Charging protection circuit and electronic device

Abstract

A charging protection circuit comprises a first interface for connecting an external power supply, a charging chip including an input end, a first output end, a second output end and a control end, the input end is electrically connected to the first interface, the first output end is electrically connected to a power receiving unit, for converting the voltage provided by the external power supply into a preset voltage to power the power receiving unit, the second output end is electrically connected to a battery, for charging the battery, a protection unit is electrically connected between the battery and the second output end, and is also electrically connected to the control end, for disconnecting the connection between the battery and the second output end according to the control signal output by the control end when the voltage of the battery exceeds a preset value, thereby avoiding the backflow of the power supply to the battery after the battery is fully charged, which can easily cause the battery to swell.

Description

Technical Field

[0001] This invention relates to the field of charging, and more particularly to a charging protection circuit and electronic device. Background Technology

[0002] Rechargeable batteries need to be charged repeatedly during use. However, if the charging circuit is not disconnected in time after the battery is fully charged, it will cause overcharging and damage to the battery, such as bulging. Summary of the Invention

[0003] Therefore, it is necessary to provide a charging protection circuit to prevent the power supply from flowing back into the battery after it is fully charged, which could cause the battery to bulge.

[0004] One embodiment of the present invention provides a charging protection circuit, comprising:

[0005] The first interface is used to connect an external power source;

[0006] The charging chip includes an input terminal, a first output terminal, a second output terminal, and a control terminal. The input terminal is electrically connected to the first interface, the first output terminal is electrically connected to the power receiving unit, and is used to convert the voltage provided by the external power supply into a preset voltage to power the power receiving unit. The second output terminal is electrically connected to the battery and is used to charge the battery.

[0007] The protection unit is electrically connected between the battery and the second output terminal, and also electrically connected to the control terminal. It is used to disconnect the battery from the second output terminal according to the control signal output by the control terminal when the battery voltage exceeds a preset value.

[0008] Preferably, it further includes a detection unit electrically connected to the battery, the charging chip and the first interface, for detecting the voltage of the battery.

[0009] Preferably, the protection unit includes:

[0010] The first electronic switch includes a first terminal, a second terminal, and a control terminal. The control terminal of the first electronic switch is electrically connected to the control terminal of the charging chip through a first resistor. The first terminal of the first electronic switch is electrically connected to the battery through a second resistor. The second terminal of the first electronic switch is grounded.

[0011] The second electronic switch includes a first terminal, a second terminal, and a control terminal. The control terminal of the second electronic switch is electrically connected to the first terminal of the first electronic switch through a third resistor, and the second terminal of the second electronic switch is grounded.

[0012] The third electronic switch includes a first terminal, a second terminal, and a control terminal. The control terminal of the third electronic switch is electrically connected to the first terminal of the second point switch. The first terminal of the third electronic switch is electrically connected to the battery and is also electrically connected to the first terminal of the second electronic switch through a third resistor. The second terminal of the third electronic switch is electrically connected to the second output terminal of the charging chip.

[0013] Preferably, when the detection unit detects that the battery voltage exceeds the preset value, the control terminal of the charging chip outputs a high level, the first electronic switch is turned on, the second electronic switch is turned off, and the third electronic switch is turned off to disconnect the battery from the charging chip.

[0014] Preferably, when the detection unit detects that the battery voltage does not exceed the preset value, the control terminal of the charging chip outputs a low level, the first electronic switch is turned off, the second electronic switch is turned on, and thus the third electronic switch is turned on, thereby charging the battery through the charging chip.

[0015] Preferably, when the detection unit detects that the external power supply is unplugged from the first interface, the control terminal of the charging chip outputs a low level, causing the first electronic switch to turn off, the second electronic switch to turn on, and thus the third electronic switch to turn on.

[0016] Preferably, the protection unit further includes:

[0017] The first diode has its anode connected to the first terminal of the third electronic switch and its cathode connected to the second terminal of the third electronic switch. When the third electronic switch is turned off and the external power supply is unplugged from the first interface or the power receiving unit generates power exceeding a preset power consumption, the first diode is forward-biased and the battery supplies power to the power receiving unit.

