A power switching circuit, electronic device

Abstract

The application provides a power switching circuit and an electronic device, and relates to the technical field of circuits.The power switching circuit comprises a first power signal input end, a second power signal input end, a first switch sub-circuit for controlling signals input by the first power signal input end to be output from an output sub-circuit, a second switch sub-circuit for controlling signals input by the second power signal input end to be output from the output sub-circuit, a comparison sub-circuit for controlling the first transistor to be turned on or turned off or for controlling the second transistor to be turned on or turned off, and the output sub-circuit for outputting electrical signals transmitted by the first switch sub-circuit or outputting electrical signals transmitted by the second switch sub-circuit.The power switching circuit provided in the application has a low resistance between the source and the drain of the transistor when the transistor is turned on, and the energy loss in the power switching circuit is low.

Description

Technical Field

[0001] This application relates to the field of circuits, and more particularly to a power switching circuit and electronic equipment. Background Technology

[0002] With the development of technology, the types and production of electronic devices are increasing, such as laptops, wireless routers, PDAs, digital cameras, and mobile phones. Due to the limitations of the weight, size, and lithium battery capacity of electronic devices, lithium batteries cannot meet the demand for continuous power supply for a long time. Therefore, most electronic products generally use a dual power supply design.

[0003] In related technologies, dual power supply switching circuits are relatively complex or have high energy losses. Summary of the Invention

[0004] Embodiments of this application provide a power switching circuit and an electronic device. The power switching circuit is relatively simple and has low on-resistance and low energy loss.

[0005] The embodiments of this application adopt the following technical solutions:

[0006] In a first aspect, embodiments of this application provide a power switching circuit, the power switching circuit comprising:

[0007] First power signal input terminal;

[0008] Second power signal input terminal;

[0009] A first switching sub-circuit, coupled to the first power signal input terminal, includes a first transistor. The first switching sub-circuit is used to control the signal input to the first power signal input terminal to be output from the output sub-circuit.

[0010] The second switching sub-circuit, coupled to the second power signal input terminal, includes a second transistor. The second switching sub-circuit is used to control the signal input to the second power signal input terminal to be output from the output sub-circuit.

[0011] The comparator circuit is coupled to the first transistor, the second transistor, the first power signal input terminal and the second power signal input terminal respectively, and is used to control the first transistor to be turned on or off, or to control the second transistor to be turned on or off.

[0012] The output sub-circuit is coupled to the first switch circuit and the second switch circuit, and is used to output the electrical signal transmitted by the first switch sub-circuit or the electrical signal transmitted by the second switch sub-circuit.

[0013] Optionally, the first transistor includes a P-type field-effect transistor, and the second transistor includes a P-type field-effect transistor.

[0014] Optionally, the first switching sub-circuit includes the first transistor and the first resistor;

[0015] The drain of the first transistor is coupled to the first power signal input terminal;

[0016] The source of the first transistor is coupled to the output sub-circuit;

[0017] The gate of the first transistor is coupled to the comparator circuit;

[0018] The first end of the first resistor is coupled to the gate of the first transistor, and the second end of the first resistor is coupled to the second power signal input terminal.

[0019] Optionally, the second switching sub-circuit includes: a second transistor, a second resistor, a third resistor, and a third capacitor;

[0020] The drain of the second transistor is coupled to the output sub-circuit;

[0021] The source of the second transistor is coupled to the second power signal input terminal;

[0022] The gate of the second transistor is coupled to the first terminal of the third resistor;

[0023] The second terminal of the third resistor is coupled to the comparator circuit.

[0024] The first end of the second resistor is coupled to the gate of the second transistor, and the second end of the second resistor is coupled to the second power signal input terminal;

[0025] The first end of the third capacitor is coupled to the gate of the second transistor, and the second end of the third capacitor is coupled to the second power signal input terminal.

[0026] Optionally, the second switching circuit further includes: a first capacitor and a second capacitor;

[0027] The first terminal of the first capacitor is coupled to the second power signal input terminal, and the second terminal of the first capacitor is grounded.

[0028] The first terminal of the second capacitor is coupled to the second power signal input terminal, and the second terminal of the second capacitor is grounded.

[0029] Optionally, the output sub-circuit includes a post-stage voltage regulator module, which is used to stabilize the electrical signal transmitted by the first switching sub-circuit or the electrical signal transmitted by the second switching sub-circuit.

[0030] Optionally, the comparator sub-circuit includes: a first voltage comparator and a second voltage comparator;

[0031] The first voltage comparator is used to output a first control signal based on the signal input at the first power signal input terminal. The first control signal is used to control the conduction or cutoff of the first switching circuit.

[0032] The second voltage comparator is used to output a second control signal based on the signal input at the second power signal input terminal. The second control signal is used to control the conduction or cutoff of the second switching circuit.

[0033] Optionally, the comparator circuit further includes: a fourth resistor, a sixth resistor, an eighth resistor, and a ninth resistor;

[0034] The first input terminal of the first voltage comparator is coupled to the first terminal of the fourth resistor, and the second terminal of the fourth resistor is coupled to the first power signal input terminal.

