Multi-input power supply switching circuit and electronic equipment

Abstract

The utility model discloses a multi-input power supply switching circuit and electronic equipment, and relates to the technical field of electronic circuits, the circuit comprises K power supply circuits, the power supply priorities of the first power supply circuit to the Kth power supply circuit are sequentially decreased, and each power supply circuit comprises a power supply, a switching circuit and a control circuit; in one power supply circuit, a power supply supplies power to an electric load through a switching circuit, and a control circuit is used for controlling on-off of the switching circuit and comprises a first resistor and a second resistor; the control circuit of the Lth power supply circuit is also used for controlling the Lth power supply circuit to supply power when the Lth power supply circuit is in a power supply available state and the Lth power supply circuit meets the highest priority condition. The switching circuits from the (L + 1) th power supply circuit to the Kth power supply circuit are controlled to be in an off state through a voltage signal which is transmitted by a signal input end led out between the first resistor and the second resistor and serves as a control signal.

Description

Technical Field

[0001] The present application relates to the technical field of electronic circuits, and in particular to a multi-input power supply switching circuit and electronic equipment. Background Art

[0002] The multi-input power supply switching circuit can be divided into the cases where the supply voltages of the multiple input power supplies are the same and the supply voltages are different. When the supply voltages of the multiple input power supplies are different, the high-priority input power supply voltage can be used to control the low-priority switching unit to disconnect the low-priority power supply circuit, thereby realizing the control of the power supply priority of multiple input power supplies. However, when the low-priority input power supply voltage is higher than the high-priority input power supply voltage, the low-priority input power supply voltage of the high-voltage input may also supply power to the output end, which not only fails to meet the power supply priority requirements, but also causes the problem of parallel connection of the input power output, and in severe cases may cause the input power supply to burn out.

[0003] It can be seen that the multi-input power switching circuit in the related art has the problem of insufficient reliability and safety due to easy confusion of priorities. Utility Model Content

[0004] The present application provides a multi-input power supply switching circuit and an electronic device to at least solve the problem of insufficient reliability and safety caused by easy confusion of priorities in the multi-input power supply switching circuit in the related art.

[0005] The present application provides a multi-input power supply switching circuit, comprising: K power supply circuits, wherein K is a positive integer greater than or equal to 2, and the power supply priority decreases from the first power supply circuit to the K-th power supply circuit, and the power supply circuit comprises a power supply, a switch circuit and a control circuit; wherein, in one of the power supply circuits, the power supply supplies power to the power load through the switch circuit, and the control circuit is used to control the on and off of the switch circuit, and the control circuit comprises a first resistor and a second resistor, wherein the first end of the first resistor is connected to the positive electrode of the power supply, the second end of the first resistor is connected to the first end of the second resistor, and the second end of the second resistor is connected to the negative electrode of the power supply and grounded; in the control circuits of the first power supply circuit to the K-1-th power supply circuit, a signal output terminal is led out between the first resistor and the second resistor to pass through the signal output terminal A voltage signal is transmitted as a control signal to the control circuit of at least one of the power supply circuits whose power supply priority is lower than that of the power supply circuit to which it belongs; the control circuit of the Lth power supply circuit is also used to transmit a first control signal to the control circuits of the L+1th power supply circuit to the Kth power supply circuit respectively when the Lth power supply circuit is in a power-available state and the Lth power supply circuit meets the highest priority condition, where L is a positive integer greater than or equal to 1 and less than K, the power-available state is a state in which the power supply is turned on, and the highest priority condition is that the corresponding power supply priority is the highest power supply priority among the power supply priorities of the power supply circuits in the power-available state; the control circuits of the L+1th power supply circuit to the Kth power supply circuit are used to control the switching circuit of the power supply circuit to which they belong to be in an off state in response to the first control signal.

[0006] In an exemplary embodiment, the control circuit further includes a first switching element and a third resistor, wherein the source of the first switching element is grounded, the gate of the first switching element is connected between the first resistor and the second resistor, the drain of the first switching element is connected to the first end of the third resistor, and the second end of the third resistor is connected to the switching circuit; when the power supply circuit to which it belongs is in a power-supply state and the power supply circuit to which it belongs meets the highest priority condition, the first switching element is in an on state; the switching circuit includes a fourth resistor and a second switching element, wherein the first end of the fourth resistor is connected to the second end of the third resistor, the second end of the fourth resistor is connected to the source of the second switching element, the gate of the second switching element is connected between the third resistor and the fourth resistor, and the drain of the second switching element is connected to the first end of the first resistor; when the first switching element is in an on state, the second switching element is also in an on state.

[0007] In an exemplary embodiment, the switching circuit further includes a third switching element, wherein the gate of the third switching element is connected to the gate of the second switching element, the source of the third switching element is connected to the source of the second switching element, and the drain of the third switching element is connected to the output end of the switching circuit. The third switching element is used to prevent the power supply current from flowing to the output end of the multi-input power supply switching circuit when the third switching element is in an off state, and M is a positive integer greater than or equal to 2 and less than or equal to K.

[0008] In an exemplary embodiment, the second switching element and the third switching element are both P-channel metal oxide semiconductor field effect transistors.

[0009] In an exemplary embodiment, in the Nth power supply circuit, the control circuit further includes N-1 fourth switching elements, wherein the gates of the N-1 fourth switching elements are respectively connected to the signal output ends of the control circuit from the 1st power supply circuit to the N-1th power supply circuit, the sources of the N-1 fourth switching elements are grounded, and the drains of the N-1 fourth switching elements are connected between the first resistor and the second resistor. When the control signal transmitted by the signal output end to which any fourth switching element is connected is turned on, the first switching element is in an off state, and N is a positive integer greater than or equal to 2 and less than or equal to K.

[0010] In an exemplary embodiment, the first switching element and the fourth switching element are both N-channel metal oxide semiconductor field effect transistors.

[0011] In an exemplary embodiment, the power supply circuit further includes: a transient voltage suppressor, wherein a first terminal of the transient voltage suppressor is connected to the positive electrode of the power supply, and a second terminal of the transient voltage suppressor is grounded.

[0012] The present application also provides an electronic device, comprising: a multi-input power supply switching circuit and an electrical load, wherein the multi-input power supply switching circuit comprises K power supply circuits, wherein K is a positive integer greater than or equal to 2, and the power supply priority decreases from the first power supply circuit to the K-th power supply circuit, and the power supply circuit comprises a power supply, a switching circuit, and a control circuit; wherein, in one of the power supply circuits, the power supply supplies power to the electrical load through the switching circuit, and the control circuit is used to control the on and off of the switching circuit, and the control circuit comprises a first resistor and a second resistor, wherein the first end of the first resistor is connected to the positive electrode of the power supply, the second end of the first resistor is connected to the first end of the second resistor, and the second end of the second resistor is connected to the negative electrode of the power supply and is grounded; in the control circuits of the first power supply circuit to the K-1-th power supply circuit, a signal is drawn between the first resistor and the second resistor. an output end, for transmitting a voltage signal as a control signal to the control circuit of at least one of the power supply circuits whose power supply priority is lower than that of the power supply circuit to which it belongs through the signal output end; the control circuit of the Lth power supply circuit is further used to transmit a first control signal to the control circuits of the L+1th power supply circuit to the Kth power supply circuit respectively when the Lth power supply circuit is in a power-available state and the Lth power supply circuit meets the highest priority condition, where L is a positive integer greater than or equal to 1 and less than K, the power-available state is a state in which the power supply is turned on, and the highest priority condition is that the corresponding power supply priority is the highest power supply priority among the power supply priorities of the power supply circuits in the power-available state; the control circuits of the L+1th power supply circuit to the Kth power supply circuit are used to control the switch circuit of the power supply circuit to be in an off state in response to the first control signal.

