Power supply switching circuit and electronic device

Abstract

The present application provides a power supply switching circuit and an electronic device, the power supply switching circuit comprising: a first controlled switch connected between a second input terminal and an output terminal, a second controlled switch connected between a third controlled switch and the output terminal, and a third controlled switch connected between the second controlled switch and the first input terminal; the controlled terminals of the first controlled switch, the second controlled switch, and the third controlled switch are all connected to the second input terminal; wherein, when the second input terminal is not connected to a second power supply, the first controlled switch is turned off, and the second and third controlled switches are turned on; when the second input terminal is connected to a second power supply, the first controlled switch is turned on, and the second and third controlled switches are turned off. The power supply switching circuit can accurately control the switching of power supplies with low circuit power consumption, greatly improving the user experience and reducing energy consumption.

Description

Technical Field

[0001] The present application relates to the technical field of power supply control, and in particular to a power supply switching circuit and an electronic device. Background Art

[0002] Many electrical appliances now have built-in batteries. When there is no external power supply, they use the built-in batteries for power. When an external power supply is connected, they use the external power supply. Therefore, the circuit must be able to automatically select the corresponding power supply according to whether the external power supply is connected.

[0003] Most existing power switching circuits use diodes and MOSFETs for switching. However, due to the high power consumption of diodes, these circuits generate high heat and have low efficiency. Furthermore, they cannot function properly if the battery voltage exceeds the external voltage. Therefore, designing a power switching circuit that switches accurately while minimizing power consumption is a pressing issue. Summary of the Invention

[0004] The main purpose of this application is to provide a power supply switching circuit and an electronic device, which can better realize the switching of multiple power supplies by the power supply switching circuit, for example, to prevent the external power supply from being unable to be used normally when the voltage of the internal power supply is greater than the voltage of the external power supply.

[0005] A first aspect of the present application provides a power supply switching circuit, the power supply switching circuit including a first input terminal for connecting to a first power supply, a second input terminal for connecting to a second power supply, and an output terminal for outputting electric energy. When the power supply switching circuit is not connected to the second power supply, the first power supply outputs electric energy, and when the second power supply is connected to the second power supply, the second power supply outputs electric energy. The power supply switching circuit includes a first controlled switch, a second controlled switch, and a third controlled switch. The power supply switching circuit includes:

[0006] The first controlled switch is connected between the second input terminal and the output terminal, the second controlled switch is connected between the third controlled switch and the output terminal, and the third controlled switch is connected between the second controlled switch and the first input terminal;

[0007] The controlled end of the first controlled switch, the controlled end of the second controlled switch, and the controlled end of the third controlled switch are all connected to the second input end;

[0008] When the second input terminal is not connected to the second power supply, the first controlled switch is turned off, and the second controlled switch and the third controlled switch are turned on; when the second input terminal is connected to the second power supply, the first controlled switch is turned on, and the second controlled switch and the third controlled switch are turned off.

[0009] A second aspect of the present application further provides an electronic device, comprising:

[0010] load;

[0011] a first power source;

[0012] The power supply switching circuit is connected to the first power source and the load;

[0013] The power supply switching circuit is further configured to connect to a second power source, and when the second power source is not connected, the first power source outputs electrical energy, while when the second power source is connected, the second power source outputs electrical energy.

[0014] Compared with the prior art, the beneficial effect of the embodiments of the present application is that: by setting a power supply switching circuit between the load and the first power supply, the power supply switching circuit outputs electric energy from the first power supply when the second power supply is not connected, and outputs electric energy from the second power supply when the second power supply is connected. Through this power supply switching circuit, the switching of the power supply can be controlled accurately and with low circuit power consumption, which greatly improves the user experience and reduces energy consumption. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 A circuit diagram of an embodiment of a power supply switching circuit provided in an embodiment of the present application;

[0016] Figure 2 1 is a structural diagram of an electronic device provided in an embodiment of the present application;

[0017] Figure 3 This is another structural diagram of the electronic device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0018] Below, the present application is further described in conjunction with the accompanying drawings and specific implementation methods. It should be noted that, under the premise of no conflict, the various embodiments or technical features described below can be arbitrarily combined to form new embodiments.