[0035] The second input terminal of the first voltage comparator is coupled to the first terminal of the sixth resistor, and the second terminal of the sixth resistor is coupled to the second power signal input terminal; the second input terminal of the first voltage comparator is coupled to the first terminal of the eighth resistor, and the second terminal of the eighth resistor is grounded;

[0036] The output of the first voltage comparator is coupled to the first sub-switch circuit;

[0037] The first end of the ninth resistor is coupled to the second end of the first voltage comparator, and the second end of the ninth resistor is coupled to the output end of the first voltage comparator.

[0038] Optionally, the comparator circuit further includes: a fifth resistor, a seventh resistor, and a fourth capacitor;

[0039] The first input terminal of the second voltage comparator is coupled to the first terminal of the fifth resistor, and the second terminal of the fifth resistor is coupled to the output sub-circuit; the first input terminal of the second voltage comparator is coupled to the first terminal of the fourth capacitor, and the second terminal of the fourth capacitor is coupled to the second power signal input terminal; the first input terminal of the second voltage comparator is coupled to the first terminal of the seventh resistor, and the second terminal of the seventh resistor is grounded;

[0040] The second input terminal of the second voltage comparator is coupled to the first terminal of the tenth resistor, and the second terminal of the tenth resistor is coupled to the first power signal input terminal;

[0041] The output of the second voltage comparator is coupled to the second sub-switch circuit.

[0042] Secondly, embodiments of this application provide an electronic device, characterized in that it includes any of the power switching circuits described in the first aspect.

[0043] The power switching circuit provided in this application embodiment controls the conduction or cutoff of the first power signal input terminal through a first transistor; and controls the conduction or cutoff of the second power signal input terminal through a second transistor. Compared with traditional diode control, the resistance between the source and drain of the transistor is lower when it is on, resulting in less energy loss; and the transistor will not leak current when the voltage of the second power signal input terminal is greater than the voltage of the first power signal input terminal. Attached Figure Description

[0044] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0045] Figure 1 This is a schematic diagram of a power switching circuit provided in an embodiment of this application;

[0046] Figure 2 A schematic diagram of a switch sub-circuit provided in an embodiment of this application;

[0047] Figure 3 A schematic diagram of a switch sub-circuit provided in an embodiment of this application;

[0048] Figure 4 A schematic diagram of a comparator circuit provided in an embodiment of this application;

[0049] Figure 5 A schematic diagram of a comparator circuit provided in an embodiment of this application;

[0050] Figure 6 A schematic diagram of an output sub-circuit provided in an embodiment of this application;

[0051] Figure 7 A schematic diagram of a P-type field-effect transistor provided in an embodiment of this application;

[0052] Figure 8 This is a schematic diagram of an integrated voltage comparator provided in an embodiment of this application;

[0053] Figure 9 This is a schematic diagram of a power switching circuit provided in an embodiment of this application. Detailed Implementation

[0054] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0055] In the embodiments of this application, the terms "first", "second", "third", "fourth" are used to distinguish the same or similar items with essentially the same function and effect, only for the purpose of clearly describing the technical solution of the embodiments of this application, and should not be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated.

[0056] In the embodiments of this application, "multiple" means two or more, and "at least one" means one or more, unless otherwise explicitly defined.

[0057] In embodiments of the present invention, the term "coupled" may refer to two components being directly electrically connected, or to two components being electrically connected via one or more other components.

[0058] It should be noted that the various data-related processes in the embodiments of this application are carried out in compliance with the relevant data protection laws and policies of the country where the location is located, and with the authorization granted by the owner of the corresponding device.

[0059] This application provides a power switching circuit, referencing... Figure 1 The power switching circuit includes:

[0060] First power signal input terminal 101; Second power signal input terminal 102;

[0061] The first switch sub-circuit 103 is coupled to the first power signal input terminal 101 and includes the first transistor V1. The first switch sub-circuit 103 is used to control the signal input from the first power signal input terminal 101 to be output from the output sub-circuit 106.

[0062] The second switch sub-circuit 104 is coupled to the second power signal input terminal 102 and includes the second transistor V2. The second switch sub-circuit 104 is used to control the signal input from the second power signal input terminal 102 to be output from the output sub-circuit 106.

[0063] The comparator circuit 105 is coupled to the first transistor V1, the second transistor V2, the first power signal input 101 and the second power signal input 102 respectively, and is used to control the first transistor V1 to be turned on or off, or to control the second transistor V2 to be turned on or off.

[0064] The output sub-circuit 106 is coupled to the first switch circuit 103 and the second switch circuit 104, and is used to output the electrical signal transmitted by the first switch sub-circuit 103 or the electrical signal transmitted by the second switch sub-circuit 104.

[0065] The power switching circuit provided in this application is applied to electronic devices. This application does not specifically limit the type of electronic device. For example, electronic devices include, but are not limited to, laptops, wireless routers, PDAs, digital cameras, wireless communication devices, and mobile phones.

[0066] Electronic devices include a battery power source, for example, a lithium-ion battery power source. However, due to limitations in product weight, size, and lithium-ion battery capacity, the battery power source cannot meet the demand for continuous power supply over a long period of time. Therefore, an external power source is required for the electronic device, and the power switching circuit is configured to switch between the internal battery power source and the external power source.

