Power supply selection circuit, chip and electronic device

Abstract

The present application provides a power supply selection circuit, a chip, and an electronic device. The power supply selection circuit comprises: a plurality of voltage conversion modules, each voltage conversion module comprising a voltage conversion unit and a soft-start unit; a voltage selection module, the voltage selection module being used for selecting one of the plurality of voltage conversion modules as a target voltage conversion module to output a target voltage; and a soft-start shielding module, the soft-start shielding module being used for controlling the soft-start unit of at least one voltage conversion module.

Description

Power supply selection circuit, chip and electronic device

[0001] The present application claims priority to the Chinese patent application No. 202410803651.8, filed on June 20, 2024, and entitled "Power supply selection circuit, chip and electronic device", the whole content of which is incorporated herein by reference. TECHNICAL FIELD

[0002] The present application relates to the technical field of integrated circuits, in particular to a power supply selection circuit, a chip and an electronic device. BACKGROUND

[0003] At present, when an electronic device has one or more internal power supplies (such as a battery) and / or accesses one or more external power supplies (such as a power supply input by a TYPE-C interface), one of the power supplies needs to be selected for power supply to ensure the normal operation of the electronic device. In general, since the output voltages of the power supplies are not unified, a voltage conversion circuit is needed to convert the input voltages of the power supplies into a target voltage, for example, converting a 20V voltage input by an external TYPE-C interface into a 3.3V voltage; for another example, converting a 5V voltage provided by an internal battery module into a 3.3V voltage, so as to supply power to a corresponding circuit module (such as a single-chip microcomputer) by the 3.3V voltage.

[0004] In the related art, in order to prevent the overshoot voltage in the power-on process, a soft start circuit is usually arranged in the voltage conversion circuit, which reduces the power-on speed of the voltage conversion circuit, thereby reducing the overshoot voltage in the power-on process. However, when the electronic device is switched from being powered by one power supply to being powered by another power supply, the soft start circuit will cause the power supply switching time of the electronic device to be longer, and the long power supply switching process may cause the problem of current backflow from one power supply to another power supply and thus damage the circuit. Therefore, how to avoid the overshoot voltage in the power-on process and the current backflow problem in the power supply switching process has become the direction of efforts of the person skilled in the art. TECHNICAL PROBLEM

[0005] The embodiments of the present application provide a power supply selection circuit, a chip and an electronic device to solve the problems of overshoot voltage in the power-on process and current backflow in the power supply switching process. TECHNICAL SOLUTION

[0006] The technical solution of the present application is as follows:

[0007] In a first aspect, the embodiments of the present application provide a power supply selection circuit for selecting one of a plurality of power supplies for power supply and outputting a target voltage, the power supply selection circuit comprising:

[0008] a plurality of voltage conversion modules, each voltage conversion module comprising a voltage conversion unit and a soft start unit, the voltage conversion unit being configured to convert an output voltage of a power supply into a target voltage, and the soft start unit being configured to reduce an overshoot voltage generated by the voltage conversion unit during power-on;

[0009] a voltage selection module configured to select one of the plurality of voltage conversion modules as a target voltage conversion module, so that the target voltage conversion module outputs the target voltage;

[0010] a soft start shielding module configured to control the soft start unit of at least one voltage conversion module;

[0011] wherein, when the voltage selection module switches one of the at least one voltage conversion module as the target voltage conversion module, the soft start shielding module shields the soft start unit of the target voltage conversion module.

[0012] In a second aspect, an embodiment of the present application further provides a chip comprising the power supply selection circuit.

[0013] In a third aspect, an embodiment of the present application further provides an electronic device comprising the chip or the power supply selection circuit. Advantages

[0014] The soft start shielding module controls the soft start unit of at least one voltage conversion module, and when the voltage selection module switches one of the at least one voltage conversion module as the target voltage conversion module to output the target voltage, the soft start shielding module shields the soft start unit of the target voltage conversion module, so that the voltage conversion power supply in the target voltage conversion module bypasses the soft start unit to start quickly and output the target voltage. That is, the soft start unit is used to prevent overshoot voltage in the circuit when the voltage conversion module starts normally, and the soft start shielding module is used to shield the soft start unit of the voltage conversion module to be switched when the power supply is switched, so that the time of the power supply switching process is shortened, the overshoot voltage in the power-on process is avoided, and the current backflow problem in the power supply switching process is solved, which is finally beneficial to ensure the normal work of the power supply selection circuit.

[0015] These aspects or other aspects of the present application will be made clearer in the following description of embodiments. BRIEF DESCRIPTION OF DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed in the embodiment description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative effort.

[0017] FIG. 1 shows a power supply schematic diagram of an electronic device in the related art.

[0018] FIG. 2 shows a schematic diagram of a power supply selection circuit in embodiments of the present application.

[0019] FIG. 3 shows another schematic diagram of a power supply selection circuit in embodiments of the present application.

[0020] FIG. 4 shows a schematic diagram of a soft start shielding module and a voltage conversion module in embodiments of the present application.

[0021] FIG. 5 shows another schematic diagram of a soft start shielding module and a voltage conversion module in embodiments of the present application.

[0022] FIG. 6 shows another schematic diagram of a power supply selection circuit in embodiments of the present application.

[0023] FIG. 7 shows another schematic diagram of a power supply selection circuit in embodiments of the present application.

[0024] FIG. 8 shows another schematic diagram of a power supply selection circuit in embodiments of the present application.

[0025] FIG. 9 shows another schematic diagram of a power supply selection circuit in embodiments of the present application.

[0026] FIG. 10 shows a schematic diagram of a voltage conversion module in embodiments of the present application.

[0027] FIG. 11 shows another schematic diagram of a power supply selection circuit in embodiments of the present application.

[0028] FIG. 12 shows another schematic diagram of a power supply selection circuit in embodiments of the present application.

[0029] FIG. 13 shows another schematic diagram of a power supply selection circuit in embodiments of the present application.

[0030] FIG. 14 shows another schematic diagram of a power supply selection circuit in embodiments of the present application.

[0031] FIG. 15 shows another schematic diagram of a power supply selection circuit in embodiments of the present application.

[0032] FIG. 16 shows another schematic diagram of a power supply selection circuit in embodiments of the present application.

[0033] FIG. 17 shows another schematic diagram of a power supply selection circuit in embodiments of the present application.