[0019] Please refer to Figure 1 , Figure 1 A circuit diagram of an implementation of a power supply switching circuit provided in an embodiment of the present application.

[0020] like Figure 1 As shown, the power supply switching circuit includes a first controlled switch 101 , a second controlled switch 102 , a third controlled switch 103 , a first input terminal 201 , a second input terminal 202 and an output terminal 203 .

[0021] The first input terminal 201 is used to connect to a first power source VBAT, and the second input terminal 202 is used to connect to a second power source VIN.

[0022] Exemplarily, the first power source VBAT may be an internal power source, such as a battery; the second power source may be a power adapter capable of rectifying and transforming the mains power, and the power adapter may be located inside or outside the electronic device.

[0023] Specifically, when the second input terminal 202 is connected to the second power source VIN, the second power source VIN outputs electric energy; when the second input terminal 202 is not connected to the second power source VIN, the first power source VBAT outputs electric energy.

[0024] It can be understood that when the second power source VIN outputs power, it is determined that the second input terminal 202 is connected to the second power source VIN.

[0025] In some embodiments, the first controlled switch 101 is connected between the second input terminal 202 and the output terminal 203; the second controlled switch 102 is connected between the third controlled switch 103 and the output terminal 203; the third controlled switch is connected between the second controlled switch 102 and the first input terminal 201; and the controlled terminals of the first controlled switch 101, the second controlled switch 102, and the third controlled switch 103 are all connected to the second input terminal 202. The first controlled switch 101, the second controlled switch 102, and the third controlled switch 103 include MOS transistors Q1, Q2, and Q3, respectively.

[0026] Exemplarily, when the second input terminal 202 is connected to the second power supply VIN, the first controlled switch 101 is turned on, the second controlled switch 102 and the third controlled switch 103 are both turned off, the first power supply VBAT stops providing power, and the second power supply VIN outputs power and outputs it through the output terminal 203 to provide power to the load.

[0027] Exemplarily, when the second input terminal 202 is not connected to the second power supply VIN, the first controlled switch 101 is turned off, the second controlled switch 102 and the third controlled switch 103 are both turned on, and electric energy is output by the first power supply VBAT and output through the output terminal 203 to provide electric energy to the load.

[0028] The power supply switching circuit can accurately control the switching of power supplies with low circuit power consumption, greatly improving the user experience and reducing energy consumption.

[0029] In some embodiments, the controlled terminal of the second controlled switch 102 is grounded via a first resistor R1. When the third controlled switch 103 is turned on, a voltage difference exists between the source and gate of the MOS transistor Q2 of the second controlled switch 102, enabling the second controlled switch 102 to be turned on.

[0030] In some embodiments, the power supply switching circuit includes a first level-flipping circuit 301, through which the first controlled switch 101 is connected to the second input terminal 202. When the second input terminal 202 is connected to the second power supply VIN, the first level-flipping circuit 301 outputs a low level to the controlled terminal of the first controlled switch 101, thereby turning on the first controlled switch 101 and allowing the power provided by the second power supply VIN to flow to the output terminal 203. The first level-flipping circuit 301 outputs a low level when connected to the second power supply VIN and outputs a high level when not connected to the second power supply VIN. By outputting a low level from the first level-flipping circuit 301, the MOS transistor Q1 is turned on, thereby turning on the first controlled switch, thereby quickly connecting the second power supply VIN power supply circuit.

[0031] Specifically, the first level flipping circuit 301 includes a fourth controlled switch 104 , one end of which is connected to the controlled end of the first controlled switch 101 , and the other end is grounded. The controlled end of the fourth controlled switch 104 is connected to the second input end 202 .

[0032] In another embodiment, the controlled end of the fourth controlled switch 104 is connected to the second input end 202 via a ninth resistor R9 .

[0033] Exemplarily, when the second input terminal 202 is connected to the second power supply, the fourth controlled switch 104 is turned on, so that the first level flipping circuit 301 outputs a low level, so that the controlled terminal of the first controlled switch 101 is at a low level, one end of the first controlled switch 101 is connected to the second input terminal 202 and is at a high level, and there is a voltage difference between the gate and source of the MOS transistor Q1, so that the MOS transistor Q1 is turned on, and the power supplied by the second power supply VIN is conducted to the output terminal 203 to provide power to the load.