[0067] The voltage range of the external power supply can be 8.4V to 12V. For example, the voltage of the external power supply can be 8.4V, 9V, 9.5V, 10V, 10.5V, 11V, 11.5V, or 12V. The voltage range of the internal battery power supply can be 10.8V to 16.8V. For example, the voltage of the internal battery power supply can be 10.8V, 11.8V, 12.8V, 13.8V, 14.8V, 15.8V, or 16.8V.

[0068] The following example uses the first power signal input terminal 101 as an external power source and the second power signal input terminal 102 as an internal battery power source.

[0069] The signal input to the power signal input terminal is current. The first power signal input terminal 101 or the second power signal input terminal 102 serves as the power source to supply power to the load inside the electronic device.

[0070] The first power signal input terminal 101 is coupled to the first switch sub-circuit 103, and the first switch sub-circuit 103 is used to control the signal input from the first power signal input terminal 101 to be output from the output sub-circuit 106.

[0071] The first switching sub-circuit 103 includes a first transistor V1. The first switching sub-circuit 103 controls the signal input to the first power signal input terminal 101 to be output from the output sub-circuit 106, including at least the following cases:

[0072] First, when the first transistor V1 is turned on, the first switch sub-circuit 103 controls the signal input to the first power signal input terminal 101 to be output from the output sub-circuit 106.

[0073] Second, when the first transistor V1 is off, the first power signal input terminal 101, as an external power supply, has no signal input, that is, it is not connected to an external power supply.

[0074] The second power signal input terminal 102 is coupled to the second switch sub-circuit 104, and the second switch sub-circuit 104 is used to control the signal input from the second power signal input terminal 102 to be output from the output sub-circuit 106.

[0075] The second switching sub-circuit 104 includes a second transistor V2. The first switching sub-circuit 104 controls the signal input to the second power signal input terminal 102 to be output from the output sub-circuit 106, including at least the following cases:

[0076] First, when the second transistor V2 is turned on, the second switch sub-circuit 104 controls the signal input to the second power signal input terminal 102 to be output from the output sub-circuit 106.

[0077] Second, when the second transistor V2 is turned off, the second switch sub-circuit 104 controls the signal input to the second power signal input terminal 102 to be turned off.

[0078] The first transistor V1 is a P-type transistor. Taking the voltage of the first level signal as being less than the voltage of the second level signal as an example, the first transistor V1 is turned on when the first level signal is input to its gate; and the first transistor V1 is turned off when the second level signal is input to its gate.

[0079] Similarly, the second transistor V2 is a P-type transistor. When a first-level signal is input to the gate of the second transistor V2, the second transistor V2 is turned on; when a second-level signal is input to the gate of the second transistor V2, the second transistor V2 is turned off.

[0080] The following explanation assumes that both the first transistor V1 and the second transistor V2 are P-type transistors.

[0081] In addition, the comparator circuit 105 includes a first voltage comparator D1 and a second voltage comparator D2.

[0082] The first voltage comparator D1 is used to output a first control signal, which is used to control the first transistor V1 to turn on or off. The first control signal includes a first level signal and a second level signal. When the first control signal output by the first voltage comparator D1 is the first level signal, the first transistor V1 is turned on; when the first control signal output by the first voltage comparator D1 is the second level signal, the first transistor V1 is turned off.

[0083] The second voltage comparator D2 is used to output a second control signal, which is used to control the conduction or cutoff of the second transistor V2. The second control signal includes a first level signal and a second level signal. When the second control signal output by the second voltage comparator D2 is the first level signal, the second transistor V2 is turned on; when the second control signal output by the second voltage comparator D2 is the second level signal, the second transistor V2 is turned off.

[0084] It should be noted that the first voltage comparator D1 and the second voltage comparator D2 can be two independent voltage comparators, or, as shown in the following figure... Figure 8 The first voltage comparator D1 and the second voltage comparator D2 can be integrated into a single electronic component.

[0085] The power supply for the first voltage comparator D1 can be the internal battery power supply, and the first voltage comparator D1 is grounded; the power supply for the second voltage comparator D2 can be the internal battery power supply, and the second voltage comparator D2 is grounded.

[0086] Finally, the output sub-circuit 106 is used to output the electrical signal transmitted by the first switch sub-circuit 103 or the electrical signal transmitted by the second switch sub-circuit 104.

[0087] For example, the electrical signal is current, the output sub-circuit 106 is connected to the load 107, and the output sub-circuit 106 is used to output the input signal of the first current signal input terminal 101 transmitted by the first switch sub-circuit 103; or, the output sub-circuit 106 is used to output the input signal of the first current signal input terminal 102 transmitted by the second switch sub-circuit 104.