[0018] Preferably, the electrostatic discharge protection unit is electrically connected between the battery and ground to divert electrostatic current to ground.

[0019] In view of this, it is also necessary to provide an electronic device that prevents power from flowing back into the battery after it is fully charged, which could cause the battery to bulge.

[0020] One embodiment of the present invention also provides an electronic device, including the charging protection circuit described in any of the above claims.

[0021] Compared with the prior art, the charging protection circuit provided by the embodiments of the present invention sets up a protection unit between the first interface and the external power supply, and controls the opening and closing of the protection unit by outputting a control signal according to the current voltage value of the battery through the charging chip. When the battery voltage exceeds the preset value, the protection unit is controlled to disconnect according to the control signal output by the control terminal of the charging chip, thereby disconnecting the battery from the external power supply, thereby avoiding the power supply flowing back into the battery after the battery is fully charged, which would easily cause the battery to bulge. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of a module of one embodiment of the charging protection circuit of the present invention;

[0023] Figure 2 This is a circuit diagram of another embodiment of the charging protection circuit of the present invention.

[0024] Explanation of main component symbols

[0025] Charging protection circuit 1

[0026] External power supply 2

[0027] Power receiving unit 3

[0028] Battery 4

[0029] First interface 100

[0030] Protection Unit 101

[0031] Detection unit 102

[0032] Electrostatic protection unit 103

[0033] First electronic switch - Third low electronic switch S1-S3

[0034] First capacitor - Third capacitor C1-C3

[0035] First resistor - Fourth resistor R1-R4

[0036] First diode D1

[0037] The following detailed description, in conjunction with the accompanying drawings, will further illustrate the present invention. Detailed Implementation

[0038] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs; the terminology used herein in the specification of the application is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms "comprising" and "having," and any variations thereof, in the specification, claims, and foregoing drawings of this application are intended to cover non-exclusive inclusion. The terms "first," "second," etc., in the specification, claims, or foregoing drawings of this application are used to distinguish different objects, not to describe a particular order.

[0039] In this document, the term "implementation" means that a specific feature, structure, or characteristic described in connection with an implementation may be included in at least one implementation of this application. The appearance of this phrase in various places in the specification does not necessarily refer to the same implementation, nor is it a separate or alternative implementation mutually exclusive with other implementations. It will be explicitly and implicitly understood by those skilled in the art that the implementations described herein can be combined with other implementations.

[0040] See Figure 1 As shown, Figure 1 This is a schematic diagram of a module of one embodiment of the charging protection circuit 1 of the present invention. In this embodiment, the charging protection circuit 1 includes a first interface 100, a charging chip U1, and a protection unit 101. The first interface 100 can be an interface such as USB that can obtain external power. An external power source 2 is connected through the first interface 100, and the charging chip U1 converts the external power source 2 into a preset voltage to supply power to the receiving unit 3 and to charge the battery 4. This preset voltage can be determined according to actual application requirements. The receiving unit 3 can be an electronic device, such as a module / system of a laptop, mobile phone, or other electronic product that requires power.

[0041] In this embodiment, the first interface 100 is used to connect to an external power source 2. The charging chip U1 includes an input terminal, a first output terminal, a second output terminal, and a control terminal. The input terminal is electrically connected to the first interface 100, the first output terminal is electrically connected to the receiving unit, and is used to convert the voltage provided by the external power source 2 into a preset voltage to power the receiving unit 3. The second output terminal is electrically connected to the battery 4 and is used to charge the battery 4. The protection unit 101 is electrically connected between the battery 4 and the second output terminal, and is also electrically connected to the control terminal. When the voltage of the battery 4 exceeds a preset value, such as 4.3V, it disconnects the battery 4 from the second output terminal according to the control signal output by the control terminal, that is, it cuts off the connection between the battery 4 and the external power source 2, preventing the power source from flowing back into the battery 4 after it is fully charged, which could easily cause the battery to bulge.