[0034] Wherein, 100 is a power supply selection circuit, 10 is a voltage conversion module, 101 is a first voltage conversion module, 102 is a second voltage conversion module, 11 is a voltage conversion unit, 12 is a soft start unit, 20 is a voltage selection module, 30 is a soft start shielding module, 40 is a reset detection module, 50 is a maximum voltage selection module, 60 is a band gap reference module, 200 is a power supply, 201 is an internal power supply, 202 is an external power supply;

[0035] A target voltage Vout, a first set voltage V01, a first system control signal Sysx, a second system control signal Sysy, a system selection signal Sysz, a reset indication signal Rest, a first reference voltage VR;

[0036] A first comparator COMP1, a first inverter INV1, a first multiplexer MUX1, a second multiplexer MUX2, a second comparator COMP2, a first switch S1, a second switch S2.

[0037] Embodiments of the present application

[0038] The embodiments of the present application will be described in detail below, examples of the embodiments are shown in the accompanying drawings, wherein the same or similar notations represent the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by referring to the accompanying drawings are exemplary, only for explaining the present application, and cannot be understood as a limitation of the present application.

[0039] In order to make the person skilled in the art better understand the scheme of the present application, the technical scheme in the embodiments of the present application will be described clearly and completely below by combining the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by the person skilled in the art without creative labor are within the scope of protection of the present application.

[0040] In the embodiments of the present application, it should be noted that in this paper, relationship terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between the entities or operations.

[0041] Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0042] In the description of the embodiments of this application, the words "example" or "for example" are used to indicate exemplification, illustration, or description. Any embodiment or design described as "example" or "for example" in the embodiments of this application is not to be construed as being more preferred or having more advantages than another embodiment or design. The use of the words "example" or "for example" is intended to present relative concepts in a clear manner.

[0043] Furthermore, in the embodiments of this application, "multiple" refers to two or more. Therefore, in the embodiments of this application, "multiple" can also be understood as "at least two". "At least one" can be understood as one or more, such as one, two, or more. For example, including at least one means including one, two, or more, and is not limited to which ones are included. For example, including at least one of A, B, and C, then it could include A, B, C, A and B, A and C, B and C, or A and B and C.

[0044] It should be noted that in the embodiments of this application, "and / or" describes the relationship between associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. In addition, the character " / ", unless otherwise specified, generally indicates that the associated objects before and after it are in an "or" relationship.

[0045] It should be noted that in the embodiments of this application, "connection" can be understood as electrical connection. The connection between two electrical components can be a direct or indirect connection between the two electrical components. For example, the connection between A and B can be a direct connection between A and B, or an indirect connection between A and B through one or more other electrical components.

[0046] In the embodiments of this application, the first and second ends of the electronic components (such as resistors or capacitors) are structurally symmetrical, so their first and second ends may be structurally indistinguishable. For example, when the electronic component is a capacitor, the first and second ends of the capacitor refer to the end connected to one side of the capacitor's electrode and the other end connected to the other side of the capacitor's electrode, respectively; when the electronic component is a resistor, the first end of the resistor refers to either of its two ends, and the second end of the resistor refers to the other end of its two ends.

[0047] Currently, when the electronic device has multiple internal power supplies and / or accesses multiple external power supplies, one of the power supplies needs to be selected for power supply to ensure the normal operation of the electronic device. For example, referring to FIG. 1, FIG. 1 shows a power supply schematic diagram of an electronic device in the related art, which includes a battery module, an MCU single-chip microcomputer, a step-down / step-up circuit, a TYPE-C interface, a low-dropout linear regulator 1, a low-dropout linear regulator 2, a voltage selector, and a bandgap reference circuit.

[0048] Among them, the 20V voltage accessed by the TYPE-C interface is converted into a 40V voltage by the step-down / step-up circuit to charge the battery module, the voltage output by the battery module is used by the 5V power supply circuit after being processed by the step-down / step-up circuit, the low-dropout linear regulator 1 can convert the 5V voltage output by the battery module into a 3.3V voltage according to the 3.3V reference voltage output by the bandgap reference source, and the low-dropout linear regulator 2 can convert the 20V voltage output by the TYPE-C interface into a 3.3V voltage according to the 3.3V reference voltage output by the bandgap reference source, so as to provide a stable power supply voltage for the MCU single-chip microcomputer. When the battery module has electricity (for example, when the voltage output by the battery module is greater than or equal to 4.8V), the voltage selector selects the 3.3V voltage output by the low-dropout linear regulator 1; when the battery module has no electricity (for example, when the voltage output by the battery module is less than 4.8V), the voltage selector selects the 3.3V voltage output by the low-dropout linear regulator 2, so as to ensure the normal power supply of the electronic device.

[0049] In the related art, in order to prevent the overshoot voltage that occurs in the power-on process, the low-dropout linear regulator usually has a soft start circuit (for example, a large capacitor connected to ground) at the same time, which reduces the power-on speed of the voltage conversion circuit, thereby reducing the peak current in the power-on process. However, when switching the power supply, for example, when the voltage selector is switched from the 3.3V voltage output by the low-dropout linear regulator 2 to the 3.3V voltage output by the low-dropout linear regulator 1, the soft start circuit will cause the power supply switching time to be long, and the long power supply switching process may cause the TYPE-C interface power supply to flow back to the battery module, thereby causing the problem of circuit damage.

[0050] Therefore, the present application provides a power supply selection circuit, a chip, and an electronic device, which are described in detail below.

[0051] First, referring to FIG. 2, FIG. 2 shows a schematic diagram of a power supply selection circuit 100 in an embodiment of the present application, wherein the power supply selection circuit 100 is used to select one of multiple power supplies 200 for power supply and output a target voltage Vout, and the power supply selection circuit 100 includes a voltage conversion module 10, a voltage selection module 20, and a soft start shielding module 30.

[0052] In some embodiments of the present application, the target voltage Vout is used to power the corresponding target circuit and / or target module, which can include but is not limited to MCU single-chip microcomputer, CPU, GPU, digital signal processor, memory, graphics card, display module, speaker module, Bluetooth transceiver module, RF (radio frequency) amplifier, filter, sensor, actuator, etc. The power supply 200 can be but is not limited to a battery and / or a power supply provided by an interface, and the battery can be but is not limited to a zinc-based battery, a nickel-based battery, a lead-based battery, a lithium-based battery, a manganese dioxide series battery, or an air (oxygen) series battery, etc. The zinc-based battery such as zinc-manganese battery, zinc-silver battery, the nickel-based battery such as nickel-cadmium battery and nickel-hydrogen battery, etc., the lead-based battery such as lead-acid battery, etc., the lithium-based battery such as lithium-ion battery, lithium polymer battery, lithium iron phosphate battery, etc., the manganese dioxide series battery such as zinc-manganese battery, alkaline manganese battery, etc., the air (oxygen) series battery such as zinc-air battery, aluminum-air battery, etc.; the interface can be but is not limited to TYPE-C interface, TYPE-B interface, TYPE-A interface, Micro USB interface, Lightning interface, USB A interface, USB B interface, round interface, 30-pin charging interface, Combo socket, Dock interface, SDP interface, etc.