[0088] The power switching circuit provided in this application includes, but is not limited to, the following operating states:

[0089] In the first state, when neither the first power signal input terminal 101 nor the second power signal input terminal 102 receives a signal, the first power signal input terminal 101 receives a signal, the first voltage comparator D1 outputs a first-level signal, and the second voltage comparator D2 outputs a second-level signal; the first transistor V1 is turned on, and the second transistor V2 is turned off; the first switch sub-circuit 103 is turned on, and the second switch sub-circuit 104 is turned off; the output sub-circuit 106 outputs the signal input to the first power signal input terminal 101. For example, this is the power-on state when the electronic device is connected to an external power source.

[0090] In the second state, when neither the first power signal input terminal 101 nor the second power signal input terminal 102 receives a signal, the second power signal input terminal 102 receives a signal, the first voltage comparator D1 outputs a second-level signal, and the second voltage comparator D2 outputs a first-level signal; the first transistor V1 is cut off, and the second transistor V2 is turned on; the first switch sub-circuit 103 is cut off, and the second switch sub-circuit 104 is turned on; the output sub-circuit 106 outputs the signal input to the second power signal input terminal 102. For example, this is the electronic device being powered on when only an internal battery is connected.

[0091] In the third state, when a signal is input at the second power signal input terminal 102, a signal is input at the first power signal input terminal 101. The first voltage comparator D1 outputs a first-level signal, and the second voltage comparator D2 outputs a second-level signal. The first transistor V1 is turned on, and the second transistor V2 is turned off. The first switching sub-circuit 103 is turned on, and the second switching sub-circuit 104 is turned off. The output sub-circuit 106 switches to output the signal input at the first power signal input terminal 101. For example, this is the case when the electronic device is connected to an external power source.

[0092] In the fourth state, when a signal is input to the first power signal input terminal 102, the first power signal input terminal 101 stops receiving signals, the first voltage comparator D1 outputs a second-level signal, and the second voltage comparator D2 outputs a first-level signal; the first transistor V1 is turned off, and the second transistor V2 is turned on; the first switch sub-circuit 103 is turned off, and the second switch sub-circuit 104 is turned on; the output sub-circuit 106 switches to output the signal input to the second power signal input terminal 102. For example, the electronic device stops connecting to an external power source.

[0093] The power switching circuit provided in this application embodiment controls the conduction or cutoff of the first power signal input terminal 101 through the first transistor V1; and controls the conduction or cutoff of the second power signal input terminal 102 through the second transistor V2. Compared with traditional diode control, the resistance between the source and drain of the transistor is lower when it is on, resulting in less energy loss; and the transistor will not leak current when the voltage of the power supply is greater than the voltage of the external power supply.

[0094] Figure 9 A schematic diagram of a specific power switching circuit provided by an embodiment of the present invention is shown, and its various sub-circuits are described in detail below.

[0095] Optionally, the first transistor V1 includes a P-type field-effect transistor, and the second transistor V2 includes a P-type field-effect transistor.

[0096] P-type field-effect transistors include P-type metal-oxide-semiconductor field-effect transistors (MOSFETs).

[0097] This application does not specifically limit the model of the P-type field-effect transistor in its embodiments; for example, Figure 7 A specific eight-pin field-effect transistor is shown, which has eight pins, four of which are drains, three of which are sources, and one of which is a gate.

[0098] The first transistor V1 and the second transistor V2 use P-type field-effect transistors. When the P-type field-effect transistor is turned on, the resistance between the source and drain is low, resulting in lower energy loss in the power switching circuit. In addition, the P-type field-effect transistor has a simpler integration process, lower cost, and a wider operating power supply voltage range.

[0099] Optional, refer to Figure 2 The first switching sub-circuit 103 includes a first transistor V1 and a first resistor R1; the drain D of the first transistor V1 is coupled to the first power signal input terminal 101.

[0100] The source S of the first transistor V1 is coupled to the output sub-circuit 106;

[0101] The gate G of the first transistor V1 is coupled to the comparator circuit 105;

[0102] The first end of the first resistor R1 is coupled to the gate of the first transistor V1, and the second end of the first resistor R1 is coupled to the second power signal input terminal 102.

[0103] The drain D of the first transistor V1 is coupled to the first power signal input terminal 101, and the second stage S of the first transistor V1 is coupled to the output sub-circuit 106. When the first control signal received by the gate G of the first transistor V1 is a first level signal, the first transistor V1 is turned on, and the input signal of the first power signal input terminal 101 is output from the output sub-circuit 106. When the first control signal received by the gate G of the first transistor V1 is a second level signal, the first transistor V1 is turned off, and the first power signal input terminal 101, as an external power supply, has no signal input.

[0104] The gate G of the first transistor V1 is coupled to the second power signal input terminal 102 through the first resistor R1, which is used to increase the potential of the gate G of the first transistor V1, ensuring that the gate G of the first transistor V1 is turned on under the first level signal and turned off under the second level signal.

[0105] The resistance value of the first resistor R1 can be set according to the actual circuit requirements. For example, the resistance value of the first resistor R1 can be 4.7KΩ.

[0106] The power switching circuit provided in this application embodiment controls the conduction or cutoff of the first power signal input terminal 101 through the first transistor V1. Compared with traditional diode control, the resistance between the source and drain of the transistor is lower when it is on, resulting in less energy loss. When the voltage of the second power signal input terminal 102 is greater than the voltage of the first power signal input terminal 101, the transistor will not leak current.