[0013] According to the present application, a multi-input power supply switching circuit includes: K power supply circuits, wherein K is a positive integer greater than or equal to 2, and the power supply priority decreases from the first power supply circuit to the Kth power supply circuit. The power supply circuit includes a power supply, a switching circuit, and a control circuit. In one power supply circuit, the power supply supplies power to the power load through the switching circuit. The control circuit is used to control the on and off of the switching circuit. The control circuit includes a first resistor and a second resistor. The first end of the first resistor is connected to the positive electrode of the power supply, the second end of the first resistor is connected to the first end of the second resistor, and the second end of the second resistor is connected to the negative electrode of the power supply and grounded. In the control circuits of the first power supply circuit to the K-1th power supply circuit, a signal output terminal is led between the first resistor and the second resistor to transmit a voltage signal as a control signal to the control circuit of at least one power supply circuit with a lower power supply priority than the power supply circuit to which it belongs through the signal output terminal. When the power supply circuit is powered by the power supply, the first resistor and the second resistor connected in series can be used as a voltage divider circuit to sample the voltage of the power supply. The voltage obtained by the voltage divider can be transmitted as a control signal to the power supply circuit with lower priority to shut down the power supply circuit with lower priority. The control circuit of the Lth power supply circuit is also used. When the Lth power supply circuit is in a power-supply state and the Lth power supply circuit meets the highest priority condition, a first control signal is transmitted to the control circuits of the L+1th power supply circuit to the Kth power supply circuit respectively, where L is a positive integer greater than or equal to 1 and less than K, the power-supply state is a state in which the power supply is turned on, and the highest priority condition is that the corresponding power supply priority is the highest power supply priority among the power supply priorities of the power supply circuits in the power-supply state; the control circuits of the L+1th power supply circuit to the Kth power supply circuit are used to control the switch circuits of the power supply circuits to be in the off state in response to the first control signal. state, thereby improving the circuit design of the multi-input power supply switching circuit. When the power supply of the power supply circuit with the highest current priority is turned on, the first resistor and the second resistor in the control circuit of the power supply circuit can divide the power supply. The voltage obtained by the voltage division can be input as a control signal to the power supply circuit with a lower priority than the power supply circuit, so that the switch circuit of the power supply circuit with a lower priority than the power supply circuit is turned off. Therefore, it can solve the problem of insufficient reliability and safety caused by easy confusion of priorities in the multi-input power supply switching circuit in the related art, and improve the reliability and safety of the multi-input power supply switching circuit. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] In order to more clearly illustrate the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0015] Figure 1 A schematic structural diagram of an optional multi-input power supply switching circuit provided in an embodiment of the present application.

[0016] Figure 2 A schematic structural diagram of another optional multi-input power supply switching circuit provided in an embodiment of the present application.

[0017] Figure 3 A schematic structural diagram of another optional multi-input power supply switching circuit provided in an embodiment of the present application.

[0018] Figure 4 A schematic structural diagram of another optional multi-input power supply switching circuit provided in an embodiment of the present application.

[0019] Figure 5 A schematic structural diagram of another optional multi-input power supply switching circuit provided in an embodiment of the present application.

[0020] Figure 6 A schematic structural diagram of an optional electronic device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0021] The following will be combined with the accompanying drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of them. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0022] It should be noted that, in the description of this application, the terms "comprises," "includes," or any other variations thereof are intended to encompass non-exclusive inclusion, such that an article or device comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or elements inherent to such article or device. The terms "first," "second," etc., in this application are used to distinguish similar objects, and are not used to describe a particular order or sequence.

[0023] In order to enable those skilled in the art to better understand the present application, the present application is further described in detail below with reference to the accompanying drawings and specific implementation methods.

[0024] According to one aspect of an embodiment of the present application, a multi-input power supply switching circuit is provided. Figure 1 FIG. 1 is a schematic structural diagram of an optional multi-input power supply switching circuit according to an embodiment of the present application. Figure 1As shown, the circuit may include: K power supply circuits 101, where K is a positive integer greater than or equal to 2, and the power supply priority decreases from the first power supply circuit to the Kth power supply circuit. The power supply circuit includes a power supply source 1011, a switching circuit 1012 and a control circuit 1013.

[0025] The multi-input power supply switching circuit in this embodiment can be applied to the field of electronic circuit technology, and can be applied to scenarios where power is supplied by multiple power supplies.

[0026] In electronic product design, power loads may include a variety of devices, including microprocessors, memory, and sensors. These devices have varying requirements for supply voltage, current, and stability. To meet these demands, multiple power inputs are required to flexibly adapt to varying device operating conditions. In some cases, multiple power supplies are employed to improve system availability and reliability. Each power supply may have its own power priority. Multiple power supply options can be categorized as either having the same supply voltage or having different supply voltages.

[0027] When multiple input power supplies share the same supply voltage, designing a switching circuit is relatively straightforward. For example, dedicated power management components can be used. These components integrate power detection, switching logic, and protection circuitry. These components automatically identify the status of each power supply and switch power sources based on preset priorities. Another approach is to use discrete components, such as MOSFETs (metal oxide semiconductor field-effect transistors, or MOS transistors), diodes, and resistors, to build a logic switching circuit. By detecting the voltage and status of each power supply, the MOSFETs can be manually turned on and off to achieve power switching.

[0028] However, when multiple input power supplies have different supply voltages, design complexity increases significantly. In particular, when high-voltage and low-voltage power supplies coexist, connecting them directly to the same output terminal can cause the high-voltage power supply to flow into the low-voltage circuit through the parasitic body diode of the MOSFET or diode, resulting in parallel power supplies. This can not only disrupt normal circuit operation but also damage the power supply. Therefore, when designing power supply switching circuits with different supply voltages, voltage isolation and priority control must be considered to prevent high-voltage interference with low-voltage circuits while ensuring that the high-priority power supply receives power first.