[0042] See Figure 2 As shown, Figure 2This is a circuit diagram illustrating one embodiment of the charging protection circuit 1 of the present invention. In this embodiment, the charging protection circuit 1 includes a first interface 100, a charging chip U1, a protection unit 101, a detection unit 102, and an electrostatic protection unit 103. The connection relationship and working principle of the first interface 100, the charging chip U1, and the protection unit 101 are similar to those in the above embodiment, and will not be repeated here.

[0043] In this embodiment, the detection unit 102 is electrically connected to the battery 4, the charging chip U1 and the first interface 100, and is used to detect the voltage of the battery 4, so that the charging chip outputs a control signal to the protection unit 101 according to the current voltage of the battery 4.

[0044] In this embodiment, the protection unit 101 includes: a first electronic switch S1, including a first terminal, a second terminal, and a control terminal; the control terminal of the first electronic switch S1 is electrically connected to the control terminal of the charging chip U1 through a first resistor R1; the first terminal of the first electronic switch S1 is electrically connected to the battery 4 through a second resistor R2; and the second terminal of the first electronic switch S1 is grounded; a second electronic switch S2, including a first terminal, a second terminal, and a control terminal; the control terminal of the second electronic switch S2 is electrically connected to the first terminal of the first electronic switch S1 through a third resistor R3; and the second terminal of the second electronic switch S2 is grounded; a third electronic switch S3, including a first terminal, a second terminal, and a control terminal; the control terminal of the third electronic switch S3 is electrically connected to the first terminal of the second electronic switch S2; the first terminal of the third electronic switch S3 is electrically connected to the battery 4 and also connected to the first terminal of the second electronic switch S2 through a third resistor R3; and the second terminal of the third electronic switch S3 is electrically connected to the second output terminal of the charging chip U1.

[0045] When the detection unit 102 detects that the voltage of battery 4 exceeds the preset value, the control terminal of charging chip U1 outputs a high level, the first electronic switch S1 is turned on, the second electronic switch S2 is turned off, and the third electronic switch S3 is turned off to disconnect the connection between battery 4 and charging chip U1, that is, to cut off the connection between battery 4 and external power supply 2, thus preventing power from flowing back into battery 4 after it is fully charged, which could easily cause the battery to bulge. When the detection unit 102 detects that the voltage of battery 4 does not exceed the preset value, the control terminal of charging chip U1 outputs a low level, the first electronic switch S1 is turned off, the second electronic switch S2 is turned on, and the third electronic switch S3 is turned on, thereby charging battery 4 through charging chip U1. When the detection unit 102 detects that external power supply 2 is unplugged from the first interface 100, the control terminal of charging chip U1 outputs a low level, causing the first electronic switch S1 to turn off, the second electronic switch S2 to turn on, and the third electronic switch S3 to turn on.

[0046] Specifically, the first electronic switch S1 can be an N-type MOSFET, the second electronic switch S2 can be an N-type MOSFET, and the third electronic switch S3 can be a P-type FET, but this is not a limitation. The first electronic switch S1, the second electronic switch S2, and the third electronic switch S3 can be set according to actual needs.

[0047] In this embodiment, the protection unit 101 further includes a first diode D1, with its anode connected to the first terminal of the third electronic switch S3 and its cathode connected to the second terminal of the third electronic switch S3. When the third electronic switch S3 is turned off and the external power supply 2 is unplugged from the first interface 100 or the power receiving unit 3 generates power exceeding the preset power consumption, the first diode D1 is forward-biased and the battery 4 supplies power to the power receiving unit 3.

[0048] In this embodiment, the charging protection circuit 1 further includes an electrostatic protection unit 103, which is electrically connected between the battery 4 and ground, and is used to divert electrostatic current to ground.

[0049] In this embodiment, the charging protection circuit 1 further includes a first capacitor C1, one end of which is electrically connected to the battery and the other end is grounded; a second capacitor C2, one end of which is electrically connected to the second output terminal of the charging chip U2 and the other end is grounded; and a third capacitor C3, which is connected in parallel with the second capacitor C2. The first capacitor C1, the second capacitor C2, and the third capacitor C3 are bypass capacitors.