[0107] Optional, refer to Figure 3 The second switch sub-circuit 104 includes: a second transistor V2, a second resistor R2, a third resistor R3, and a third capacitor C3;

[0108] The drain D of the second transistor V2 is coupled to the output sub-circuit 106;

[0109] The source S of the second transistor V2 is coupled to the second power signal input terminal 102;

[0110] The gate G of the second transistor V2 is coupled to the first end of the third resistor R3;

[0111] The second terminal of the third resistor R3 is coupled to the comparator circuit 105;

[0112] The first end of the second resistor R2 is coupled to the gate of the second transistor V2, and the second end of the second resistor R2 is coupled to the second power signal input terminal 102.

[0113] The first terminal of the third capacitor C3 is coupled to the gate of the second transistor V2, and the second terminal of the third capacitor C3 is coupled to the second power signal input terminal 102.

[0114] The drain D of the second transistor V2 is coupled to the output sub-circuit 106, and the second stage S of the first transistor V1 is coupled to the second power signal input terminal 102. When the second control signal received by the gate G of the second transistor V2 is a first level signal, the second transistor V2 is turned on, and the input signal of the second power signal input terminal 102 is output from the output sub-circuit 106; when the second control signal received by the gate G of the second transistor V2 is a second level signal, the second transistor V2 is turned off, and the input signal of the second power signal input terminal 102 is cut off.

[0115] The third resistor R3 is used to delay the input of the second control signal, and the second resistor R2 and the third capacitor C3 are used to delay the increase of the potential of the gate G of the first transistor V1, so as to ensure the smooth conduction of the second transistor V2 and thus ensure the stability of the circuit.

[0116] The resistance values ​​of the second resistor R2, the third resistor R3, and the third capacitor C3 can be set according to the actual circuit requirements. For example, the resistance value of the second resistor R2 can be 1KΩ, the resistance value of the third resistor R3 can be 4.7KΩ, and the capacitance value of the third capacitor C3 can be 0.1μF.

[0117] The power switching circuit provided in this application embodiment controls the conduction or cutoff of the second power signal input terminal 102 through the second transistor V2. Compared with traditional diode control, the resistance between the source and drain of the transistor is lower when it is on, resulting in less energy loss. When the voltage of the power supply is greater than the voltage of the external power supply, the transistor will not leak current.

[0118] Optional, refer to Figure 3 The second switching circuit 104 also includes: a first capacitor C1 and a second capacitor C2;

[0119] The first terminal of the first capacitor C1 is coupled to the second power signal input terminal 102, and the second terminal of the first capacitor C1 is grounded.

[0120] The first end of the second capacitor C2 is coupled to the second power signal input terminal 102, and the second end of the second capacitor C2 is grounded.

[0121] The first capacitor C1 and the second capacitor C2 are used to store energy at the second power signal input terminal 102, ensuring voltage stability when the voltage at the second power signal input terminal 102 changes.

[0122] The capacitance values ​​of the first capacitor C1 and the second capacitor C2 can be set according to the actual circuit requirements. For example, the capacitance value of the first capacitor C1 can be 10μF and the capacitance value of the second capacitor C2 can be 10μF.

[0123] Optional, refer to Figure 6 The output sub-circuit 106 includes a post-stage voltage regulator module 201, which is used to stabilize the electrical signal transmitted by the first switching sub-circuit 103 or the electrical signal transmitted by the second switching sub-circuit 104.

[0124] Figure 6 The specific circuit of the subsequent voltage regulator circuit is not shown in the figure. The specific circuit can be referred to in the prior art and will not affect the core inventive point of this application.

[0125] After passing through the subsequent voltage regulator circuit 201, a stable voltage signal can be output, preventing damage to the load 107 inside the electronic device due to voltage changes during power switching.

[0126] Optionally, the comparator circuit includes: a first voltage comparator D1 and a second voltage comparator D2;

[0127] The first voltage comparator D1 is used to output a first control signal based on the signal input at the first power signal input terminal 101. The first control signal is used to control the conduction or cutoff of the first switching circuit 103. The second voltage comparator D2 is used to output a second control signal based on the signal input at the second power signal input terminal 102. The second control signal is used to control the conduction or cutoff of the second switching circuit 104.

[0128] The first voltage comparator D1 is used to output a first control signal, which is used to control the conduction or cutoff of the first transistor V1. The first control signal includes a first level signal and a second level signal. When the first control signal output by the first voltage comparator D1 is the first level signal, the first transistor V1 is turned on; when the first control signal output by the first voltage comparator D1 is the second level signal, the first transistor V1 is turned off.

[0129] The second voltage comparator D2 is used to output a second control signal, which is used to control the conduction or cutoff of the second transistor V2. The second control signal includes a first level signal and a second level signal. When the second control signal output by the second voltage comparator D2 is the second level signal, the second transistor V2 is turned on; when the second control signal output by the second voltage comparator D2 is the second level signal, the second transistor V2 is turned off.