[0029] The design of multi-input power switching circuit in related technology is as follows Figure 2As shown in the figure, when input power supplies 1, 2, 3, and 4 are all supplying power, the gate-source voltage of switch QX1 is equal to input power supply 1, turning on switch QX1 and lowering the gate voltage of switch Q1. The voltage of power supply 1 is then passed to the source of Q1 through the parasitic body diode of switch Q1, resulting in a negative high-voltage gate-source voltage, turning on switch Q1. Simultaneously, input power supply 1 controls the gates of switches Q2, Q3, and Q4 to a high level via diodes ZA1, ZA2, and ZA3, respectively, turning switches Q2, Q3, and Q4 off. The output voltage VOUT at the output terminal is supplied by input power supply 1 via switch Q1. When input power supply 1 has no voltage output and input power supplies 2, 3, and 4 are all powered, the gate-source voltage of switch QX2 equals input power supply 2, turning on switch QX2 and lowering the gate voltage of switch Q2. The voltage of input power supply 2 is then passed to the source of Q2 via the parasitic body diode of switch Q2, resulting in a negative high-voltage gate-source voltage, turning on switch Q2. At this point, input power supply 2 controls the gates of switches Q3 and Q4 to a high level via diodes ZB1 and ZB2, respectively, turning them off. The output is powered by input power supply 2 via switch Q2.

[0030] here, Figure 2 The diodes in the figure are backflow prevention diodes. For example, diode ZB1 prevents backflow from input power 1 to input power 2, and diode ZD1 prevents backflow from input power 1 to input power 4.

[0031] In the above technical solution, a high-priority input power supply voltage is used to control a low-priority switch unit, disconnecting the low-priority power supply circuit to achieve control of the power supply priority of multiple input power supplies. However, when the low-priority input power supply voltage is higher than the high-priority input power supply voltage, the high-voltage low-priority power supply voltage can flow to the output terminal through the parasitic body diode of the switch tube. Here, due to the internal structural characteristics of the MOS tube, a parasitic diode exists. When the voltage difference between the source and drain of the MOS tube exceeds the forward conduction voltage of the diode, the parasitic diode can conduct, forming a current path. In the multi-input power supply switching circuit, if the voltage of the low-priority power supply is higher than the voltage of the high-priority power supply, even if the high-priority power supply has started supplying power, the voltage of the low-priority power supply can flow to the output terminal through the parasitic diode, thereby supplying power in parallel with the high-priority power supply. On the one hand, the originally designed priority control logic is destroyed, and the low-priority power supply can supply power to the load unplanned. On the other hand, connecting two or more power supplies to the same load simultaneously to form parallel power supply can lead to unreasonable current distribution, mutual interference between the power supplies, and even power supply damage or circuit overheating. In addition, this technical solution uses a large number of anti-backflow diodes and the design is relatively complex.

[0032] It can be seen from this that when the input power voltage of the low power supply priority is higher than the input power voltage of the high power supply priority, the multi-input power supply switching circuit in the related art not only fails to meet the power supply priority requirements, but also causes the problem of parallel connection of the input power output, and in severe cases may cause the input power to burn out. That is, the multi-input power supply switching circuit in the related art has the problem of insufficient reliability and safety due to the easy confusion of priorities.

[0033] To address at least some of the above-mentioned technical issues, in this embodiment, an improved circuit design is proposed. This design achieves efficient switching and isolation of power supplies with different voltages through control signals and a specific circuit structure. Specifically, a multi-input power supply switching circuit is provided, comprising: K power supply circuits, wherein K is a positive integer greater than or equal to 2, and the power supply priority decreases from the first power supply circuit to the Kth power supply circuit. The power supply circuits include power supplies, switching circuits, and control circuits. In one power supply circuit, the power supply supplies power to a load via the switching circuit. The control circuit is used to control the switching circuit. The control circuit includes a first resistor and a second resistor. The first end of the first resistor is connected to the positive electrode of the power supply, the second end of the first resistor is connected to the first end of the second resistor, the second end of the second resistor is connected to the negative electrode of the power supply and is grounded; in the control circuit of the first power supply circuit to the K-1th power supply circuit, a signal output end is led out between the first resistor and the second resistor to transmit a voltage signal as a control signal to the control circuit of at least one power supply circuit with a lower power supply priority than the power supply circuit to which it belongs through the signal output end. When a power supply circuit is powered by the power supply, the first resistor and the second resistor connected in series can be used as a voltage divider circuit to sample the voltage of the power supply, and the voltage obtained by voltage division can be used as a control signal to the power supply circuit with a lower priority. The control circuit of the Lth power supply circuit is further used to transmit a first control signal to the control circuits of the L+1th power supply circuit to the Kth power supply circuit respectively when the Lth power supply circuit is in a power-available state and the Lth power supply circuit meets the highest priority condition, L is a positive integer greater than or equal to 1 and less than K, the power-available state is a state in which the power supply is turned on, and the highest priority condition is that the corresponding power supply priority is the highest power supply priority among the power supply priorities of the power supply circuits in the power-available state; the control circuits of the L+1th power supply circuit to the Kth power supply circuit are used to control, in response to the first control signal, The switching circuit of the power supply circuit to which it belongs is in an off state, thereby improving the circuit design of the multi-input power supply switching circuit. When the power supply of the power supply circuit with the highest current priority is turned on, the first resistor and the second resistor in the control circuit of the power supply circuit can divide the power supply, and the voltage obtained by the voltage division can be input as a control signal into the power supply circuit with a lower priority than the power supply circuit, so that the switching circuit of the power supply circuit with a lower priority than the power supply circuit is turned off. Therefore, the problem of insufficient reliability and safety caused by easy confusion of priorities in the multi-input power supply switching circuit in the related art can be solved, thereby improving the reliability and safety of the multi-input power supply switching circuit.

[0034] In this embodiment, the multi-input power supply switching circuit may include multiple power supply circuits, each of which includes a power supply, a switching circuit and a control circuit. Different power supplies may have different voltage levels and power output capabilities. The multi-input power supply switching circuit may be used to supply power to an electrical load, wherein, when supplying power to the electrical load, only one power supply may be used to supply power at the same time.

[0035] Optionally, the switch circuit in the power supply circuit may be located between the power supply and the power load, and may be composed of a number of electronic components. The switch circuit may change the conduction state based on the state of the control circuit, thereby determining the conduction state of the power supply path.

[0036] Optionally, the power supply circuits are sorted by priority, with the power supply priority decreasing from the first power supply circuit to the Kth power supply circuit. This means that if the first power supply circuit has power and meets the highest priority conditions, it will be used as the current power supply source, and other power supply circuits will be temporarily excluded. Similarly, if the first power supply circuit is not powered, the second power supply circuit can be used as the current power supply source, and so on.

[0037] Optionally, when the power supply of the Lth power supply circuit (where L is a positive integer greater than or equal to 1 and less than K, that is, it can be any circuit other than the circuit with the lowest priority) is in the turned-on state and the circuit meets the highest priority condition, its control circuit will not only activate its own switching circuit, but also send a control signal to all subsequent power supply circuits (that is, the L+1th to Kth power supply circuits) to make their switching circuits enter the off state, thereby preventing lower priority power supplies from supplying power when a higher priority power supply is supplying power, thereby avoiding parallel power supply between power supplies.