[0050] Compared with the prior art, the charging protection circuit provided by the embodiments of the present invention sets up a protection unit between the first interface and the external power supply, and controls the opening and closing of the protection unit by outputting a control signal according to the current voltage value of the battery through the charging chip. When the battery voltage exceeds the preset value, the protection unit is controlled to disconnect according to the control signal output by the control terminal of the charging chip, thereby disconnecting the battery from the external power supply, thereby avoiding the power supply flowing back into the battery after the battery is fully charged, which would easily cause the battery to bulge.

[0051] Those skilled in the art should recognize that the above embodiments are merely illustrative of the present invention and are not intended to limit the present invention. Any appropriate changes and modifications made to the above embodiments within the essential spirit and scope of the present invention fall within the scope of protection claimed by the present invention.

Claims

1. A charging protection circuit, characterized in that, include: The first interface is used to connect an external power source; The charging chip includes an input terminal, a first output terminal, a second output terminal, and a control terminal. The input terminal is electrically connected to the first interface, the first output terminal is electrically connected to the power receiving unit, and is used to convert the voltage provided by the external power supply into a preset voltage to power the power receiving unit. The second output terminal is electrically connected to the battery and is used to charge the battery. A protection unit, electrically connected between the battery and the second output terminal, and also electrically connected to the control terminal, is used to disconnect the battery from the second output terminal according to a control signal output by the control terminal when the battery voltage exceeds a preset value; the protection unit includes: The first electronic switch includes a first terminal, a second terminal, and a control terminal. The control terminal of the first electronic switch is electrically connected to the control terminal of the charging chip through a first resistor. The first terminal of the first electronic switch is electrically connected to the battery through a second resistor. The second terminal of the first electronic switch is grounded. The second electronic switch includes a first terminal, a second terminal, and a control terminal. The control terminal of the second electronic switch is electrically connected to the first terminal of the first electronic switch through a third resistor, and the second terminal of the second electronic switch is grounded. The third electronic switch includes a first terminal, a second terminal, and a control terminal. The control terminal of the third electronic switch is electrically connected to the first terminal of the second electronic switch. The first terminal of the third electronic switch is electrically connected to the battery and is also electrically connected to the first terminal of the second electronic switch through a fourth resistor. The second terminal of the third electronic switch is electrically connected to the second output terminal of the charging chip. The first diode has its anode connected to the first terminal of the third electronic switch and its cathode connected to the second terminal of the third electronic switch. When the third electronic switch is turned off and the power receiving unit generates power exceeding a preset power consumption, the first diode is forward-biased, and the battery supplies power to the power receiving unit.

2. The charging protection circuit as described in claim 1, characterized in that, It also includes a detection unit electrically connected to the battery, the charging chip and the first interface, for detecting the voltage of the battery.

3. The charging protection circuit as described in claim 2, characterized in that, When the detection unit detects that the battery voltage exceeds the preset value, the control terminal of the charging chip outputs a high level, the first electronic switch is turned on, the second electronic switch is turned off, and the third electronic switch is turned off to disconnect the battery from the charging chip.

4. The charging protection circuit as described in claim 2, characterized in that, When the detection unit detects that the battery voltage does not exceed the preset value, the control terminal of the charging chip outputs a low level, the first electronic switch is turned off, the second electronic switch is turned on, and the third electronic switch is turned on, thereby charging the battery through the charging chip.

5. The charging protection circuit as described in claim 2, characterized in that, When the detection unit detects that the external power supply is unplugged from the first interface, the control terminal of the charging chip outputs a low level, causing the first electronic switch to turn off, the second electronic switch to turn on, and thus the third electronic switch to turn on.

6. The charging protection circuit as described in claim 1, characterized in that, When the third electronic switch is turned off and the external power supply is disconnected from the first interface, the first diode is forward-biased, and the battery supplies power to the power receiving unit.

7. The charging protection circuit as described in claim 1, characterized in that, Also includes: An electrostatic discharge (ESD) protection unit is electrically connected between the battery and ground to divert electrostatic current to ground.

8. An electronic device, characterized in that, Includes the charging protection circuit as described in any one of claims 1-7.

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