[0130] The first switching sub-circuit 103 is controlled by the first voltage comparator D1, and the second switching sub-circuit 104 is controlled by the second voltage comparator D2. Different voltage comparators are used to control different power signal terminals, making the power switching control in the power switching circuit more precise.

[0131] Optionally, the comparator circuit 105 may also include: a fourth resistor R4, a sixth resistor R6, an eighth resistor R8, and a ninth resistor R9;

[0132] The first input terminal IN1 of the first voltage comparator D1 is coupled to the first terminal of the fourth resistor R4, and the second terminal of the fourth resistor R4 is coupled to the first power signal input terminal 101.

[0133] The second input terminal IN1+ of the first voltage comparator D1 is coupled to the first terminal of the sixth resistor R6, and the second terminal of the sixth resistor R6 is coupled to the second power signal input terminal 102; the second input terminal IN1+ of the first voltage comparator D1 is coupled to the first terminal of the eighth resistor R8, and the second terminal of the eighth resistor R8 is grounded.

[0134] The output terminal OUT of the first voltage comparator D1 is coupled to the first sub-switch circuit 103;

[0135] The first terminal of the ninth resistor R9 is coupled to the second terminal of the first voltage comparator D1, and the second terminal of the ninth resistor R9 is coupled to the output terminal of the first voltage comparator D1.

[0136] The first input terminal IN1- of the first voltage comparator D1 is coupled to the first power signal input terminal 101 through the fourth resistor R4. The input voltage of the first power signal input terminal 101 is reduced by the voltage divider of the fourth resistor R4, and in this application, the voltage reduction is as low as 8.4V. When a signal is input to the first power signal input terminal 101, the voltage value received by the first input terminal IN1- of the first voltage comparator D1 is 8.4V to 12V; when no signal is input to the first power signal input terminal 101, the voltage value received by the first input terminal IN1- of the first voltage comparator D1 is 0V.

[0137] The second power signal input terminal 102 is grounded through the sixth resistor R6 and the eighth resistor R8. The sixth resistor R6 and the eighth resistor R8 form a voltage divider. Taking the equal resistance values ​​of the sixth resistor R6 and the eighth resistor R8 as an example, the voltage divided by the sixth resistor R6 is half of the input signal voltage to the second power signal input terminal 102. The second input terminal IN1+ of the first voltage comparator D1 is connected between the sixth resistor R6 and the eighth resistor R8. The voltage received by the second input terminal IN1+ is the voltage divided by the sixth resistor R6. The voltage value received by the second input terminal IN1+ of the first voltage comparator D1 is 5.5V to 8.4V.

[0138] The second input terminal IN1+ and the output terminal OUT of the first voltage comparator D1 are connected by the ninth resistor R9. The ninth resistor R9 acts as a hysteresis circuit, also known as a delay circuit. A voltage comparator with a hysteresis circuit is called a hysteresis comparator. The hysteresis comparator has better anti-interference performance. When the voltage at the second input terminal IN1+ changes, the ninth resistor R9 can delay the response of the first voltage comparator D1 to the voltage change at the second input terminal IN1+, avoiding multiple jumps in the output signal at the output terminal OUT when the second input terminal IN1+ produces a small change near the threshold of 8.4V.

[0139] The operating states of the first voltage comparator D1 include, but are not limited to, the following:

[0140] First, when a signal is input to the first power signal input terminal 101, the voltage value received at the first input terminal IN1- of the first voltage comparator D1 is 8.4V to 12V, and the voltage value received at the second input terminal IN1+ of the first voltage comparator D1 is 5.5V to 8.4V. Since the voltage value at the first input terminal IN1- is greater than the voltage value at the second input terminal IN+, the output terminal OUT of the first voltage comparator D1 outputs a first level signal, thereby turning on the first transistor V1.

[0141] Second, when there is no input signal at the first power signal input terminal 101, the voltage value received at the first input terminal IN1- of the first voltage comparator D1 is 0V, and the voltage value received at the second input terminal IN1+ of the first voltage comparator D1 is 5.5V to 8.4V. Since the voltage value at the first input terminal IN1- is less than the voltage value at the second input terminal IN1+, the output terminal OUT of the first voltage comparator D1 outputs a second level signal, thereby turning off the first transistor V1.

[0142] The resistance values ​​of the fourth resistor R4, the sixth resistor R6, the eighth resistor R8, and the ninth resistor R9 can be set according to the actual circuit requirements. For example, the resistance value of the fourth resistor R4 can be 1kΩ, the resistance value of the sixth resistor R6 can be 10kΩ, the resistance value of the eighth resistor R8 can be 10kΩ, and the resistance value of the ninth resistor R9 can be 20kΩ.

[0143] The power switching circuit provided in this application embodiment controls the conduction or cutoff of the first transistor V1 through the first voltage comparator D1, and controls the conduction or cutoff of the first power signal input terminal 101 through the first transistor V1. Compared with traditional diode control, the transistor has a lower on-resistance and less energy loss. When the voltage of the second power signal input terminal 102 is greater than the voltage of the first power signal input terminal 101, the transistor will not leak current.

[0144] Optional, refer to Figure 5 The comparator circuit 105 also includes: a fifth resistor R5, a seventh resistor R7, a tenth resistor R10, and a fourth capacitor C4.