[0053] In some embodiments of the present application, the plurality of power supplies 200 can refer to power supplies provided by a plurality of batteries, for example, the plurality of power supplies 200 includes power supplies provided by lithium-ion batteries and power supplies provided by zinc-manganese batteries. In some embodiments of the present application, the plurality of power supplies 200 can refer to power supplies 200 provided by a plurality of interfaces, for example, the plurality of power supplies 200 includes power supplies provided by TYPE-C interfaces and power supplies provided by USB B interfaces. In some embodiments of the present application, a part of the plurality of power supplies 200 is provided by a battery, and the remaining part of the plurality of power supplies 200 is provided by an interface, for example, the plurality of power supplies 200 includes power supplies provided by lithium-ion batteries and power supplies provided by TYPE-C interfaces.

[0054] Each voltage conversion module 10 includes a voltage conversion unit 11 and a soft start unit 12, wherein the voltage conversion unit 11 is configured to convert the output voltage V1, V2 of the power supply 200 into a target voltage Vout, for example, the output voltage of the power supply 200 is 20V, and the voltage conversion module 10 can convert the 20V voltage into 3.3V; for another example, the output voltage of the power supply 200 is 5V, and the voltage conversion module 10 can convert the 5V voltage into 3.3V; the soft start unit 12 is configured to reduce the overshoot voltage generated by the voltage conversion unit 11 during power-on, for example, the voltage conversion unit 11 may

[0055] Exemplarily, the voltage conversion unit 11 can include but is not limited to a low dropout linear regulator, a BOOST boost circuit or a BUCK buck circuit, etc.; the soft start unit 12 can include but is not limited to an inductive impedance element, such as a capacitor and / or an inductor, which is arranged at the power supply 200 access end and / or control end of the voltage conversion unit 11.

[0056] The voltage selection module 20 is configured to select one of the plurality of voltage conversion modules 10 as a target voltage conversion module 10, so that the target voltage conversion module 10 outputs the target voltage Vout. In some embodiments of the present application, the voltage selection module 20 can select one of the plurality of voltage conversion modules 10 as the target voltage conversion module 10 based on the output voltage size of a certain power supply 200 to output the target voltage Vout, for example, in the initial state, the voltage selection module 20 selects the voltage conversion module 10 connected to the 5V output of the battery as the target voltage conversion module 10 to output the target voltage Vout 3.3V, and when the output voltage of the battery is less than 5V, the voltage selection module 20 selects the voltage conversion module 10 connected to the 20V voltage (for example, the 20V voltage output by the TYPE-C interface) as the target voltage conversion module 10 to output the target voltage Vout 3.3V.

[0057] In some embodiments of the present application, the voltage selection module 20 can select one of the plurality of voltage conversion modules 10 as the target voltage conversion module 10 to output the target voltage Vout in response to a system instruction output by a control unit (e.g., an MCU). For example, when the TYPE-C interface accesses the power supply 200, the control unit can output a system instruction to the voltage selection module 20, so that the voltage selection module 20 selects the voltage conversion module 10 accessing the 20V voltage as the target voltage conversion module 10 to output the target voltage Vout. For another example, when the control unit detects that the battery temperature is too high, the control unit can output a system instruction to the voltage selection module 20, so that the voltage selection module 20 selects the voltage conversion module 10 accessing the 20V voltage as the target voltage conversion module 10 to output the target voltage Vout of 3.3V, thereby avoiding the phenomenon that the battery continues to discharge when the temperature is too high, resulting in the reduction of the battery capacity or the service life.

[0058] The soft start shielding module 30 is configured to control the soft start unit 12 of at least one voltage conversion module 10. For example, when the voltage selection module 20 switches another voltage conversion module 10 as the target voltage conversion module 10 to output the target voltage Vout, the soft start shielding module 30 can shield the soft start unit 12 of the target voltage conversion module 10. For another example, when none of the voltage conversion modules 10 outputs the target voltage Vout, the voltage selection module 20 selects the target voltage conversion module 10 to normally start power-up, the soft start shielding module 30 can unshield the soft start unit 12 of the target voltage conversion module 10, so that the target voltage conversion module 10 normally powers up and prevents the overshoot voltage phenomenon occurring in the power-up process.

[0059] In some embodiments of the present application, the soft start shielding module 30 can control the soft start unit 12 of only part of the voltage conversion modules 10. For example, referring to FIG. 2, the soft start shielding module 30 is electrically connected to the soft start unit 12 of one of the voltage conversion modules 10, and when the voltage selection module 20 switches the voltage conversion module 10 to output the target voltage Vout, the soft start shielding module 30 can shield the soft start unit 12 of the voltage conversion module 10. In some other embodiments of the present application, the soft start shielding module 30 can control the soft start unit 12 of all the voltage conversion modules 10. For example, referring to FIG. 3, which shows another schematic diagram of the power supply selection circuit 100 in the embodiments of the present application, the soft start shielding module 30 is electrically connected to the soft start unit 12 of all the voltage conversion modules 10, and when the voltage selection module 20 switches any of the voltage conversion modules 10 to output the target voltage Vout, the soft start shielding module 30 can shield the soft start unit 12 of the switched voltage conversion module 10.

[0060] As an example, with the low voltage linear voltage stabilizer as an example, referring to FIG. 4, FIG. 4 shows a schematic diagram of the soft start shielding module 30 and the voltage conversion module 10 in the embodiment of the present application, wherein the voltage conversion unit 11 comprises an operational amplifier OP, a switching transistor M1, series-connected voltage dividing resistors R3 and R4, and a low-pass filter composed of a filter resistor R5 and a filter capacitor C4. The first end of the switching transistor M1 is connected to the output voltage V1 / V2 of a power supply 200, the second end of the switching transistor M1 is connected to the voltage dividing resistor R3, the non-inverting input terminal of the operational amplifier OP is used to connect to a reference voltage VBG, the inverting input terminal of the operational amplifier OP is connected between the voltage dividing resistors R3 and R4 to receive a feedback voltage VFB, and the output terminal of the operational amplifier OP is connected to the control terminal of the switching transistor M1, so that the operational amplifier OP, the switching transistor M1, and the voltage dividing resistor R3 form a negative feedback loop, and finally ensure the stability of the output target voltage Vout between the switching transistor M1 and the resistor R3.

