Power supply selection circuits, chips and electronic equipment

Abstract

The present application provides a power supply selection circuit, chip, and electronic device. The power supply selection circuit includes: multiple voltage conversion modules, each of which includes a voltage conversion unit and a soft start unit; a voltage selection module, which is used to select one of the multiple voltage conversion modules as the target voltage conversion module to output the target voltage; and a soft start shielding module, which is used to control the soft start unit of at least one voltage conversion module. The present application utilizes the soft start unit to prevent overshoot voltage in the circuit during normal startup of the voltage conversion module, and utilizes the soft start shielding module to shield the soft start unit of the switched voltage conversion module during power switching, thereby shortening the power switching process, not only avoiding overshoot voltage during the power-on process, but also solving the current backflow problem during the power switching process, ultimately ensuring the normal operation of the power supply selection circuit.

Description

Technical Field

[0001] The present application relates to the field of integrated circuit technology, and in particular to a power supply selection circuit, chip, and electronic equipment. Background Art

[0002] Currently, when an electronic device has one or more internal power sources (such as batteries) and / or is connected to one or more external power sources (such as power input via a TYPE-C interface), it is necessary to select one of the power sources to provide power to ensure the normal operation of the electronic device. Under normal circumstances, because the output voltages of each power source are not uniform, it is necessary to use a voltage conversion circuit to convert the input voltage of each power source to the target voltage. For example, the 20V voltage input from the external TYPE-C interface is converted to 3.3V; for example, the 5V voltage provided by the internal battery module is converted to 3.3V so that the corresponding circuit module (such as a microcontroller) can be powered by the 3.3V voltage.

[0003] In the related art, to prevent overshoot voltage during the power-up process, a voltage conversion circuit is typically equipped with a soft-start circuit. This circuit slows down the power-up speed of the voltage conversion circuit, thereby reducing overshoot voltage during the power-up process. However, when an electronic device switches from one power source to another, the soft-start circuit will cause the power switching time of the electronic device to be prolonged. This prolonged power switching process may cause current from one power source to flow back into the other power source, thereby damaging the circuit. Therefore, how to prevent overshoot voltage during the power-up process and current backflow during the power switching process has become a focus of research in this field. Summary of the Invention

[0004] In view of the above problems, embodiments of the present application provide a power supply selection circuit, a chip, and an electronic device to solve the above technical problems.

[0005] In a first aspect, an embodiment of the present application provides a power supply selection circuit, which is configured to select one of multiple power supplies to supply power and output a target voltage. The power supply selection circuit includes:

[0006] Multiple voltage conversion modules, each voltage conversion module includes 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 a target voltage, and the soft start unit is used to reduce the overshoot voltage generated by the voltage conversion unit during the power-on process;

[0007] a voltage selection module, the voltage selection module being 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 a target voltage;

[0008] A soft start shielding module, the soft start shielding module is used to control the soft start unit of at least one voltage conversion module;

[0009] When the voltage selection module switches one of the at least one voltage conversion module to serve as the target voltage conversion module, the soft start shielding module shields the soft start unit of the target voltage conversion module.

[0010] In a second aspect, an embodiment of the present application further provides a chip comprising the above-mentioned power supply selection circuit.

[0011] In a third aspect, an embodiment of the present application further provides an electronic device comprising the above-mentioned chip or power supply selection circuit.

[0012] The present application controls the soft start unit of at least one voltage conversion module through a soft start shielding module. When the voltage selection module switches one of the at least one voltage conversion module to output the target voltage as the target voltage conversion module, the soft start shielding module can shield the soft start unit of the target voltage conversion module, thereby allowing the voltage conversion power supply in the target voltage conversion module to bypass the soft start unit and quickly start and output the target voltage. In other words, the present application uses the soft start unit to prevent overshoot voltage in the circuit when the voltage conversion module starts normally, and uses the soft start shielding module to shield the soft start unit of the switched voltage conversion module when the power supply is switched, thereby shortening the power supply switching process, not only avoiding overshoot voltage during the power-on process, but also solving the current backflow problem during the power supply switching process, ultimately helping to ensure the normal operation of the power supply selection circuit.

[0013] These and other aspects of the present application will become more readily apparent from the description of the following embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[0015] Figure 1 A power supply schematic diagram of an electronic device in the related art is shown.

[0016] Figure 2 A schematic diagram of a power supply selection circuit in an embodiment of the present application is shown.