[0034] In some embodiments, the power supply switching circuit further includes a level-following circuit 302, through which the controlled terminal of the third controlled switch 103 is connected to the second input terminal VIN. The output of the level-following circuit 302 includes a low level or a high level. When the second input terminal 202 is not connected to the second power supply VIN, the level-following circuit 302 outputs a low level; when the second input terminal 202 is connected to the second power supply VIN, the level-following circuit 302 outputs a high level. By determining whether the output of the level-following circuit 302 is a low level or a high level, and thereby controlling the conduction or cutoff of the third controlled switch 103, the efficiency of the power supply switching circuit is improved.

[0035] Exemplarily, when the second input terminal 202 is not connected to the second power source VIN, the level follower circuit 302 outputs a low level to the controlled terminal of the third controlled switch 103, turning on the third controlled switch 103. When the third controlled switch 103 is turned on, the second controlled switch 102 is turned on, so that the power provided by the first power source connected to the first input terminal 201 flows through the third controlled switch 103 and the second controlled switch 102 to reach the output terminal 203, and is output through the output terminal 203 to provide power to the load. The output terminal 203 is accurately controlled to output the power provided by the first power source VBAT.

[0036] Exemplarily, when the second input terminal 202 is connected to the second power source VIN, the level follower circuit 302 outputs a high level to the controlled terminal of the third controlled switch 103, so that the gate voltage of the MOS transistor Q3 of the third controlled switch 103 is equal to the source voltage. The MOS transistor Q3 is turned off, that is, the third controlled switch 103 is turned off. When the third controlled switch 103 is turned off, the second controlled switch 102 is turned off, so that the power of the first power source cannot be output to the output terminal 203. The output terminal 203 is accurately controlled to output the power provided by the second power source VIN.

[0037] In some embodiments, the level follower circuit 302 includes a fifth controlled switch 105 and a second level flipping circuit 303. One end of the fifth controlled switch 105 is connected to the controlled end of the third controlled switch 103, and the other end is grounded. The controlled end of the fifth controlled switch 105 is connected to the second input end 202 via the second level flipping circuit 303. The fifth controlled switch 105 includes a transistor Q5.

[0038] In some embodiments, the controlled end of the fifth controlled switch 105 is connected to one end of the second level flipping circuit 303 via the second resistor R2 , and the controlled end of the fifth controlled switch 105 is also grounded via the fifth resistor R5 .

[0039] Exemplarily, when the second input terminal 202 is not connected to the second power supply VIN, the second level-flipping circuit 302 outputs a high level to the controlled terminal of the fifth controlled switch 105, turning on the fifth controlled switch 105 and grounding the controlled terminal of the third controlled switch 103. A voltage difference exists between the gate and source of the MOS transistor Q3 of the third controlled switch 103, turning on the third controlled switch 103. When the second input terminal 202 is not connected to the second power supply VIN, the third controlled switch 103 is accurately controlled to be turned on.

[0040] Exemplarily, when the second input terminal 202 is connected to the second power supply VIN, the second level-inverting circuit 302 outputs a low level to the controlled terminal of the fifth controlled switch 105, turning off the fifth controlled switch 105. When the fifth controlled switch 105 is turned off, the third controlled switch 103 is turned off. When the second input terminal 202 is connected to the second power supply VIN, the third controlled switch 103 is accurately controlled to be turned off.

[0041] In some embodiments, the second level-flipping circuit 302 includes a sixth controlled switch 106. One end of the sixth controlled switch 106 is connected to the first input terminal 201 and to the controlled end of the fifth controlled switch 105 via the second resistor R2. The other end of the sixth controlled switch 106 is grounded. The controlled end of the sixth controlled switch 106 is connected to the second input terminal 202. The sixth controlled switch includes a transistor Q6.

[0042] In other embodiments, the sixth controlled switch 106 is connected to the first input terminal 201 through a sixth resistor R6 , connected to the second input terminal 202 through a seventh resistor R7 , and the controlled terminal of the sixth controlled switch 106 is grounded through an eighth resistor R8 .