[0038] For example, Figure 3As shown, the power supply supplies power to the load through the switching circuit. The control circuit can sample the power supply voltage as a control signal to control the switching circuit on and off. When power supply 1 is in a power-supply state, control circuit 1 can control the second power supply circuit (including power supply 2, control circuit 2, and switching circuit 2) and the switching circuits of the Kth power supply circuit (including power supply K, control circuit K, and switching circuit K) to be in a power-off state. Similarly, when the first power supply circuit is in a power-off state, the second power supply circuit can provide power. At this time, control circuit 2 can control the third power supply circuit (including power supply 3, control circuit 3, and switching circuit 3) and the switching circuits of the Kth power supply circuit (including power supply K, control circuit K, and switching circuit K) to be in a power-off state. The power supply priority of the power supply switching circuit can be in ascending order of power supply numbers, that is, the power supply priority is from power supply 1 to power supply 2 to power supply K. The voltages of the power supplies can be the same or different.

[0039] Here, the power-supply state is a state in which the power supply is turned on, and the highest priority condition is that the corresponding power supply priority is the highest power supply priority among the power supply priorities of the power supply circuits in the power-supply state. When a power supply circuit (such as the Lth) is in the power-supply state and meets the highest priority condition at the same time, the switching circuit of the power supply circuit will be activated to allow power to flow from the power supply to the load. At the same time, the control circuit of the power supply circuit will also control the switching circuits of the power supply circuits with a priority lower than the Lth circuit (i.e., the L+1th to Kth power supply circuits) to be in the off state. This mechanism ensures that at any time, the load can only be powered by a power supply circuit with the highest priority, avoiding parallel connection between power supplies and possible electrical conflicts, and ensuring the safe and stable operation of the system.

[0040] Optionally, the control circuit includes a first resistor and a second resistor, wherein the first end of the first resistor is connected to the positive pole of the power supply, the second end of the first resistor is connected to the first end of the second resistor, and the second end of the second resistor is connected to the negative pole of the power supply and is grounded; wherein, in the control circuit from the first power supply circuit to the K-1th power supply circuit, a signal output end is led out between the first resistor and the second resistor to transmit a control signal to the control circuit of at least one power supply circuit whose power supply priority is lower than that of the power supply circuit to which it belongs through the signal output end.

[0041] In this embodiment, the control circuit may include a first resistor and a second resistor. The first end of the first resistor is connected to the positive terminal of the power supply, while the second end is connected to the first end of the second resistor. The second end of the second resistor is directly connected to the negative terminal of the power supply and is also grounded. This structure can form a voltage divider circuit that can convert the voltage of the power supply into a control signal.

[0042] Optionally, in the control circuit from the first power supply circuit to the K-1th power supply circuit, a signal output terminal can be drawn between the first resistor and the second resistor. The voltage value of this signal output terminal can be determined by the voltage divider ratio of the two resistors. It can reflect the voltage state of the corresponding power supply. When the voltage of the power supply reaches a certain threshold, this signal output terminal will generate an effective control signal (i.e., a voltage sufficient to drive subsequent circuits).

[0043] Optionally, when the power supply in the power supply circuit starts to provide voltage, the voltage divided on the second resistor can be sampled through the signal output end, and a control signal can be output to the control circuit of at least one power supply circuit whose power supply priority is lower than that of the power supply circuit to which it belongs, so as to control the switching circuit status of these power supply circuits, so that the switching circuits of all power supply circuits with lower priority than the current power supply circuit are turned off, thereby ensuring that only the power supply with the highest priority supplies power to the load.

[0044] Optionally, when the voltage of the power supply remains unchanged, the voltage dividing ratio of the voltage dividing circuit formed by the first resistor and the second resistor can be adjusted by adjusting the resistance values thereof, thereby adjusting the voltage value of the control signal.

[0045] It should be noted that the essence of the control signal can be a voltage signal, that is, it is essentially the voltage obtained by sampling and dividing the voltage output by the power supply by the sampling voltage divider circuit composed of the first resistor and the second resistor. Therefore, when the power supply of the power supply circuit is turned on, the power supply circuit will output the voltage as a control signal to control the power supply circuit with a lower priority than the power supply circuit.

[0046] Optionally, the control circuit of the Lth power supply circuit is also used to transmit a first control signal to the control circuits of the L+1th power supply circuit to the Kth power supply circuit respectively when the Lth power supply circuit is in a power-supply state and the Lth power supply circuit meets the highest priority condition; the control circuits of the L+1th power supply circuit to the Kth power supply circuit are used to control the switching circuits of the power supply circuits to which they belong to be in an off state in response to the first control signal.

[0047] That is, the first control signal transmitted by the Lth power supply circuit can be used to control the L+1th to Kth power supply circuits except the Lth power supply circuit currently supplying power to be in the off state.

[0048] For example, Figure 3 As shown, control circuit 1 will give control signals to control circuit 2 to control circuit K, control circuit 2 will give control signals to control circuit 3 to control circuit K, and the control method of control circuit 3 to control circuit K is similar.

[0049] Optionally, the first control signal may be generated by the control circuit of the Lth power supply circuit when the Lth power supply circuit is in a power-supplyable state. Once generated, the first control signal may be transmitted to the control circuits of all power supply circuits with a lower priority than L, i.e., the control circuits of the L+1th to Kth power supply circuits. The signal transmission may be achieved through a dedicated line or circuit network, or the Lth power supply circuit may be directly connected to other power supply circuits to complete the signal transmission.

[0050] Optionally, the control circuits that receive the first control signal can control the switching circuits of the power supply circuits to which they belong to enter the off state, which means that when a power supply circuit with a higher priority is started, all power supply circuits with lower priority than it will be automatically disconnected, even if their power supply voltage is higher than or equal to the power supply voltage of the Lth power supply circuit.

[0051] According to the embodiment provided by the present application, a multi-input power supply switching circuit includes: K power supply circuits, wherein K is a positive integer greater than or equal to 2, and the power supply priority decreases from the first power supply circuit to the K-th power supply circuit. The power supply circuit includes a power supply, a switching circuit and a control circuit; wherein, in one power supply circuit, the power supply supplies power to the power load through the switching circuit, and the control circuit is used to control the on and off of the switching circuit. The control circuit includes a first resistor and a second resistor, the first end of the first resistor is connected to the positive electrode of the power supply, the second end of the first resistor is connected to the first end of the second resistor, and the second end of the second resistor is connected to the negative electrode of the power supply and grounded; in the control circuits of the first power supply circuit to the K-1-th power supply circuit, a signal output terminal is led out between the first resistor and the second resistor to supply a signal to the control circuit of at least one power supply circuit whose power supply priority is lower than that of the power supply circuit to which it belongs through the signal output terminal. The control circuit of the Lth power supply circuit is further used to transmit a first control signal to the control circuits of the L+1th power supply circuit to the Kth power supply circuit respectively when the Lth power supply circuit is in a power-available state and the Lth power supply circuit meets the highest priority condition, L is a positive integer greater than or equal to 1 and less than K, the power-available state is a state in which the power supply is turned on, and the highest priority condition is that the corresponding power supply priority is the highest power supply priority among the power supply priorities of the power supply circuits in the power-available state; the control circuits of the L+1th power supply circuit to the Kth power supply circuit are used to control the switch circuits of the corresponding power supply circuits to be in an off state in response to the first control signal, which can solve the problem of insufficient reliability and safety caused by easy priority confusion in the multi-input power supply switching circuit in the related art, thereby improving the reliability and safety of the multi-input power supply switching circuit.