[0017] Figure 3 Another schematic diagram of the power supply selection circuit in an embodiment of the present application is shown.

[0018] Figure 4A schematic diagram of the soft start shielding module and the voltage conversion module in an embodiment of the present application is shown.

[0019] Figure 5 Another schematic diagram of the soft start shielding module and the voltage conversion module in the embodiment of the present application is shown.

[0020] Figure 6 Another schematic diagram of the power supply selection circuit in an embodiment of the present application is shown.

[0021] Figure 7 Another schematic diagram of the power supply selection circuit in an embodiment of the present application is shown.

[0022] Figure 8 Another schematic diagram of the power supply selection circuit in an embodiment of the present application is shown.

[0023] Figure 9 Another schematic diagram of the power supply selection circuit in an embodiment of the present application is shown.

[0024] Figure 10 A schematic diagram of a voltage conversion module in an embodiment of the present application is shown.

[0025] Figure 11 Another schematic diagram of the power supply selection circuit in an embodiment of the present application is shown.

[0026] Figure 12 Another schematic diagram of the power supply selection circuit in an embodiment of the present application is shown.

[0027] Figure 13 Another schematic diagram of the power supply selection circuit in an embodiment of the present application is shown.

[0028] Figure 14 Another schematic diagram of the power supply selection circuit in an embodiment of the present application is shown.

[0029] Figure 15 Another schematic diagram of the power supply selection circuit in an embodiment of the present application is shown.

[0030] Figure 16 Another schematic diagram of the power supply selection circuit in an embodiment of the present application is shown.

[0031] Figure 17 Another schematic diagram of the power supply selection circuit in an embodiment of the present application is shown.

[0032] Among them, 100 power supply selection circuit, 10 voltage conversion module, 101 first voltage conversion module, 102 second voltage conversion module, 11 voltage conversion unit, 12 soft start unit, 20 voltage selection module, 30 soft start shield module, 40 reset detection module, 50 maximum voltage selection module, 60 bandgap reference module, 200 power supply, 201 internal power supply, 202 external power supply;

[0033] Target voltage Vout, first set voltage V01, first system control signal Sysx, second system control signal Sysy, system selection signal Sysz, reset indication signal Rest, first reference voltage VR;

[0034] A first comparator COMP1, a first inverter INV1, a first multiplexer MUX1, a second multiplexer MUX2, a second comparator COMP2, a first switch S1, and a second switch S2. DETAILED DESCRIPTION

[0035] The embodiments of the present application are described in detail below. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present application and are not to be construed as limiting the present application.

[0036] In order to enable those skilled in the art to better understand the solutions of the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with 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 of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without making creative efforts are within the scope of protection of this application.

[0037] In the embodiments of the present application, it should be noted that, in this document, relational terms such as first and second, etc., are merely used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations.

[0038] Moreover, the terms "comprises," "comprising," or any other variations thereof are intended to encompass non-exclusive inclusion, such that a process, method, article, or apparatus that includes a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not preclude the presence of additional identical elements in the process, method, article, or apparatus that includes the element.

[0039] In the description of the embodiments of this application, words such as "example" or "for example" are used to indicate an example, illustration, or description. Any embodiment or design described as "for example" or "for example" in the embodiments of this application is not to be construed as being preferred or having more advantages than another embodiment or design. The use of words such as "example" or "for example" is intended to clearly present relative concepts.

[0040] In addition, in the embodiments of the present application, "plurality" refers to two or more. In view of this, in the embodiments of the present application, "plurality" can also be understood as "at least two". "At least one" can be understood as one or more, for example, one, two, or more. For example, "including at least one" means including one, two, or more, and does not limit which ones are included. For example, "including at least one of A, B, and C" means including A, B, C, A and B, A and C, B and C, or A, B, and C.

[0041] It should be noted that in the embodiments of the present application, "and / or" describes the association relationship between associated objects, indicating that three relationships can exist. For example, A and / or B can represent three situations: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / ", unless otherwise specified, generally indicates that the associated objects are in an "or" relationship.

[0042] It should be noted that in the embodiments of the present application, "connection" can be understood as electrical connection, and 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 either a direct connection between A and B or an indirect connection between A and B through one or more other electrical components.