[0145] The first input terminal IN2- of the second voltage comparator D2 is coupled to the first terminal of the fifth resistor R5, and the second terminal of the fifth resistor R5 is coupled to the output sub-circuit 106; the first input terminal IN2- of the second voltage comparator D2 is coupled to the first terminal of the fourth capacitor C4, and the second terminal of the fourth capacitor C4 is coupled to the second power signal input terminal 102; the first input terminal IN2- of the second voltage comparator D2 is coupled to the first terminal of the seventh resistor R7, and the second terminal of the seventh resistor R7 is grounded.

[0146] The second input terminal IN2+ of the second voltage comparator D2 is coupled to the first terminal of the tenth resistor R10, and the second terminal of the tenth resistor R10 is coupled to the first power signal input terminal 101.

[0147] The output terminal OUT of the second voltage comparator D2 is coupled to the second sub-switch circuit 104.

[0148] For example, the output signal of the output sub-circuit 106 can be the output signal after passing through the subsequent voltage regulator circuit 201, making the output signal more stable. For example, the voltage of the output signal is stabilized at 12V.

[0149] The output sub-circuit 106 is grounded through the fifth resistor R5 and the seventh resistor R7. The fifth resistor R5 and the seventh resistor R7 form a voltage divider, with the voltage range of the seventh resistor R7 being 4V to 5.5V. For example, the voltage division of the seventh resistor R7 could be 4V, 4.2V, 4.4V, 4.6V, 4.8V, 5V, 5.2V, 5.4V, or 5.5V. Here, we take the voltage division value of the seventh resistor R7 as 5V. Generally, the voltage division will not reach 5.5V to avoid reaching the critical threshold and preventing the output terminal OUT from abruptly changing when the second input terminal IN2+ changes slightly.

[0150] The fifth resistor R5 and the seventh resistor R7 are coupled to the second power signal input terminal 102 through the fourth capacitor C4, which is used for further voltage regulation of the voltage divided by the seventh resistor R7.

[0151] The first input terminal IN1 of the second voltage comparator D2 is connected between the fifth resistor R5 and the seventh resistor R7. The voltage received at the first input terminal IN1 is the voltage drop across the seventh resistor R7. The voltage received at the first input terminal IN2 of the second voltage comparator D2 is a stable 5V.

[0152] The second input terminal IN2+ of the second voltage comparator D2 is coupled to the first power signal input terminal 101 through the fourth resistor R4. The input voltage of the first power signal input terminal 101 is reduced by the voltage divider of the fourth resistor R4, and in this application, the voltage reduction is as low as 8.4V. When a signal is input to the first power signal input terminal 101, the voltage value received by the second input terminal IN2+ of the second voltage comparator D2 is 8.4V to 12V; when no signal is input to the first power signal input terminal 101, the voltage value received by the second input terminal IN2+ of the second voltage comparator D2 is 0V.

[0153] The operating states of the second voltage comparator D2 include, but are not limited to, the following:

[0154] First, when a signal is input to the first power signal input terminal 101, the voltage value received at the first input terminal IN2- of the second voltage comparator D2 is 5V, the voltage value received at the second input terminal IN2+ of the second voltage comparator D2 is 8.4V to 12V, the voltage value at the first input terminal IN3- is less than the voltage value at the second input terminal IN2+, the output terminal OUT of the first voltage comparator D1 outputs a second level signal, and thus the second transistor V2 is turned off.

[0155] Second, when there is no input signal at the first power signal input terminal 101, the voltage value received at the first input terminal IN2- of the second voltage comparator D2 is 5V, the voltage value received at the second input terminal IN2+ of the second voltage comparator D2 is 0V, the voltage value at the first input terminal IN3- is greater than the voltage value at the second input terminal IN2+, the output terminal OUT of the second voltage comparator D2 outputs a first level signal, and then the second transistor V2 is turned on.

[0156] The resistance values ​​of the fifth resistor R5, the seventh resistor R7, the tenth resistor R10, and the fourth capacitor C4 can be set according to the actual circuit requirements. For example, the resistance value of the fifth resistor R5 can be 8.49kΩ, the resistance value of the seventh resistor R7 can be 4.7kΩ, the resistance value of the tenth resistor R10 can be 1kΩ, and the capacitance value of the fourth capacitor C4 can be 0.01μF.

[0157] The power switching circuit provided in this application embodiment controls the conduction or cutoff of the second transistor V2 through the second voltage comparator D2, and controls the conduction or cutoff of the second power signal input terminal 102 through the second transistor V2. Compared with traditional diode control, the resistance between the source and drain of the transistor is lower when it is on, resulting in less energy loss. When the voltage of the second power signal input terminal 102 is greater than the voltage of the first power signal input terminal 101, the transistor will not leak current.

[0158] This application provides an electronic device including the power switching circuit described above.

[0159] This application does not specifically limit the type of electronic device. For example, electronic devices include, but are not limited to, laptops, wireless routers, PDAs, digital cameras, wireless communication devices, and mobile phones.