[0052] In an exemplary embodiment, the control circuit also includes a first switching element and a third resistor, wherein the source of the first switching element is grounded, the gate of the first switching element is connected between the first resistor and the second resistor, the drain of the first switching element is connected to the first end of the third resistor, and the second end of the third resistor is connected to the switching circuit; when the power supply circuit to which it belongs is in a power-supply state and the power supply circuit to which it belongs meets the highest priority condition, the first switching element is in an on state; the switching circuit includes a fourth resistor and a second switching element, wherein the first end of the fourth resistor is connected to the second end of the third resistor, the second end of the fourth resistor is connected to the source of the second switching element, the gate of the second switching element is connected between the third resistor and the fourth resistor, and the drain of the second switching element is connected to the first end of the first resistor; when the first switching element is in an on state, the second switching element is also in an on state.

[0053] In this embodiment, the control circuit may include a first switching element and a third resistor, which are used to control the on and off of the switching circuit, wherein the source of the first switching element is grounded, the gate is connected between the first resistor and the second resistor, and the drain is connected to the first end of the third resistor, and the second end of the third resistor is connected to the switching circuit.

[0054] Similar to the aforementioned embodiment, the connection between the first resistor and the second resistor forms a voltage divider network, whose output voltage is used to drive the first switching element. If the voltage of the power supply is high enough, there can be sufficient voltage to drive the first switching element into the on state, that is, when the power supply circuit to which it belongs is in a power-supply state and meets the highest priority condition, the first switching element can be in the on state, allowing subsequent control signal transmission.

[0055] Optionally, the third resistor serves as a signal transmission medium, one end of which is connected to the first switching element in the on state, and the other end transmits a control signal used to control the on and off of the switching circuit to the switching circuit. When the first switching element is turned on, the voltage on the third resistor can be transmitted to the switching circuit to control the state of the second switching element.

[0056] Optionally, the switching circuit may include a fourth resistor and a second switching element, wherein the first end of the fourth resistor is connected to the second end of the third resistor, and receives a control signal from the control circuit for controlling the on and off of the switching circuit; and the second end is connected to the source of the second switching element, the gate of the second switching element is connected between the third resistor and the fourth resistor, and its drain is connected to the first end of the first resistor, that is, connected to the positive pole of the power supply.

[0057] Optionally, when the first switching element in the control circuit is in the on state, the control signal for controlling the on and off of the switching circuit can be transmitted to the switching circuit through the third resistor. The signal will be further processed by the voltage divider network composed of the fourth resistor and the third resistor to ensure that there is sufficient voltage to drive the second switching element into the on state. Thus, the control signal output by the control circuit for controlling the on and off of the switching circuit can activate the switching circuit, allowing current to flow from the power supply through the second switching element to the load, thereby completing the power supply task.

[0058] Optionally, turning on the first switching element means opening the path between its source and drain. At this point, since the source of the first switching element is grounded, its drain also pulls down one end of the third resistor, effectively grounding the lower end of the third resistor. This changes the voltage distribution of the voltage divider network formed between the third and fourth resistors, while the other end of the third resistor remains connected to the power supply Vin1. The voltage divider between the third and fourth resistors creates a specific gate-source voltage across the third resistor. When this gate-source voltage reaches or exceeds the drive threshold voltage of the second switching element, the switching circuit is turned on. Consequently, when the first switching element is turned on, the second switching element is also turned on.

[0059] Through this embodiment, the control circuit and the switch circuit are linked to realize the power supply from the power supply source to the power load, thereby optimizing the circuit design and improving the reliability of the multi-input power switching circuit.

[0060] In an exemplary embodiment, in the Mth power supply circuit, the switching circuit further includes a third switching element, wherein the gate of the third switching element is connected to the gate of the second switching element, the source of the third switching element is connected to the source of the second switching element, and the drain of the third switching element is connected to the output end of the switching circuit. The third switching element is used to prevent the power supply current from flowing to the output end of the multi-input power supply switching circuit when the third switching element is in an off state. M is a positive integer greater than or equal to 2 and less than or equal to K.

[0061] In this embodiment, the switching circuit may include a third switching element, the gate, source and drain of the third switching element are respectively connected to the corresponding ports of the second switching element, forming a back-to-back connection, and its drain is connected to the output end of the entire circuit, that is, the power supply port for the electrical load.

[0062] Optionally, when the third switching element is in the off state, it can prevent the current of the corresponding power supply from flowing to the output end of the circuit. Here, when the second switching element is turned on, it is connected in parallel with the third switching element to form a current path, allowing current to flow from the power supply to the load. When the second switching element is required to be turned off, the presence of the third switching element can ensure that the current path is completely blocked.

[0063] Optionally, the third switching element can be connected in parallel with the second switching element to provide a dual protection mechanism. When the second switching element is in the off state, the third switching element can also be in the off state. Therefore, even if the second switching element may not be immediately or completely turned off due to parasitic effects, temperature changes, voltage fluctuations and other factors that may exist in the actual circuit, current can still flow from the drain to the source. The third switching element can also provide an additional current blocking layer to prevent the flow of current, thereby ensuring that the current path is truly blocked.

[0064] In this embodiment, when the control circuit sends a signal to turn on the second switching element, it will also control the third switching element through its gate connection to turn it on, thereby jointly forming a conductive path for current to flow from the power supply to the load. Conversely, when the control signal turns off the second switching element, the third switching element is also required to turn off, completely cutting off the current path to prevent high voltage backflow or parallel power supply problems at the output end.

[0065] Optionally, M is a positive integer greater than or equal to 2 and less than or equal to K, that is, for each power supply, there is a corresponding combination of the second switching element and the third switching element, which are jointly responsible for on-off control of the power supply.

[0066] For example, Figure 4As shown, one end of the power supply is connected to one end of the first resistor and the drain of the switch tube 1, the other end of the power supply is grounded, the other end of the first resistor is connected to one end of the second resistor and the gate of the switch tube 3, the other end of the second resistor is grounded, the gate of the switch tube 1 is connected to the third resistor, one end of the fourth resistor and the gate of the switch tube 2, the source of the switch tube 1 is connected to the other end of the third resistor and the source of the switch tube 2, the drain of the switch tube 2 is connected to the output end, the other end of the fourth resistor is connected to the drain of the switch tube 3, the source of the switch tube 3 is grounded, and the first resistor and the second resistor constitute a voltage divider circuit. When the power supply Vin1 is supplied, when the voltage on the second resistor reaches the driving threshold voltage of the switch tube 3, the switch tube 3 starts to turn on, driving the lower end of the third resistor to be equivalent to grounding. The first resistor and the second resistor divide the voltage passing through the body diode of the switch tube 1. The voltage across the third resistor is the gate-source voltage Vg1 of the switch tube 1 and the switch tube 2. When Vg1 reaches the driving threshold voltage of the switch tube 1 and the switch tube 2, the switch tube 1 and the switch tube 2 start to turn on, and the output end is powered by the power supply Vin1. When the power supply Vin1 is not supplied, the second resistor pulls down the control signal 1, the switch tube 3 is turned off, and then the switch tube 1 and the switch tube 2 are in the off state.