[0043] The first and second ends of the electronic components (such as resistors or capacitors) used in the embodiments of this application are structurally symmetrical, so the first and second ends can be structurally indistinguishable. For example, when the electronic component is a capacitor, the first and second ends of the capacitor refer to one end connected to the plate on one side of the capacitor and the other end connected to the plate on the other side of the capacitor, respectively; when the electronic component is a resistor, the first end of the resistor refers to either end of the resistor, and the second end of the resistor refers to the other end of the resistor.

[0044] Currently, when an electronic device has multiple internal power supplies and / or is connected to multiple external power supplies, it is necessary to select one of the power supplies to power the electronic device to ensure normal operation. Figure 1 , Figure 1A power supply schematic diagram of an electronic device in the related art is shown, which includes a battery module, an MCU microcontroller, a buck / boost 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.

[0045] The 20V voltage input from the Type-C interface is converted to 40V by the buck / boost circuit to charge the battery module. The 5V output from the battery module after the buck / boost process is used by the power delivery (PD) system. Low-dropout linear regulator 1 converts the 5V output from the battery module to 3.3V based on the 3.3V reference voltage output by the bandgap reference source. Low-dropout linear regulator 2 converts the 20V output from the Type-C interface to 3.3V based on the 3.3V reference voltage output by the bandgap reference source, thereby providing a stable power supply voltage for the MCU. When the battery module is charged (for example, when the output voltage of the battery module is greater than or equal to 4.8V), the voltage selector selects low-voltage linear regulator 1 to output 3.3V. When the battery module is discharged (for example, when the output voltage of the battery module is less than 4.8V), the voltage selector selects low-voltage linear regulator 2 to output 3.3V to ensure normal power supply to the electronic device.

[0046] In the related art, to prevent overshoot voltage during power-on, a low-voltage dropout linear regulator (LDO) is typically equipped with a soft-start circuit (e.g., a large capacitor connected to ground). The soft-start circuit reduces the power-on speed of the voltage conversion circuit, thereby reducing the spike current during power-on. However, when switching power, for example, when the voltage selector switches from the 3.3V output of LDO 2 to the 3.3V output of LDO 1, the soft-start circuit will cause the power switching time to be longer. This long power switching process may cause the TYPE-C interface power to flow back into the battery module, thereby damaging the circuit.

[0047] To this end, the present application provides a power supply selection circuit, a chip, and an electronic device, which are described in detail below.

[0048] First, see Figure 2 , Figure 2 A schematic diagram of a power supply selection circuit 100 in an embodiment of the present application is shown, wherein the power supply selection circuit 100 is used to select one of multiple power supplies 200 to supply power and output a target voltage Vout. The power supply selection circuit 100 includes a voltage conversion module 10, a voltage selection module 20 and a soft start shielding module 30.

[0049] Specifically, the target voltage Vout is used to power the corresponding target circuit and / or target module. The target circuit and / or module may include but is not limited to an MCU, a CPU, a GPU, a digital signal processor, a memory, a graphics card, a display module, a speaker module, a Bluetooth transceiver module, an RF (radio frequency) amplifier, a filter, a sensor, an actuator, etc. The power supply 200 may be, but is not limited to, a power source provided by a battery and / or an interface. The battery may 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. Zinc-based batteries include zinc-manganese batteries and zinc-silver batteries, nickel-based batteries include nickel-cadmium batteries and nickel-metal hydride batteries, lead-based batteries include lead-acid batteries, etc. Lithium-based batteries include lithium-ion batteries, lithium polymer batteries, lithium iron phosphate batteries, etc. Manganese dioxide series batteries include zinc-manganese batteries and alkaline manganese batteries, etc. Air (oxygen) series batteries include zinc-air batteries and aluminum-air batteries, etc. The interface may be, but is not limited to, a TYPE-C interface, a TYPE-B interface, a TYPE-A interface, a Micro USB interface, a Lightning interface, a USB type A interface, a USB type B interface, a circular interface, a 30-pin charging interface, a Combo socket, a Dock interface, an SDP interface, etc.

[0050] In some embodiments of the present application, the multiple power sources 200 may refer to power sources provided by multiple batteries, for example, the multiple power sources 200 include power sources provided by lithium-ion batteries and power sources provided by zinc-manganese batteries. In some embodiments of the present application, the multiple power sources 200 may refer to power sources 200 provided by multiple interfaces, for example, the multiple power sources 200 include power sources provided by a TYPE-C interface and power sources provided by a USB Type-B interface. In some embodiments of the present application, a portion of the power sources 200 in the multiple power sources 200 is provided by batteries, and the remaining power 200 is provided by interfaces, for example, the multiple power sources 200 include power sources provided by lithium-ion batteries and power sources provided by a TYPE-C interface.