[0061] The soft start unit 12 comprises a first resistor R1, a first capacitor C1, a second resistor R2, and a second capacitor C2. After the reference voltage VBG is input, the first capacitor C1 and the second capacitor C2 will be charged first, thereby reducing the overshoot voltage generated by the voltage conversion unit 11 during the power-on process. The soft start shielding module 30 comprises a first switch S1 and a second switch S2. The first switch S1 controls whether the non-inverting input terminal of the operational amplifier OP is conducted through the soft start unit 12 to control whether the non-inverting input terminal of the operational amplifier OP is connected to the reference voltage VBG through the soft start unit 12. The second switch S2 controls whether the non-inverting input terminal of the operational amplifier OP is directly connected to the reference voltage VBG.

[0062] When the first switch S1 is closed and the second switch S2 is open, the reference voltage VBG is first charged to the first capacitor C1 and the second capacitor C2. After the charging is completed, the non-inverting input terminal of the operational amplifier OP receives the reference voltage VBG to control the conduction voltage of the switching transistor M1. This process corresponds to the normal start-up process of the voltage conversion module 10, which is beneficial to avoid the overshoot voltage in the power-on process of the voltage conversion module 10. When the voltage selection module 20 switches another voltage conversion module 10 as the target voltage conversion module 10 to output the target voltage Vout, the first switch S1 is open and the second switch S2 is closed at this time. The soft start unit 12 of the target voltage conversion module 10 is shielded, so that the non-inverting input terminal of the operational amplifier can directly receive the reference voltage VBG and quickly complete the conduction control process of the switching transistor M1.

[0063] It can be understood that Fig. 4 is only an example of the embodiment of the present application, and the implementation of the soft start shielding module 30 is not limited to this. For example, referring to Fig. 5, Fig. 5 shows another schematic diagram of the soft start shielding module 30 and the voltage conversion module 10 in the embodiment of the present application. A third switch S3 can be further arranged to control whether the first capacitor C1 and the second capacitor C2 are grounded, so that the soft start unit 12 is shielded or normally works.

[0064] In the embodiment of the present application, the soft start shielding module 30 is used to control the soft start unit 12 of at least one voltage conversion module 10. When the voltage selection module 20 switches one of the at least one voltage conversion module 10 as a target voltage conversion module 10 to output a target voltage Vout, the soft start shielding module 30 can shield the soft start unit 12 of the target voltage conversion module 10, so that the voltage conversion power supply 200 in the target voltage conversion module 10 bypasses the soft start unit 12 and quickly starts and outputs the target voltage Vout. That is, the soft start unit 12 is used to prevent the overvoltage of the circuit when the voltage conversion module 10 normally starts, and the soft start shielding module 30 is used to shield the soft start unit 12 of the voltage conversion module 10 to be switched when the power supply 200 is switched, so that the time of the power supply 200 switching process is shortened, the overvoltage of the power-on process is avoided, and the current backflow problem of the power supply 200 switching process is solved, which is finally beneficial to ensure the normal work of the power supply selection circuit 100.

[0065] In some embodiments of the present application, referring to Fig. 6, Fig. 6 shows another schematic diagram of the power supply selection circuit 100 in the embodiment of the present application. The plurality of power supplies 200 includes at least one internal power supply 201 and at least one external power supply 202, and the plurality of voltage conversion modules 10 includes at least one first voltage conversion module 101 and at least one second voltage conversion module 102. The first voltage conversion module 101 is used to convert a first output voltage Vsys of the internal power supply 201 into a target voltage Vout, and the second voltage conversion module 102 is used to convert a second output voltage Vbus of the external power supply 202 into the target voltage Vout.

[0066] It should be noted that the internal power supply 201 refers to the power supply provided by the internal battery of the electronic device, and the external power supply 202 refers to the power supply accessed through the interface (for example, TYPE-C interface) of the electronic device. Therefore, the first voltage conversion module 101 can convert the voltage of the battery into the target voltage Vout, and the second voltage conversion module 102 can convert the voltage accessed through the interface into the target voltage Vout. Under the control of the voltage selection module 20, the internal power supply 201 and the external power supply 202 can be coordinately controlled to facilitate the normal work of the electronic device.

[0067] In some embodiments of the present application, the soft start shielding module 30 is configured to control the soft start unit 12 of the first voltage conversion module 101. For example, referring to FIG. 6, when the power supply selection voltage includes only one first voltage conversion module 101 and one second voltage conversion module 102, the soft start shielding module 30 is connected to the soft start unit 12 of the first voltage conversion module 101 only. When the voltage selection module 20 switches from outputting the target voltage Vout from the second voltage conversion module 102 to outputting the target voltage Vout from the first voltage conversion module 101, the soft start shielding module 30 shields the soft start unit 12 of the first voltage conversion module 101, so that the first voltage conversion module 101 quickly outputs the target voltage Vout, thereby quickly completing the switching process of the voltage conversion module 10.

[0068] For another example, referring to FIG. 7, FIG. 7 shows another schematic diagram of the power supply selection circuit 100 in an embodiment of the present application. The power supply selection voltage includes a plurality of first voltage conversion modules 101 and a plurality of second voltage conversion modules 102. The soft start shielding module 30 is connected to the soft start unit 12 of the plurality of first voltage conversion modules 101 only. When the voltage selection module 20 switches from outputting the target voltage Vout from one first voltage conversion module 101 to outputting the target voltage Vout from another first voltage conversion module 101, the soft start shielding module 30 shields the soft start unit 12 of the another first voltage conversion module 101, so that the another first voltage conversion module 101 quickly outputs the target voltage Vout, thereby quickly completing the switching process of the voltage conversion module 10.