[0067] Through this embodiment, the third switching element is introduced to provide additional current path control and protection, thereby improving circuit reliability and electricity safety.

[0068] In an exemplary embodiment, the second switching element and the third switching element are both P-channel metal oxide semiconductor field effect transistors.

[0069] Here, in the P-channel metal oxide semiconductor field effect transistor (i.e., P-channel MOSFET, also known as PMOS tube), the on-state is triggered by the gate voltage relative to the source being lower than the threshold voltage (usually a negative voltage), while the off-state is achieved when the gate voltage is higher than the source voltage (usually a positive voltage), which can better isolate the high voltage power supply in the off state.

[0070] Optionally, a second switching element (e.g., a PMOS transistor Q1) is used to directly control the connection between the power supply and the output end. When the corresponding control signal for controlling the on / off of the switching circuit is a low voltage, the second switching element is turned on, allowing current to flow from the power supply to the output end; conversely, a high voltage control signal will turn off the second switching element, isolating the connection between the power supply and the output end, thereby preventing current backflow or parallel power supply problems at the output end.

[0071] In this embodiment, when the power supply is supplied, the voltage on the corresponding second resistor can reach the driving threshold voltage of the first switching element, causing the first switching element to be turned on, thereby pulling one end of the third resistor down to close to the ground potential. The voltage divider network formed by the third resistor and the fourth resistor can generate a gate-source voltage for the second switching element and the third switching element. The gate-source voltage actually refers to the voltage drop relative to the ground potential, that is, the gate-source voltage is a negative voltage relative to the source voltage of the PMOS tube. Therefore, the PMOS tube can be controlled to be turned on by this low-level signal.

[0072] According to this embodiment, by using P-channel metal oxide semiconductor field effect transistors as the second switch element and the third switch element, efficient and reliable power switching and current path control can be achieved, thereby improving the reliability of the circuit.

[0073] In an exemplary embodiment, in the Nth power supply circuit, the control circuit further includes N-1 fourth switching elements, wherein the gates of the N-1 fourth switching elements are respectively connected to the signal output ends of the control circuit from the 1st power supply circuit to the N-1th power supply circuit, the sources of the N-1 fourth switching elements are grounded, and the drains of the N-1 fourth switching elements are connected between the first resistor and the second resistor. When the control signal transmitted by the signal output end to which any fourth switching element is connected is turned on, the first switching element is in the off state, and N is a positive integer greater than or equal to 2 and less than or equal to K.

[0074] In this embodiment, except for the first power supply circuit (ie, the power supply circuit with the highest priority), the control circuits of other power supply circuits may include a switch element for receiving a control signal from a power supply circuit with a higher priority.

[0075] Optionally, in the Nth power supply circuit, the control circuit may further include N-1 fourth switching elements, wherein the gates of the N-1 fourth switching elements are respectively connected to the signal output ends of the control circuits of the 1st power supply circuit to the N-1th power supply circuit, that is, each fourth switching element in the control circuit may be assigned to receive the control signal output by the power supply circuits of the 1st power supply circuit to the N-1th power supply circuit. When any one of the power supply circuits from the 1st power supply circuit to the N-1th power supply circuit outputs a control signal for controlling the shutdown of the Nth power supply circuit, that is, when any power supply with a higher priority is supplying power, the Nth power supply circuit may be controlled to be shut down.

[0076] Optionally, the sources of N-1 fourth switching elements can be grounded, and the drains can be connected between the first resistor and the second resistor. When the control signal transmitted by the signal output terminal to which any fourth switching element is connected is turned on, it can pull down the voltage between the first resistor and the second resistor to be lower than the turn-on threshold of the first switching element, so that the first switching element is in the off state.

[0077] For example, Figure 5As shown, one end of the power supply 2 is connected to one end of the first resistor of the second power supply circuit and the drain of the switch tube 4, the other end of the power supply 2 is grounded, the other end of the first resistor of the second power supply circuit is connected to one end of the second resistor of the second power supply circuit, the gate of the switch tube 6 and the drain of the switch tube 7, the other end of the second resistor of the second power supply circuit is grounded, the gate of the switch tube 7 is connected to the control signal 1, the source of the switch tube 7 is grounded, the gate of the switch tube 4 is connected to one end of the third resistor and the fourth resistor of the second power supply circuit and the gate of the switch tube 5, the source of the switch tube 4 is connected to the other end of the first resistor of the second power supply circuit and the source of the switch tube 5, the drain of the switch tube 5 is connected to the output end, the other end of the second resistor of the second power supply circuit is connected to the drain of the switch tube 6, and the source of the switch tube 6 is grounded. Similarly, the control signal 2 can be generated and connected to the gate of the switch tube 6. One end of the power supply 3 is connected to one end of the first resistor of the third power supply circuit and the drain of the switch tube 8, and the other end of the power supply 3 is grounded. The other end of the first resistor of the third power supply circuit is connected to one end of the second resistor of the third power supply circuit, the gate of the switch tube 10, and the drains of the switch tubes 11 and 12. The other end of the second resistor of the third power supply circuit is grounded. The gate of the switch tube 11 is connected to the control signal 1, the source of the switch tube 11 is grounded, the gate of the switch tube 12 is connected to the control signal 2, the source of the switch tube 12 is grounded, the gate of the switch tube 8 is connected to one end of the third resistor and the fourth resistor of the third power supply circuit and the gate of the switch tube 9, the source of the switch tube 8 is connected to the other end of the third resistor of the third power supply circuit and the source of the switch tube 9, the drain of the switch tube 9 is connected to the output end, the other end of the fourth resistor of the third power supply circuit is connected to the drain of the switch tube 10, and the source of the switch tube 10 is grounded. Similarly, the control signal 3 can be generated and connected to the gate of the switch tube 10. When control signal 1 is high (i.e., not 0 and exceeding the driving threshold voltage of switch 7), switch 7 is turned on. This turns on switch 7, pulling the gate of switch 6 low, turning switch 6 off. The gate-source voltages of switches 4 and 5 are zero, failing to meet the on-state conditions and remaining off. Similarly, control signal 1 turns on switch 11, turning switches 8 and 9 off. If the voltage of power supply 2 or 3 is greater than that of power supply 1, the presence of switch 5 or 9 prevents the current from flowing to the output terminal, effectively preventing the high-voltage power supply from being forced to connect to the output terminal. Therefore, regardless of the power supply voltage, the higher-priority control signal will turn off the lower-priority switch circuit, effectively avoiding the problem of parallel output of power supplies with different voltages.