[0043] Exemplarily, when the second input terminal 202 is not connected to the second power supply VIN, the base and emitter voltages of the transistor Q6 of the sixth controlled switch 106 are equal, causing the transistor Q6 to be turned off. That is, the sixth controlled switch 106 is turned off, and the controlled terminal of the fifth controlled switch 105 is set to a high level, turning on. When the second input terminal 202 is not connected to the second power supply VIN, the transistor Q6 is turned off, thereby accurately controlling the fifth controlled switch 105 to be turned on.

[0044] Exemplarily, when the second input terminal 202 is connected to the second power supply VIN, a voltage difference exists between the base and emitter of the transistor Q6 of the sixth controlled switch 106, causing the transistor Q6 to turn on. That is, the sixth controlled switch 106 is turned on, and the controlled terminal of the fifth controlled switch 105 is grounded and turned off. When the second input terminal 202 is connected to the second power supply VIN, the transistor Q6 is turned on, thereby accurately controlling the fifth controlled switch 105 to turn off.

[0045] In some embodiments, the controlled end of the first controlled switch 101 is connected to the output end 203 of the power switching circuit via the third resistor R3 . When the fourth controlled switch 104 is turned on, the controlled end of the first controlled switch 101 is grounded.

[0046] In other embodiments, the controlled end of the third controlled switch 103 is connected to the first input terminal 201 via a fourth resistor R4. When the fifth controlled switch 105 is on, the controlled end of the third controlled switch 103 is grounded. When the fifth controlled switch 105 is off, the controlled end of the third controlled switch 103 is connected to the first power supply VBAT of the first input terminal 201 via the fourth resistor R4. When the fifth controlled switch 105 is on, the fourth resistor R4 prevents a short circuit in the first power supply VBAT.

[0047] In some embodiments, the first controlled switch 101 , the second controlled switch 102 , and the third controlled switch 103 are MOS transistors; the fourth controlled switch 104 , the fifth controlled switch 105 , and the sixth controlled switch 106 are triodes.

[0048] Exemplarily, the first controlled switch 101 is a MOS transistor Q1, the second controlled switch 102 is a MOS transistor Q2, the third controlled switch 103 is a MOS transistor Q3, the fourth controlled switch 104 is a transistor Q4, the fifth controlled switch 105 is a transistor Q5, and the sixth controlled switch 106 is a transistor Q6. MOS transistor Q1, MOS transistor Q2, or MOS transistor Q3 is turned on when there is a voltage difference between the gate and the source, i.e., the first controlled switch 101, the second controlled switch 102, or the third controlled switch 103 is turned on when there is a voltage difference between the gate and the source. When the base voltage of the transistor Q4, the transistor Q5, or the transistor Q6 is greater than the emitter voltage, the transistor Q4, the transistor Q5, or the transistor Q6 is turned on, i.e., the fourth controlled switch 104, the fifth controlled switch 105, or the sixth controlled switch 106 is turned on.

[0049] In some embodiments, when the second input terminal 202 is connected to the second power source VIN, the fourth controlled switch 104 is turned on. This turns on the first controlled switch 101, allowing the power provided by the second power source to flow out of the output terminal 203. When the second input terminal 202 is connected to the second power source VIN, the sixth controlled switch 106 is turned on. This turns on the sixth controlled switch 106, causing the output to the controlled terminal of the fifth controlled switch 105 to be low, turning off the fifth controlled switch 105 and the third controlled switch 103. This turns off the third controlled switch 103, preventing the power provided by the first power source from being output to the output terminal 203. This turns off the third controlled switch 103, turning off the second controlled switch, preventing the second power source from charging the first power source. When the second input terminal 202 is connected to the second power source VIN, the power supply switching circuit can accurately switch the power supply to the second power source VIN.

[0050] In other embodiments, when the second input terminal 202 is not connected to the second power source VIN, the first controlled switch 101, the fourth controlled switch 104, and the sixth controlled switch 106 are turned off. When the sixth controlled switch 106 is turned off, the controlled terminal of the fifth controlled switch 105 is connected to a high level, turning on the fifth controlled switch 105. The turning on of the fifth controlled switch 105 grounds the controlled terminal of the third controlled switch 103, turning on the third controlled switch 103. The turning on of the third controlled switch 103 turns on the second controlled switch 102, allowing the power provided by the first power source to flow through the third controlled switch 103 and the second controlled switch 102 to the output terminal 203 for use by the load. When the second input terminal 202 is not connected to the second power source VIN, the power provided by the first power source VBAT can be accurately output for use by the load.