[0069] It should be noted that, since the power source of the first voltage conversion module 101 is derived from the battery, and the power source of the second voltage conversion module 102 is derived from the interface, the voltage selection module 20 selects the first voltage conversion module 101 to output the target voltage Vout usually in the case that the battery is powered, and the voltage selection module 20 selects the second voltage conversion module 102 to output the target voltage Vout usually in the case that the battery is not powered. Therefore, in general, the current backflow phenomenon exists only when the voltage selection module 20 switches to the first voltage conversion module 101 to output the target voltage Vout (i.e., when the battery is powered), and does not exist when the voltage selection module 20 switches to the second voltage conversion module 102 to output the target voltage Vout (i.e., when the battery is not powered). That is, in the above embodiment, the soft start shielding module 30 is configured to control the soft start unit 12 of the first voltage conversion module 101 only, which can effectively solve the current backflow problem in the switching process of the power supply 200.

[0070] It can be understood that the power supply 200 and the voltage conversion module 10 in the above-mentioned FIG. 6 and FIG. 7 are one-to-one corresponding, that is, one voltage conversion module 10 only converts the output voltage of one power supply 200 and outputs the target voltage Vout, but is not limited thereto. For example, referring to FIG. 8, FIG. 8 shows another schematic diagram of the power supply selection circuit 100 in the embodiment of the present application. The same first voltage conversion module 101 can convert the output voltage of multiple internal power supplies 201 into the target voltage Vout, and the same second voltage conversion module 102 can convert the output voltage of multiple external power supplies 202 into the target voltage Vout.

[0071] In some embodiments of the present application, for example, for the embodiment in which the voltage selection module 20 can select one of the multiple voltage conversion modules 10 to output the target voltage Vout based on the output voltage of the power supply 200, when the first output voltage Vsys of the internal power supply 201 is less than the first set voltage V01 (for example, 5V), the voltage selection module 20 selects the second voltage conversion module 102 to output the target voltage Vout; when the first output voltage Vsys of the internal power supply 201 is greater than or equal to the first set voltage V01, the voltage selection module 20 selects the first voltage conversion module 101 to output the target voltage Vout. That is, the voltage selection module 20 can switch the second voltage conversion module 102 corresponding to the external power supply 202 to output the target voltage Vout when the internal power supply 201 is out of power, and switch the first voltage conversion module 101 corresponding to the internal power supply 201 to output the target voltage Vout when the internal power supply 201 is powered, thereby avoiding the phenomenon of sudden power failure caused by the sudden removal of the external power supply 202 (for example, the power line connected to the TYPE interface is suddenly unplugged).

[0072] In some embodiments of the present application, referring to FIG. 9, FIG. 9 shows another schematic diagram of the power supply selection circuit 100 in the embodiment of the present application, wherein the voltage selection module 20 includes a first comparator COMP1; the first input end of the first comparator COMP1 is used to access the first set voltage V01, the second input end of the first comparator COMP1 is used to access the first output voltage Vsys of the internal power supply 201, the output end of the first comparator COMP1 is connected with the first voltage conversion module 101, and the output end of the first comparator COMP1 is connected with the second voltage conversion module 102.

[0073] As an implementation, when the first output voltage Vsys output by the internal power supply 201 is greater than the first set voltage V01, the first comparator COMP1 outputs a high level signal, which can control the first voltage conversion module 101 to output the target voltage Vout and control the second voltage conversion module 102 to stop outputting the target voltage Vout; on the contrary, when the first output voltage Vsys output by the internal power supply 201 is less than the first set voltage V01, the first comparator COMP1 outputs a low level signal, which can control the first voltage conversion module 101 to stop outputting the target voltage Vout and control the second voltage conversion module 102 to output the target voltage Vout.

[0074] As an exemplary embodiment of the voltage selection module 20 controlling the voltage conversion module 10 to output the target voltage Vout, referring to FIG. 10, FIG. 10 shows a schematic diagram of the voltage conversion module 10 in the embodiment of the present application, wherein the voltage conversion unit 11 further comprises a selection transistor M2, the control end of the selection transistor M2 is connected with the output end of the first comparator COMP1, when the first comparator COMP1 outputs a low level signal, the selection transistor M2 is turned on so as to make the voltage conversion unit 11 output the target voltage Vout; on the contrary, when the first comparator COMP1 outputs a high level signal, the selection transistor M2 is turned off so as to make the voltage conversion unit 11 stop outputting the target voltage Vout.

[0075] For example, when the selection transistors M2 of the first voltage conversion module 101 and the second voltage conversion module 102 are both PMOS tubes, the signal output by the first comparator COMP1 can be inverted by an inverter and then input to the control end of the selection transistor M2 of the first voltage conversion module 101, and the signal output by the first comparator COMP1 is directly input to the control end of the selection transistor M2 of the second voltage conversion module 102, so as to make the voltage selection module 20 select the second voltage conversion module 102 to output the target voltage Vout when the first output voltage Vsys of the internal power supply 201 is less than the first set voltage V01 (for example, 5V); and make the voltage selection module 20 select the first voltage conversion module 101 to output the target voltage Vout when the first output voltage Vsys of the internal power supply 201 is greater than or equal to the first set voltage V01.

[0076] It can be understood that the above embodiments are exemplarily described by taking the selection transistor M2 of the first voltage conversion module 101 and the second voltage conversion module 102 as PMOS tubes, but are not limited thereto. For example, when the selection transistor M2 of the first voltage conversion module 101 and the second voltage conversion module 102 are NMOS tubes, the signal output by the first comparator COMP1 can be directly input to the control end of the selection transistor M2 of the first voltage conversion module 101, and the signal output by the first comparator COMP1 can be input to the control end of the selection transistor M2 of the second voltage conversion module 102 after being inverted by the inverter; or, the voltage selection module 20 can also control whether the voltage conversion module 10 outputs the target voltage Vout by other manners, for example, setting whether the voltage conversion unit 11 receives the reference voltage VBG or setting whether the voltage conversion unit 11 outputs the target voltage Vout.

[0077] In some embodiments of the present application, for example, for the embodiment in which the voltage selection module 20 can select one of the plurality of voltage conversion modules 10 as the target voltage conversion module 10 to output the target voltage Vout in response to the instruction output by the control unit, referring to FIG. 11, FIG. 11 shows another schematic diagram of the power supply selection circuit 100 in the embodiments of the present application, wherein the voltage selection module 20 further comprises a first inverter INV1, a first multiplexer MUX1 and a second multiplexer MUX2; the input end of the first inverter INV1 is connected with the output end of the first comparator COMP1, and the output end of the first inverter INV1 is connected with the first input end of the first multiplexer MUX1; the second input end of the first multiplexer MUX1 is used to access the first system control signal Sysx, the first input end of the second multiplexer MUX2 is connected with the output end of the first comparator COMP1, and the second input end of the second multiplexer MUX2 is used to access the second system control signal Sysy; the output end of the first multiplexer MUX1 is connected with the first voltage conversion module 101, the output end of the second multiplexer MUX2 is connected with the second voltage conversion module 102, and the control ends of the first multiplexer MUX1 and the second multiplexer MUX2 are used to access the system selection signal Sysz.

