the negative electrode of the diode D1 and one end of the second resistor R2. The other end of the second resistor R2 is connected to the base of the triode Q1. The positive electrode of the diode D1 is connected to one end of the third resistor R3 and grounded. The other end of the third resistor R3 is respectively connected to the collector of the triode Q1 and the gate of the MOS transistor Q2. The collector of the triode Q1 is connected to the gate of the MOS transistor Q2, and the drain of the MOS transistor Q2 is connected to the charging path.

[0038] Specifically, a MOS transistor is a voltage-controlled semiconductor device. It turns on or off the conductive channel between the drain and the source by controlling the voltage on the gate. When the gate voltage reaches a certain threshold, the MOS transistor conducts, allowing current to flow; when the gate voltage is lower than the threshold, the MOS transistor turns off, blocking the current.

[0039] As Figure 3 shown, when the user is charging and an abnormality occurs, points AB are short-circuited, resulting in a relatively high voltage at point B. D1 conducts when it is higher than the trigger threshold, and Q1 also conducts, while Q2 turns off. Thus, the charging path is turned off, avoiding a relatively large charging current and protecting the lithium battery. The specific technical principle of the overvoltage protection unit is as follows:

[0040] When charging normally, the voltage at point B is normal, and the voltage at point D does not exceed the triggering threshold of D1 (preset safety threshold), so D1 is not conducting. Point F is at a high level, Q1 is not conducting, point E is at a low level, and Q2 is conducting. The battery is charging normally.

[0041] When AB is short-circuited and charging is abnormal, the voltage at point B is too high, the voltage at point D exceeds the triggering threshold of D1, and D1 conducts. Point F is at a low level, Q1 conducts, point E is at a high level, and Q2 turns off. Thereby, the battery is disconnected and not charged.

[0042] Furthermore, in some embodiments, the preset safety threshold is positively correlated with the battery specifications in the battery unit.

[0043] It should be noted that when using batteries with different voltage specifications, the specifications of D1 can be changed for adaptation. D1 with different thresholds is used to set different overvoltage protection thresholds.

[0044] Furthermore, as Figure 4 shown, in some embodiments, the charging protection circuit device further includes a charging unit 30 and a battery unit 40. The input end of the charging unit 30 is connected to a power source, the output end of the charging unit 30 is connected to the voltage detection unit 20 and the overvoltage protection unit 10, and the input end of the battery unit 40 is connected to the overvoltage protection unit 10.

[0045] Furthermore, in some embodiments of the present application, the charging unit includes a charging socket and a charging chip. One end of the charging socket is connected to a power source, the other end of the charging socket is connected to one end of the charging chip, and the other end of the charging chip is connected to the voltage detection unit and the overvoltage protection unit.

[0046] As Figure 3 shown, the charging socket can be a TypeC socket, and the battery unit can be a lithium battery.

[0047] In summary, a charging protection circuit device provided in this embodiment includes an overvoltage protection unit and a voltage detection unit connected to the overvoltage protection unit; the voltage detection unit is configured to detect the input voltage and output a voltage sampling signal to the overvoltage protection unit; the overvoltage protection unit is configured to detect whether the input voltage exceeds a preset safety threshold according to the received voltage sampling signal and output a corresponding control signal to the battery unit. In this application, the voltage detection unit detects the voltage at the input end, and the overvoltage protection unit is used to cut off the lithium battery charging by turning off the MOS transistor when the voltage is too high, avoiding the problem that the charging current exceeds the maximum charging current of the battery when the input voltage of the lithium battery charging is too high, thereby achieving the effect of protecting the lithium battery and maximizing the charging safety.

[0048] In other embodiments, a chip is further provided, which includes the charging protection circuit device as described above.

[0049] In other embodiments, an electronic device is further provided, which includes the charging protection circuit device or the chip as described above.

[0050] That is, the above descriptions are only embodiments of the present application, and do not limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made by using the content of the specification and drawings of the present application, such as the mutual combination of technical features in each embodiment, or directly or indirectly applied in other related technical fields, are similarly included in the patent protection scope of the present application.

[0051] In addition, for structural elements with the same or similar characteristics, the present application may use the same or different reference numerals for identification. In addition, the terms "first" and "second" are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more features. In the description of the present application, the meaning of "a plurality" is two or more, unless otherwise specifically defined.

[0052] In the present application, the term "for example" is used to mean "serving as an example, illustration, or explanation". Any embodiment described as "for example" in the present application is not necessarily construed as being more preferred or more advantageous than other embodiments. The above description is given to enable any person skilled in the art to implement and use the present application. In the above description, various details are set forth for purposes of explanation.

[0053] It should be understood that those of ordinary skill in the art can recognize that the present application can be implemented without using these specific details. In other embodiments, well-known structures and processes will not be elaborated in detail to avoid obscuring the description of the present application with unnecessary details. Therefore, the present application is not intended to be limited to the embodiments shown, but is consistent with the broadest scope that conforms to the principles and features disclosed in the present application.

Claims

1. A charging protection circuit device, characterized in that: It includes an overvoltage protection unit and a voltage detection unit connected to the overvoltage protection unit; The voltage detection unit is used to detect the input terminal voltage and output a voltage sampling signal to the overvoltage protection unit; The overvoltage protection unit is used to detect whether the input terminal voltage exceeds a preset safety threshold according to the received voltage sampling signal, and output a corresponding control signal to the battery unit; Wherein, the overvoltage protection unit includes a first resistor, a second resistor, a third resistor, a diode, a triode and a MOS tube; one end of the first resistor is connected to the input terminal voltage, one end of the first resistor is also respectively connected to the emitter of the triode and the source of the MOS tube, the other end of the first resistor is respectively connected to the cathode of the diode and one end of the second resistor, the other end of the second resistor is connected to the base of the triode, the anode of the diode is connected to one end of the third resistor and is grounded, the other end of the third resistor is respectively connected to the collector of the triode and the gate of the MOS tube, the collector of the triode is connected to the gate of the MOS tube, and the drain of the MOS tube is connected to the charging path.

2. The charging protection circuit device according to claim 1, characterized in that: The overvoltage protection unit comprises an overvoltage voltage comparator and an overvoltage protection circuit, the input end of the voltage comparator is connected to the output end of the voltage detection unit, the output end of the voltage comparator is connected to the input end of the overvoltage protection circuit, and the output end of the overvoltage protection circuit is connected to the input end of the battery unit; The voltage comparator is used to compare the received voltage sampling signal with the preset safety threshold and output a corresponding voltage comparison signal to the overvoltage protection circuit; The overvoltage protection circuit is used to output a corresponding control signal to the battery unit according to the received voltage comparison signal.

3. The charging protection circuit device according to claim 1, characterized in that: It also includes a charging unit and a battery unit, wherein the input end of the charging unit is connected to a power source, the output end of the charging unit is connected to the voltage detection unit and the overvoltage protection unit, and the input end of the battery unit is connected to the overvoltage protection unit.

4. The charging protection circuit device according to claim 3, characterized in that: The charging unit includes a charging socket and a charging chip, one end of the charging socket is connected to a power source, the other end of the charging socket is connected to one end of the charging chip, and the other end of the charging chip is connected to the voltage detection unit and the overvoltage protection unit.

5. The charging protection circuit device according to claim 1, characterized in that: The preset safety threshold is positively correlated with the battery specifications in the battery unit.

6. A chip, characterized in that: It comprises a charging protection circuit device as described in any one of claims 1 to 5.

7. An electronic device, characterized in that: It comprises the charging protection circuit device as described in any one of claims 1 to 5 or the chip as described in claim 6.

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