[0051] Please refer to the above examples Figure 2 and Figure 3 , Figure 2 is a structural diagram of an electronic device provided in an embodiment of the present application, Figure 3 This is another structural diagram of the electronic device provided in an embodiment of the present application.

[0052] like Figure 2 and Figure 3 As shown, the electronic device includes:

[0053] load 410;

[0054] a first power source 420;

[0055] The power supply switching circuit 430 is configured to be connected to the first power source 420 and the load 410 .

[0056] Specifically, the power supply switching circuit is also used to connect to the second power supply 440, and when the second power supply 440 is not connected, the first power supply 420 outputs power, and when the second power supply 440 is connected, the second power supply 440 outputs power.

[0057] Exemplarily, the electronic device includes a power interface, and the power switching circuit is connected to the power interface. When the power interface is connected to a second power source, the second power source 440 supplies power to the load 410 through the power switching circuit 430. When the power interface is not connected to the second power source, the first power source 420 supplies power to the load 410 through the power switching circuit 430.

[0058] Exemplarily, the electronic device includes at least one of a lamp, a speaker, and a fan. For example, when the electronic device is a fan, its load includes a motor.

[0059] The power supply switching circuit provided in the embodiments of this specification is configured such that a power supply switching circuit is provided between a load and a first power supply. When the power supply switching circuit is not connected to a second power supply, the first power supply outputs electrical energy, and when the second power supply is connected, the second power supply outputs electrical energy. The power supply switching circuit can accurately control the switching of power supplies with low circuit power consumption, thereby greatly improving the user experience and reducing energy consumption.

[0060] In the description of this application, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood broadly. For example, they can refer to fixed connections, detachable connections, or integral connections. They can refer to mechanical connections or electrical connections. They can refer to direct connections or indirect connections through an intermediary. They can refer to internal communication between two components or interactions between two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on the specific circumstances.

[0061] In this application, unless otherwise expressly specified or limited, a first feature being "above" or "below" a second feature may include the first and second features being in direct contact, or may include the first and second features being in contact not directly but through another feature between them. Moreover, a first feature being "above," "above," and "above" a second feature may include the first feature being directly above or obliquely above the second feature, or may simply mean that the first feature is higher in level than the second feature. A first feature being "below," "below," and "below" a second feature may include the first feature being directly below or obliquely below the second feature, or may simply mean that the first feature is lower in level than the second feature.

[0062] The disclosure above provides many different embodiments or examples for realizing the different structures of the present application. In order to simplify the disclosure of the present application, the components and settings of specific examples are described above. Of course, they are merely examples and are not intended to limit the present application. In addition, the present application may repeat reference numerals and / or reference letters in different examples, and such repetition is for the purpose of simplicity and clarity, and does not itself indicate the relationship between the various embodiments and / or settings discussed. In addition, the present application provides examples of various specific processes and materials, but those of ordinary skill in the art will appreciate the application of other processes and / or the use of other materials.

[0063] Throughout this specification, reference to terms such as "one embodiment," "some embodiments," "illustrative embodiments," "examples," "specific examples," or "some examples" means that a specific feature, structure, material, or characteristic described in conjunction with an embodiment or example is included in at least one embodiment or example of the present application. In this specification, the schematic representations 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 any one or more embodiments or examples.

[0064] The above-mentioned embodiments are only preferred embodiments of the present application and cannot be used to limit the scope of protection of the present application. Any non-substantial changes and replacements made by technicians in this field based on the present application shall fall within the scope of protection required by the present application.