[0078] It should be noted that the first multiplexer MUX1 can output one of the signal output by the first inverter INV1 and the first system control signal Sysx, and the second multiplexer MUX2 can output one of the signal output by the first comparator COMP1 and the second system control signal Sysy. For example, taking the selection transistor M2 of the first voltage conversion module 101 and the second voltage conversion module 102 as PMOS tubes as an example, when the signal output by the first comparator COMP1 is a high-level signal, the signal output by the first inverter INV1 is a low-level signal, and the system selection signal Sysz controls the first multiplexer MUX1 to select the signal output by the first comparator COMP1 after being inverted by the first inverter INV1, and the system selection signal Sysz controls the second multiplexer MUX2 to select the signal output by the first comparator COMP1, then at this time the selection transistor M2 of the first voltage conversion module 101 will receive a low-level signal, and the selection transistor M2 of the second voltage conversion module 102 will receive a high-level signal, so at this time the voltage selection module 20 selects the first voltage conversion module 101 to output the target voltage Vout based on the control of the first comparator COMP1.

[0079] When the first system control signal Sysx is a high-level signal, the second system control signal Sysy is a low-level signal, and the system selection signal Sysz controls the first multiplexer MUX1 to select the first system control signal Sysx, and the system selection signal Sysz controls the second multiplexer MUX2 to select the second system control signal Sysy, then at this time the selection transistor M2 of the first voltage conversion module 101 will receive a high-level signal, and the selection transistor M2 of the second voltage conversion module 102 will receive a low-level signal, so at this time the voltage selection module 20 selects the second voltage conversion module 102 to output the target voltage Vout based on the system instruction.

[0080] It can be seen that the voltage selection module 20 in the above embodiment can select one of the plurality of voltage conversion modules 10 as the target voltage conversion module 10 to output the target voltage Vout in response to the instruction output by the control unit, and can select one of the plurality of voltage conversion modules 10 to output the target voltage Vout based on the output voltage of the power supply 200, which is advantageous to realize flexible selection of the voltage conversion module 10.

[0081] In some embodiments of the present application, when the first voltage conversion module 101 outputs the target voltage Vout, the voltage selection module 20 stops outputting the enable signals for controlling the first voltage conversion module 101 and the second voltage conversion module 102 in response to a system instruction (e.g., a system instruction issued by the MCU); when the first output voltage Vsys of the internal power supply 201 is less than the first set voltage V01, the voltage selection module 20 re-outputs the enable signals for controlling the first voltage conversion module 101 and the second voltage conversion module 102 in response to a system instruction (e.g., a system instruction issued by the MCU).

[0082] It should be noted that, since the first set voltage V01 and the first output voltage Vsys fluctuate, the first comparator COMP1 may cause the output signal thereof to alternate between high and low levels due to voltage fluctuation, which is not conducive to the output of a stable target voltage Vout by the power supply selection circuit 100. In the above embodiment, when the first voltage conversion module 101 outputs the target voltage Vout, the system instruction controls the voltage selection module 20 to stop outputting the enable signals for controlling the first voltage conversion module 101 and the second voltage conversion module 102, so that the first voltage conversion module 101 and the second voltage conversion module 102 are no longer controlled by the output voltage of the first comparator COMP1, thereby avoiding the instability of the power supply selection circuit 100 caused by the change of the high and low levels of the output of the first comparator COMP1.

[0083] Meanwhile, when the first output voltage Vsys of the internal power supply 201 is less than the first set voltage V01, the soft start shielding module 30 controls the voltage selection module 20 to restart, so that the soft start module re-outputs the enable signals for controlling the first voltage conversion module 101 and the second voltage conversion module 102, thereby ensuring the normal operation of the voltage selection module 20. In addition, since the voltage selection module 20 stops working when the first voltage conversion module 101 outputs the target voltage Vout, and the voltage selection module 20 restarts when the first output voltage Vsys of the internal power supply 201 is less than the first set voltage V01, the voltage selection module 20 is not always in the working state during the operation of the power supply selection circuit 100, which is conducive to reducing the power consumption of the power supply selection circuit 100.

[0084] In some embodiments of the present application, referring to FIG. 12, FIG. 12 shows another schematic diagram of the power supply selection circuit 100 in the embodiments of the present application, wherein the input end of the soft start shielding module 30 is connected with the output end of the plurality of voltage conversion modules 10, and the output end of the soft start shielding module 30 is connected with the soft start unit 12 of at least one voltage conversion module 10, so that the soft start shielding module 30 controls the soft start unit 12 of at least one voltage conversion module 10 according to the target voltage Vout. For example, when the voltage selection module 20 is switched from the target voltage Vout output by the second voltage conversion module 102 to the target voltage Vout output by the first voltage conversion module 101, the soft start shielding module 30 can shield the soft start unit 12 of the first voltage conversion module 101 according to the target voltage Vout, so as to quickly complete the switching process from the target voltage Vout output by the second voltage conversion module 102 to the target voltage Vout output by the first voltage conversion module 101.

[0085] As an example, referring to FIG. 13, FIG. 13 shows another schematic diagram of the power supply selection circuit 100 in the embodiments of the present application, wherein the soft start shielding module 30 comprises a second comparator COMP2, at least one first switch S1 and at least one second switch S2; the first input end of the second comparator COMP2 is connected with the first reference voltage VR, the second input end of the second comparator COMP2 is connected with the output end of each voltage conversion unit 11; one end of the first switch S1 is connected with the output end of the soft start unit 12, the other end is connected with the input end of the voltage conversion unit 11, and the control end of the first switch S1 is connected with the output end of the second comparator COMP2; one end of the second switch S2 is connected with the input end of the soft start unit 12, the other end is connected with the input end of the voltage conversion unit 11, and the control end of the second switch S2 is connected with the output end of the second comparator COMP2.