[0160] The electronic device provided in this application embodiment controls the conduction or cutoff of the second power signal input terminal 102 through the second transistor V2. Compared with the traditional diode control, the resistance between the source and drain of the transistor is lower when it is on, resulting in less energy loss. When the voltage of the second power signal input terminal 102 is greater than the voltage of the first power signal input terminal 101, the transistor will not leak current.

[0161] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A power switching circuit, characterized in that, include: First power signal input terminal; Second power signal input terminal; A first switching sub-circuit, coupled to the first power signal input terminal, includes a first transistor. The first switching sub-circuit is used to control the signal input to the first power signal input terminal to be output from the output sub-circuit. The second switching sub-circuit, coupled to the second power signal input terminal, includes a second transistor. The second switching sub-circuit is used to control the signal input to the second power signal input terminal to be output from the output sub-circuit. The comparator circuit is coupled to the first transistor, the second transistor, the first power signal input terminal and the second power signal input terminal respectively, and is used to control the first transistor to be turned on or off, or to control the second transistor to be turned on or off. The output sub-circuit is coupled to the first switch sub-circuit and the second switch sub-circuit, and is used to output the electrical signal transmitted by the first switch sub-circuit or the electrical signal transmitted by the second switch sub-circuit. The first switching sub-circuit includes the first transistor and the first resistor; The drain of the first transistor is coupled to the first power signal input terminal; The source of the first transistor is coupled to the output sub-circuit; The gate of the first transistor is coupled to the comparator circuit; The first end of the first resistor is coupled to the gate of the first transistor, and the second end of the first resistor is coupled to the second power signal input terminal.

2. The power switching circuit according to claim 1, characterized in that, The first transistor includes a P-type field-effect transistor, and the second transistor includes a P-type field-effect transistor.

3. The power switching circuit according to claim 1, characterized in that, The second switching sub-circuit includes: a second transistor, a second resistor, a third resistor, and a third capacitor; The drain of the second transistor is coupled to the output sub-circuit; The source of the second transistor is coupled to the second power signal input terminal; The gate of the second transistor is coupled to the first terminal of the third resistor; The second terminal of the third resistor is coupled to the comparator circuit. The first end of the second resistor is coupled to the gate of the second transistor, and the second end of the second resistor is coupled to the second power signal input terminal; The first end of the third capacitor is coupled to the gate of the second transistor, and the second end of the third capacitor is coupled to the second power signal input terminal.

4. The power switching circuit according to claim 3, characterized in that, The second switching circuit also includes: a first capacitor and a second capacitor; The first terminal of the first capacitor is coupled to the second power signal input terminal, and the second terminal of the first capacitor is grounded. The first terminal of the second capacitor is coupled to the second power signal input terminal, and the second terminal of the second capacitor is grounded.

5. The power switching circuit according to claim 1, characterized in that, The output sub-circuit includes a post-stage voltage regulator module, which is used to stabilize the electrical signal transmitted by the first switching sub-circuit or the electrical signal transmitted by the second switching sub-circuit.

6. The power switching circuit according to claim 1, characterized in that, The comparator sub-circuit includes: a first voltage comparator and a second voltage comparator; The first voltage comparator is used to output a first control signal based on the signal input at the first power signal input terminal. The first control signal is used to control the conduction or cutoff of the first switching circuit. The second voltage comparator is used to output a second control signal based on the signal input at the second power signal input terminal. The second control signal is used to control the conduction or cutoff of the second switching circuit.

7. The power switching circuit according to claim 6, characterized in that, The comparator circuit further includes: a fourth resistor, a sixth resistor, an eighth resistor, and a ninth resistor; The first input terminal of the first voltage comparator is coupled to the first terminal of the fourth resistor, and the second terminal of the fourth resistor is coupled to the first power signal input terminal. The second input terminal of the first voltage comparator is coupled to the first terminal of the sixth resistor, and the second terminal of the sixth resistor is coupled to the second power signal input terminal; the second input terminal of the first voltage comparator is coupled to the first terminal of the eighth resistor, and the second terminal of the eighth resistor is grounded; The output of the first voltage comparator is coupled to the first switching sub-circuit. The first end of the ninth resistor is coupled to the second end of the first voltage comparator, and the second end of the ninth resistor is coupled to the output end of the first voltage comparator.

8. The power switching circuit according to claim 6, characterized in that, The comparator circuit further includes: a fifth resistor, a seventh resistor, a tenth resistor, and a fourth capacitor; The first input terminal of the second voltage comparator is coupled to the first terminal of the fifth resistor, and the second terminal of the fifth resistor is coupled to the output sub-circuit; the first input terminal of the second voltage comparator is coupled to the first terminal of the fourth capacitor, and the second terminal of the fourth capacitor is coupled to the second power signal input terminal; the first input terminal of the second voltage comparator is coupled to the first terminal of the seventh resistor, and the second terminal of the seventh resistor is grounded; The second input terminal of the second voltage comparator is coupled to the first terminal of the tenth resistor, and the second terminal of the tenth resistor is coupled to the first power signal input terminal; The output of the second voltage comparator is coupled to the second switching sub-circuit.

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

Images