Claims

1. A power supply switching circuit, characterized in that: The power supply switching circuit includes a first input terminal for connecting to a first power source, a second input terminal for connecting to a second power source, and an output terminal for outputting electric energy. When the power supply switching circuit is not connected to the second power source, the first power source outputs electric energy, and when the second power source is connected, the second power source outputs electric energy. The power supply switching circuit includes a first controlled switch, a second controlled switch, a third controlled switch and a first level flipping circuit, and the power supply switching circuit includes: The first controlled switch is connected between the second input terminal and the output terminal, the second controlled switch is connected between the third controlled switch and the output terminal, and the third controlled switch is connected between the second controlled switch and the first input terminal; The controlled end of the first controlled switch is connected to the second input end through a first level flipping circuit, and the controlled end of the second controlled switch and the controlled end of the third controlled switch are both connected to the second input end; a level follower circuit, wherein the controlled end of the third controlled switch is connected to the second input end through the level follower circuit; When the second input terminal is not connected to the second power supply, the first controlled switch is turned off, and the second controlled switch and the third controlled switch are turned on; when the second input terminal is connected to the second power supply, the first level flipping circuit outputs a low level to the controlled terminal of the first controlled switch, the first controlled switch is turned on, and the second controlled switch and the third controlled switch are turned off; When the second input terminal is not connected to the second power supply, the level follower circuit outputs a low level to the controlled terminal of the third controlled switch to turn on the third controlled switch, and when the third controlled switch is turned on, the second controlled switch is turned on; When the second input terminal is connected to a second power supply, the level follower circuit turns off the third controlled switch, and when the third controlled switch is turned off, the second controlled switch is turned off.

2. The power supply switching circuit according to claim 1, wherein: The power supply switching circuit further includes a first resistor, A controlled end of the second controlled switch is grounded through the first resistor.

3. The power supply switching circuit according to claim 2, wherein: The first level flipping circuit includes a fourth controlled switch; One end of the fourth controlled switch is connected to the controlled end of the first controlled switch, and the other end is grounded. The controlled end of the fourth controlled switch is connected to the second input end.

4. The power supply switching circuit according to claim 1, wherein: The level follower circuit includes a fifth controlled switch and a second level flipping circuit, one end of the fifth controlled switch is connected to the controlled end of the third controlled switch, and the other end is grounded, and the controlled end of the fifth controlled switch is connected to the second input end through the second level flipping circuit; When the second input terminal is not connected to the second power supply, the second level flipping circuit outputs a high level to the controlled terminal of the fifth controlled switch, turning on the fifth controlled switch to ground the controlled terminal of the third controlled switch, thereby turning on the third controlled switch; When the second input terminal is connected to the second power supply, the second level inversion circuit outputs a low level to the controlled terminal of the fifth controlled switch to turn off the fifth controlled switch. When the fifth controlled switch is turned off, the third controlled switch is turned off.

5. The power supply switching circuit according to claim 4, wherein: The second level flipping circuit includes a sixth controlled switch, one end of the sixth controlled switch is connected to the first input end and to the controlled end of the fifth controlled switch via a second resistor, the other end of the sixth controlled switch is grounded, and the controlled end of the sixth controlled switch is connected to the second input end; When the second input terminal is not connected to the second power supply, the sixth controlled switch is turned off, and the controlled terminal of the fifth controlled switch is set to a high level and turned on; When the second input terminal is connected to the second power supply, the sixth controlled switch is turned on, and the controlled terminal of the fifth controlled switch is grounded and turned off.

6. The power supply switching circuit according to claim 3, wherein: The controlled end of the first controlled switch is connected to the output end of the power supply switching circuit through a third resistor. When the fourth controlled switch is turned on, the controlled end of the first controlled switch is grounded.

7. The power supply switching circuit according to claim 4, wherein: The controlled end of the third controlled switch is connected to the first input end via a fourth resistor. When the fifth controlled switch is turned on, the controlled end of the third controlled switch is grounded. When the fifth controlled switch is turned off, the controlled end of the third controlled switch is connected to the first power supply of the first input end via the fourth resistor.

8. The power supply switching circuit according to any one of claims 1 to 7, wherein: The first controlled switch, the second controlled switch and the third controlled switch are MOS transistors, and the fourth controlled switch, the fifth controlled switch and the sixth controlled switch are triodes.

9. An electronic device, characterized in that: include: load; a first power source; The power supply switching circuit according to any one of claims 1 to 8, connected to the first power supply and the load; The power supply switching circuit is further configured to connect to a second power source, and when the second power source is not connected, the first power source outputs electrical energy, while when the second power source is connected, the second power source outputs electrical energy.

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