[0086] For example, taking the first switch S1 as a PMOS tube and the second switch S2 as an NMOS tube as an example, when the voltage selection module 20 is switched from the target voltage Vout output by the second voltage conversion module 102 to the target voltage Vout output by the first voltage conversion module 101, the target voltage Vout has not fallen to high level at this time, so the second comparator COMP2 outputs a high level signal, and then the second comparator COMP2 can control the first switch S1 to be open and the second switch S2 to be closed, at this time, the voltage conversion unit of the first voltage conversion module 101 is directly connected with the reference voltage VBG without passing through the soft start unit 12 to connect with the reference voltage VBG, which is equivalent to shielding the soft start unit 12 of the first voltage conversion module 101, so that the voltage conversion unit 11 of the first voltage conversion module 101 quickly outputs the target voltage Vout, and the power supply 200 switching process is quickly completed.

[0087] When neither the first voltage conversion module 101 nor the second voltage conversion module 102 is working, and the voltage selection module 20 selects the first voltage conversion module 101 to normally start up and output the target voltage Vout, the target voltage Vout is low at this time, and thus the second comparator COMP2 outputs a low-level signal, and the second comparator COMP2 can control the first switch S1 to be closed and the second switch S2 to be opened. At this time, the voltage conversion unit 11 is connected to the reference voltage VBG through the soft start unit 12, so that the soft start unit 12 can prevent the overshoot voltage phenomenon in the power-up process of the first voltage conversion module 101.

[0088] It can be understood that the implementation of the soft start shielding module 30 is not limited to this, for example, referring to FIG. 14, which shows another schematic diagram of the power supply selection circuit 100 in the embodiment of the present application. The soft start shielding module 30 can also receive a system instruction issued by a control unit (such as an MCU) and control whether to shield the soft start unit 12 of the corresponding voltage conversion module 10.

[0089] In some embodiments of the present application, referring to FIG. 15, which shows another schematic diagram of the power supply selection circuit 100 in the embodiment of the present application, the power supply selection circuit 100 further includes a reset detection module 40. The reset detection module 40 is configured to detect the output voltage of the at least one power supply 200 and / or the internal voltage of the at least one voltage conversion module 10, so as to output a reset indication signal Rest after the output voltage of the at least one power supply 200 and / or the internal voltage of the at least one voltage conversion module 10 is powered down.

[0090] It should be noted that when the power supply selection circuit 100 is connected to only one power supply 200 (such as the internal power supply 201), if the connected power supply 200 is out of power, due to the existence of the large off-chip capacitor of the voltage conversion module 10, the reference voltage VBG may drop while the target voltage Vout is still high, which can easily lead to the phenomenon that the target voltage Vout is detected with a delay and the system (such as an MCU) can not be reset in time. In the above-mentioned embodiments, the reset detection module 40 can detect the output voltage of the power supply 200 and / or the internal voltage of the voltage conversion module 10. For example, the reset detection module 40 can detect the first output voltage Vsys of the internal power supply 201, and the reset detection module 40 can detect the output voltage of the internal charge pump of the second voltage conversion module 102. Therefore, the reset detection module 40 can quickly output a reset signal after the output voltage of the power supply 200 and / or the internal voltage of the voltage conversion module 10 is powered down, thereby avoiding the phenomenon that the target voltage Vout is detected with a delay and the system can not be reset.

[0091] Exemplarily, the reset detection module 40 can include an analog comparator or a digital circuit such as an analog-to-digital converter to realize the judgment or measurement of the output voltage of the power supply 200 and / or the internal voltage of the voltage conversion module 10.

[0092] It can be understood that the reset indication signal Rest output by the reset detection module 40 is taken as the reset signal of the system in the above embodiment, and in some possible embodiments, the output signal of the second comparator COMP2 in FIG. 13 can also be taken as the reset signal of the system, and in some other possible embodiments, the reset indication signal Rest output by the reset detection module 40 and the output signal of the second comparator COMP2 can also be taken as the reset signal, for example, the reset indication signal Rest and the output signal of the second comparator COMP2 are input into a gate circuit (for example, an AND gate, an OR gate, etc.), and the signal output by the gate circuit is taken as the reset signal of the system.

[0093] In some embodiments of the present application, referring to FIG. 16, FIG. 16 shows another schematic diagram of the power supply selection circuit 100 in the embodiments of the present application, the power supply selection circuit 100 further includes a maximum voltage selection module 50 and a bandgap reference module 60, the maximum voltage selection module 50 can select the one with the maximum voltage among the plurality of power supplies 200 to input into the bandgap reference module 60, so that the bandgap reference module 60 can output a reference voltage VBG according to the one with the maximum voltage among the plurality of power supplies 200, so as to facilitate the voltage conversion module 10 to output a target voltage Vout according to the output voltage of the corresponding power supply 200 and the reference voltage VBG.

[0094] Exemplarily, the maximum voltage selection module 50 can include but is not limited to a maximum voltage selection circuit composed of diodes or a maximum voltage selection circuit composed of a comparator and a switch; the bandgap reference module 60 can include but is not limited to a bandgap reference circuit of a current mirror type or a bandgap reference circuit of an operational amplifier type.

[0095] It can be understood that the implementation of the power supply selection circuit 100 to provide the reference voltage VBG for the voltage conversion module 10 is not limited to this, for example, referring to FIG. 17, FIG. 17 shows another schematic diagram of the power supply selection circuit 100 in the embodiments of the present application, the power supply selection circuit 100 can also be provided with a plurality of bandgap reference modules 60 to facilitate the provision of the reference voltage VBG for each voltage conversion module 10.

[0096] The embodiment of the present application further provides a chip, which comprises the power supply selection circuit 100 described above. The chip (IC) is also called a chip, which can be but is not limited to a SOC (System on Chip) chip, a SIP (system in package) chip. Since the chip of the present application comprises the power supply selection circuit 100 of the above-described embodiment, it has all the beneficial effects of the power supply selection circuit 100 in the above-described embodiment, which will not be repeated here.

[0097] The embodiment of the present application further provides an electronic device, which comprises a device main body and a chip as described above arranged in the device main body. The electronic device can be but is not limited to a body weight scale, a body fat scale, a nutrition scale, an infrared electronic thermometer, a pulse oximeter, a human body composition analyzer, a mobile power supply 200, a wireless charger, a fast charger, a vehicle charger, an adapter, a display, a USB (Universal Serial Bus) docking station, a touch pen, a true wireless earphone, a car central control screen, a car, a smart wearable device, a mobile terminal, a smart home device. The smart wearable device includes but is not limited to a smart watch, a smart bracelet, a cervical vertebra massage instrument. The mobile terminal includes but is not limited to a smart phone, a notebook computer, a tablet computer, a POS (point of sales terminal) machine. The smart home device includes but is not limited to a smart socket, a smart rice cooker, a smart sweeper, a smart lamp.