[0078] Similarly, when power supply Vin1 is not providing power, and power supplies Vin2 and Vin3 are both providing power, resistor R4 pulls control signal 1 low, turning off switches 3, 7, and 11, and ultimately turning off switches 1 and 2. When the voltage across voltage divider resistor R8 reaches the driving threshold voltage of switch 6, switch 6 turns on, along with PMOS switches 4 and 5, and the output is powered by power supply Vin2. At this point, control signal 2 is high, turning on switch 12 and turning off switches 8 and 9.

[0079] Optionally, when a higher priority power supply circuit resumes power supply, the voltages on the first resistor and the second resistor in the higher priority power supply circuit will rise accordingly until the conduction condition of the first switching element is met, thereby enabling the second switching element and the third switching element to be turned on, and the output end to be supplied with power by the higher priority power supply circuit. In addition, the higher priority power supply circuit may also output a control signal to the gate of the fourth switching element connected between the first resistor and the second resistor of the higher priority power supply circuit, thereby turning it on and turning off the second switching element and the third switching element of its corresponding power supply circuit, thereby interrupting the power supply circuit of the power supply circuit originally supplying power, thereby enabling the power supply of the output end to be naturally switched to the power supply of the higher priority power supply circuit.

[0080] For example, if Vin2 is currently supplying power to the output, and the higher-priority power supply Vin1 suddenly starts supplying power, the voltage across resistor R4 reaches the conduction condition for Q3, turning on Q3. This conduction causes switches Q1 and Q2 to turn on from off. Simultaneously, control signal CTR1 also turns on Q7 and Q11. Q7's conduction causes switches Q4 and Q5 to turn off from on. Switches Q8 and Q9 remain off, and power to the output naturally switches from Vin2 to Vin1.

[0081] Optionally, when the voltage of the high-priority power supply begins to gradually rise, the voltage across R4 can also gradually increase. This process is gradual, not instantaneous, so the voltage of the control signal also changes gradually. During this process, the power supply at the output terminal smoothly transitions from the low-priority power supply to the high-priority power supply. Because the voltage change throughout this process is gradual, without sudden changes, a smooth power supply transition is ensured, avoiding sudden changes and conflicts in the output terminal voltage.

[0082] Through this embodiment, the fourth switch element is used to receive the control signal of the power supply circuit with a higher priority, so the logical order of the power supply priority can be maintained, thereby improving the reliability and safety of the circuit.

[0083] In an exemplary embodiment, the first switching element and the fourth switching element are both N-channel metal oxide semiconductor field effect transistors.

[0084] Here, the N-channel metal oxide semiconductor field effect transistor (N-channel MOSFET, also known as NMOS tube) is another common type of transistor. It is turned on when the voltage of the gate relative to the source is higher than the threshold voltage. That is, when the gate voltage is higher than the threshold voltage of the NMOS tube, the conductive channel formed between the source and drain of the transistor can transmit current. It is suitable for signal amplification, switching circuits, and situations in which the current path needs to be opened under a high-level control signal in the circuit.

[0085] Optionally, the NMOS transistor may serve as the first switching element or the fourth switching element, and change its conduction state based on whether the voltage input to its gate is higher than a threshold.

[0086] According to this embodiment, by using N-channel metal oxide semiconductor field effect transistors as the first switch element and the fourth switch element, flexible and reliable control logic can be implemented, thereby improving the safety and reliability of the circuit.

[0087] In an exemplary embodiment, the power supply circuit further includes: a transient voltage suppressor, wherein a first terminal of the transient voltage suppressor is connected to the positive electrode of the power supply, and a second terminal of the transient voltage suppressor is grounded.

[0088] Here, a transient voltage suppressor (TVS) is an electronic component that can be used to protect circuits from voltage transients (i.e., voltage spikes or voltage surges). Due to its high-efficiency voltage clamping characteristics and low response time, when the voltage in the circuit exceeds the clamping voltage of the TVS, the TVS can quickly switch from a high-impedance state to a low-impedance state, releasing or consuming the excess voltage energy through its own path, thereby keeping the voltage in the circuit within a safe range.

[0089] In this embodiment, the first end of the transient voltage suppressor can be connected to the positive terminal of the power supply, while the second end is directly grounded, forming a protection path across the positive terminal of the power supply and the ground potential. Therefore, the transient voltage suppressor can monitor the voltage status of the power supply in real time and immediately intervene to provide protection when a voltage transient is detected.

[0090] Optionally, an overcurrent protection device can be added to the switching circuit, such as a current-limiting resistor or an overcurrent detection circuit. This device can be located in the power supply path between the PMOS and NMOS transistors, or in the connection line between the source of the PMOS transistor and the load. This device can trigger a protective action when the current exceeds a predetermined threshold, such as disconnecting the circuit or reducing the current, to prevent damage to the circuit due to overcurrent. This overcurrent protection helps ensure that the circuit will not suffer fatal damage even in the event of a short circuit or other fault, extending the circuit's service life and reducing maintenance costs.

[0091] Optionally, an overvoltage protection circuit or an overtemperature protection circuit can be added to the output end, which can be connected between the output end and the final electrical load to monitor the output voltage and immediately cut off the power supply once it is detected that the voltage exceeds the safe range; the overtemperature protection circuit can automatically disconnect the power supply when the circuit overheats to prevent the circuit from being damaged due to overheating, thereby ensuring that the output voltage and temperature are within the safe range, avoiding irreversible damage to the electrical equipment, and enhancing the overall stability of the circuit.

[0092] Through this embodiment, by setting the transient voltage suppressor, immediate voltage protection can be provided, thereby enhancing the robustness and safety of the circuit.

[0093] An embodiment of the present application further provides an electronic device, Figure 6 is a schematic diagram of the structure of an electronic device provided in an embodiment of the present application, such as Figure 6As shown, the electronic device includes: a multi-input power supply switching circuit 601 and an electrical load 602, the multi-input power supply switching circuit 601 includes K power supply circuits 101, wherein K is a positive integer greater than or equal to 2, and the power supply priority decreases from the first power supply circuit to the K-th power supply circuit. The power supply circuit 101 includes a power supply 1011, a switch circuit 1012 and a control circuit 1013; wherein, in one power supply circuit 101, the power supply 1011 supplies power to the electrical load 602 through the switch circuit 1012, the control circuit 1013 is used to control the on and off of the switch circuit 1012, and the control circuit 1013 includes a first resistor and a second resistor, the first end of the first resistor is connected to the positive electrode of the power supply 1011, the second end of the first resistor is connected to the first end of the second resistor, and the second end of the second resistor is connected to the negative electrode of the power supply 1011 and grounded; in the control circuit 1013 of the first power supply circuit 101 to the K-1-th power supply circuit 101, the first resistor and the second resistor are connected. A signal output terminal is led out to transmit, through the signal output terminal, a voltage signal serving as a control signal to a control circuit 1013 of at least one power supply circuit 101 having a lower power supply priority than the power supply circuit 101 to which it belongs. The control circuit 1013 of the Lth power supply circuit 101 is further configured to transmit, when the Lth power supply circuit 101 is in a power-available state and the Lth power supply circuit 101 meets a highest priority condition, a first control signal to the control circuits 1013 of the L+1th power supply circuit 101 to the Kth power supply circuit 101, respectively. L is a positive integer greater than or equal to 1 and less than K. The power-available state is a state in which the power supply source 1011 is turned on. The highest priority condition is that the corresponding power supply priority is the highest power supply priority among the power supply priorities of the power supply circuits 101 in the power-available state. The control circuits 1013 of the L+1th power supply circuit 101 to the Kth power supply circuit 101 are configured to control the switch circuits 101 of the power supply circuits 101 to be in an off state in response to the first control signal.