[0098] The above is only a preferred embodiment of the present application, and does not limit the present application in any form. Although the present application has been disclosed as the above-described preferred embodiment, it is not intended to limit the present application. Any person skilled in the art can make some changes or modifications to the above-described disclosed technical content to obtain equivalent embodiments with equivalent changes, without departing from the scope of the technical solution of the present application. Any modification, change and modification of the above-described embodiment according to the technical essence of the present application, which does not depart from the technical solution of the present application, is still within the scope of the technical solution of the present application.

Claims

1. A power supply selection circuit, the power supply selection circuit being used to select one of a plurality of power supplies to supply power and output a target voltage, the power supply selection circuit comprising: Multiple voltage conversion modules are provided, each including a voltage conversion unit and a soft-start unit. The voltage conversion unit is used to convert the output voltage of the power supply into the target voltage, and the soft-start unit is used to reduce the overshoot voltage generated by the voltage conversion unit during power-on. A voltage selection module is provided, which is used to select one of the plurality of voltage conversion modules as a target voltage conversion module so that the target voltage conversion module outputs the target voltage. A soft-start shielding module, wherein the soft-start shielding module is used to control at least one soft-start unit of the voltage conversion module; When the voltage selection module switches one of the at least one voltage conversion modules as the target voltage conversion module, the soft-start shielding module shields the soft-start unit of the target voltage conversion module.

2. The power supply selection circuit as described in claim 1, characterized in that, The plurality of power supplies includes at least one internal power supply and at least one external power supply, and the plurality of voltage conversion modules includes at least one first voltage conversion module and at least one second voltage conversion module; The first voltage conversion module is used to convert the first output voltage of the internal power supply into the target voltage, and the second voltage conversion module is used to convert the second output voltage of the external power supply into the target voltage.

3. The power supply selection circuit as described in claim 2, characterized in that, The soft-start shielding module is used to control the soft-start unit of the first voltage conversion module; When the voltage selection module switches from outputting the target voltage from the second voltage conversion module to outputting the target voltage from the first voltage conversion module, the soft-start shielding module shields the soft-start unit of the first voltage conversion module; or When the voltage selection module switches from outputting the target voltage from one first voltage conversion module to outputting the target voltage from another first voltage conversion module, the soft-start shielding module shields the soft-start unit of the other first voltage conversion module.

4. The power supply selection circuit as described in claim 2, characterized in that, When the first output voltage of the internal power supply is less than the first set voltage, the voltage selection module selects the second voltage conversion module to output the target voltage; When the first output voltage of the internal power supply is greater than or equal to the first set voltage, the voltage selection module selects the first voltage conversion module to output the target voltage.

5. The power supply selection circuit as described in claim 2, characterized in that, The voltage selection module includes a first comparator; The first input terminal of the first comparator is used to connect to a first set voltage, the second input terminal of the first comparator is used to connect to the first output voltage of the internal power supply, the output terminal of the first comparator is connected to the first voltage conversion module, and the output terminal of the first comparator is connected to the second voltage conversion module.

6. The power supply selection circuit as described in claim 5, characterized in that, The voltage selection module further includes a first inverter, a first multiplexer, and a second multiplexer; The input terminal of the first inverter is connected to the output terminal of the first comparator, and the output terminal of the first inverter is connected to the first input terminal of the first multiplexer. The second input terminal of the first multiplexer is used to receive the first system control signal, the first input terminal of the second multiplexer is connected to the output terminal of the first comparator, and the second input terminal of the second multiplexer is used to receive the second system control signal. The output of the first multiplexer is connected to the first voltage conversion module, the output of the second multiplexer is connected to the second voltage conversion module, and the control terminals of the first multiplexer and the second multiplexer are used to receive system selection signals.

7. The power supply selection circuit as described in claim 2, characterized in that, When the first voltage conversion module outputs the target voltage, the voltage selection module stops outputting the enable signal controlling the first voltage conversion module and the second voltage conversion module in response to the system command; When the first output voltage of the internal power supply is less than the first set voltage, the voltage selection module responds to the system command by re-outputting the enable signal controlling the first voltage conversion module and the second voltage conversion module.

8. The power supply selection circuit as described in claim 1, characterized in that, The input terminal of the soft-start shielding module is connected to the output terminals of the multiple voltage conversion modules; The output terminal of the soft-start shielding module is connected to the soft-start unit of at least one of the voltage conversion modules, so that the soft-start shielding module controls the soft-start unit of at least one of the voltage conversion modules according to the target voltage.

9. The power supply selection circuit as described in claim 8, characterized in that, The soft-start shielding module includes a second comparator, at least one first switch, and at least one second switch; The first input terminal of the second comparator is connected to the first reference voltage, and the second input terminal of the second comparator is connected to the output terminal of each of the voltage conversion units; One end of the first switch is connected to the output terminal of the soft-start unit, and the other end is connected to the input terminal of the voltage conversion unit. The control terminal of the first switch is connected to the output terminal of the second comparator. One end of the second switch is connected to the input terminal of the soft-start unit, and the other end is connected to the input terminal of the voltage conversion unit. The control terminal of the second switch is connected to the output terminal of the second comparator.

10. The power supply selection circuit as described in any one of claims 1-9, characterized in that, The power supply selection circuit also includes a reset detection module; The reset detection module is used to detect the output voltage of at least one of the power supplies and / or the internal voltage of at least one of the voltage conversion modules, so as to output a reset indication signal after the output voltage of at least one of the power supplies and / or the internal voltage of at least one of the voltage conversion modules is de-energized.

11. The power supply selection circuit as described in any one of claims 1-9, characterized in that, The power supply selection circuit also includes a maximum voltage selection module and a bandgap reference module; The maximum voltage selection module is used to select the power supply with the highest voltage among the multiple power supplies and input it into the bandgap reference module. The bandgap reference module is used to output a reference voltage based on the largest voltage among the multiple power supplies, and the voltage conversion module outputs the target voltage based on the output voltage of the corresponding power supply and the reference voltage.

12. A chip comprising a power supply selection circuit as described in any one of claims 1 to 11.

13. An electronic device comprising the chip as claimed in claim 12.

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