[0094] For the description of the features in the embodiments corresponding to the above electronic device, reference can be made to the relevant description of the embodiments corresponding to the above multi-input power supply switching circuit, which will not be described in detail here.

[0095] The above is a detailed introduction to a multi-input power supply switching circuit and electronic device provided by the present application. Specific examples are used herein to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only used to help understand the solution and core ideas of the present application. It should be pointed out that for ordinary technicians in this technical field, without departing from the principles of the present application, several improvements and modifications can be made to the present application, and these improvements and modifications also fall within the scope of protection of the claims of the present application.

Claims

1. A multi-input power supply switching circuit, characterized in that: include: K power supply circuits, wherein K is a positive integer greater than or equal to 2, and the power supply priority decreases from the first power supply circuit to the Kth power supply circuit, and the power supply circuit includes a power supply, a switching circuit, and a control circuit; wherein, In one of the power supply circuits, the power supply supplies power to the power load through the switching circuit, and the control circuit is used to control the switching circuit. The control circuit includes a first resistor and a second resistor, wherein a first end of the first resistor is connected to the positive electrode of the power supply, a second end of the first resistor is connected to the first end of the second resistor, and a second end of the second resistor is connected to the negative electrode of the power supply and is grounded. In the control circuits of the first power supply circuit to the K-1th power supply circuit, a signal output terminal is led out between the first resistor and the second resistor, so as to transmit, through the signal output terminal, a voltage signal serving as a control signal to the control circuit of at least one power supply circuit having a lower power supply priority than the power supply circuit to which it belongs; The control circuit of the Lth power supply circuit is further configured to transmit a first control signal to the control circuits of the L+1th power supply circuit to the Kth power supply circuit, respectively, when the Lth power supply circuit is in a power-available state and the Lth power supply circuit meets a highest priority condition, where L is a positive integer greater than or equal to 1 and less than K, the power-available state is a state in which the power supply is turned on, and the highest priority condition is that the corresponding power supply priority is the highest power supply priority among the power supply priorities of the power supply circuits in the power-available state; The control circuits of the L+1th power supply circuit to the Kth power supply circuit are configured to control the switch circuits of the power supply circuits to be in an off state in response to the first control signal.

2. The multi-input power supply switching circuit according to claim 1, wherein: In one of the power supply circuits, The control circuit further includes a first switching element and a third resistor, wherein the source of the first switching element is grounded, the gate of the first switching element is connected between the first resistor and the second resistor, the drain of the first switching element is connected to the first end of the third resistor, and the second end of the third resistor is connected to the switching circuit; when the power supply circuit to which it belongs is in a power supplyable state and the power supply circuit to which it belongs meets the highest priority condition, the first switching element is in a conducting state; The switching circuit includes a fourth resistor and a second switching element, wherein the first end of the fourth resistor is connected to the second end of the third resistor, the second end of the fourth resistor is connected to the source of the second switching element, the gate of the second switching element is connected between the third resistor and the fourth resistor, and the drain of the second switching element is connected to the first end of the first resistor; when the first switching element is in the on state, the second switching element is also in the on state.

3. The multi-input power supply switching circuit according to claim 2, wherein: In the Mth power supply circuit, The switching circuit further includes a third switching element, wherein a gate of the third switching element is connected to a gate of the second switching element, a source of the third switching element is connected to a source of the second switching element, and a drain of the third switching element is connected to an output end of the switching circuit. The third switching element is configured to prevent the power supply current from flowing to the output end of the multi-input power supply switching circuit when the third switching element is in an off state. M is a positive integer greater than or equal to 2 and less than or equal to K.

4. The multi-input power supply switching circuit according to claim 3, wherein: The second switching element and the third switching element are both P-channel metal oxide semiconductor field effect transistors.

5. The multi-input power supply switching circuit according to claim 2, wherein: In the Nth power supply circuit, the control circuit further includes N-1 fourth switching elements, wherein the gates of the N-1 fourth switching elements are respectively connected to the signal output ends of the control circuit from the 1st power supply circuit to the N-1th power supply circuit, the sources of the N-1 fourth switching elements are grounded, and the drains of the N-1 fourth switching elements are connected between the first resistor and the second resistor. When the control signal transmitted by the signal output end to which any fourth switching element is connected is turned on, the first switching element is in an off state, and N is a positive integer greater than or equal to 2 and less than or equal to K.

6. The multi-input power supply switching circuit according to claim 5, characterized in that: The first switching element and the fourth switching element are both N-channel metal oxide semiconductor field effect transistors.

7. The multi-input power supply switching circuit according to any one of claims 1 to 6, characterized in that: The power supply circuit further includes a transient voltage suppressor, wherein a first end of the transient voltage suppressor is connected to the positive electrode of the power supply, and a second end of the transient voltage suppressor is grounded.

8. An electronic device, characterized in that: include: A multi-input power supply switching circuit and a power load, wherein the multi-input power supply switching circuit includes K power supply circuits, wherein K is a positive integer greater than or equal to 2, and the power supply priority decreases from the first power supply circuit to the Kth power supply circuit. The power supply circuit includes a power supply source, a switching circuit, and a control circuit; wherein, In one of the power supply circuits, the power supply supplies power to the power load through the switching circuit, the control circuit is used to control the switching circuit, and the control circuit includes a first resistor and a second resistor, wherein a first end of the first resistor is connected to the positive electrode of the power supply, a second end of the first resistor is connected to the first end of the second resistor, and a second end of the second resistor is connected to the negative electrode of the power supply and grounded; In the control circuits of the first power supply circuit to the K-1th power supply circuit, a signal output terminal is led out between the first resistor and the second resistor, so as to transmit, through the signal output terminal, a voltage signal serving as a control signal to the control circuit of at least one power supply circuit having a lower power supply priority than the power supply circuit to which it belongs; The control circuit of the Lth power supply circuit is further configured to transmit a first control signal to the control circuits of the L+1th power supply circuit to the Kth power supply circuit, respectively, when the Lth power supply circuit is in a power-available state and the Lth power supply circuit meets a highest priority condition, where L is a positive integer greater than or equal to 1 and less than K, the power-available state is a state in which the power supply is turned on, and the highest priority condition is that the corresponding power supply priority is the highest power supply priority among the power supply priorities of the power supply circuits in the power-available state; The control circuits of the L+1th power supply circuit to the Kth power supply circuit are configured to control the switch circuits of the power supply circuits to be in an off state in response to the first control signal.

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