[0051] Each voltage conversion module 10 includes a voltage conversion unit 11 and a soft start unit 12, wherein the voltage conversion unit 11 is used to convert the output voltages V1 and V2 of the power supply 200 into a target voltage Vout. For example, if the output voltage of a power supply 200 is 20V, the voltage conversion module 10 can convert the 20V voltage into 3.3V; for another example, if the output voltage of a power supply 200 is 5V, the voltage conversion module 10 can convert the 5V voltage into 3.3V; the soft start unit 12 is used to reduce the overshoot voltage generated by the voltage conversion unit 11 during the power-on process. For example, the voltage conversion unit 11 may generate an overshoot voltage exceeding 3.3V (for example, 5V) during the power-on process. After the soft start unit 12 is set, the voltage generated by the voltage conversion unit 11 during the power-on process will be less than 3.3V, thereby avoiding the phenomenon of circuit burning or interference with digital circuits during the power-on process.

[0052] Exemplarily, the voltage conversion unit 11 may include but is not limited to a low voltage difference linear regulator, a BOOST boost circuit or a BUCK step-down circuit, etc.; the soft start unit 12 may include but is not limited to an inductive impedance element, such as a capacitor and / or an inductor, arranged at the power supply 200 access end and / or the control end of the voltage conversion unit 11.

[0053] The voltage selection module 20 is used to select one of the multiple voltage conversion modules 10 as the 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 multiple voltage conversion modules 10 as the target voltage conversion module 10 to output the target voltage Vout based on the output voltage of a certain power supply 200. For example, in the initial state, the voltage selection module 20 selects the voltage conversion module 10 connected to the 5V voltage output of the battery as the target voltage conversion module 10 to output the target voltage Vout of 3.3V. 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 of 3.3V.

[0054] In some embodiments of the present application, the voltage selection module 20 can select one of the multiple 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 is connected to the power supply 200, the control unit can output a system instruction to the voltage selection module 20, causing the voltage selection module 20 to select the voltage conversion module 10 connected to a 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, causing the voltage selection module 20 to select the voltage conversion module 10 connected to a 20V voltage as the target voltage conversion module 10 to output a target voltage Vout of 3.3V, thereby preventing the battery from continuing to discharge when the temperature is too high, resulting in a reduction in battery capacity or life.

[0055] The soft start shielding module 30 is used 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; and when no voltage conversion module 10 outputs the target voltage Vout and the voltage selection module 20 selects the target voltage conversion module 10 to start and power on normally, the soft start shielding module 30 can release the shielding effect on the soft start unit 12 of the target voltage conversion module 10, so that the target voltage conversion module 10 can be powered on normally and prevent the overshoot voltage phenomenon that occurs during the power-on process.

[0056] In some embodiments of the present application, the soft start shielding module 30 may only control the soft start units 12 of some voltage conversion modules 10, for example, see Figure 2 The soft start shielding module 30 is electrically connected to the soft start unit 12 of one of the voltage conversion modules 10. 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 units 12 of all voltage conversion modules 10. For example, see Figure 3 , Figure 3 Another schematic diagram of the power supply selection circuit 100 in an embodiment of the present application is shown. The soft start shielding module 30 is electrically connected to the soft start units 12 of all voltage conversion modules 10. When the voltage selection module 20 switches any 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 switched voltage conversion module 10.

[0057] As an example, the voltage conversion unit 11 includes a low voltage linear regulator. Figure 4 , Figure 4 A schematic diagram of the soft start shielding module 30 and the voltage conversion module 10 in an embodiment of the present application is shown, wherein the voltage conversion unit 11 includes an operational amplifier OP, a switching transistor M1, a voltage divider resistor R3 and a voltage divider resistor R4 connected in series, 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, and the second end of the switching transistor M1 is connected to the voltage divider resistor R3. The non-inverting input end of the operational amplifier OP is used to connect to the reference voltage VBG, and the inverting input end of the operational amplifier OP is connected between the voltage divider resistor R3 and the voltage divider resistor R4 to receive the feedback voltage VFB. The output end of the operational amplifier OP is connected to the control end of the switching transistor M1, so that the operational amplifier OP, the switching transistor M1, and the voltage divider resistor R3 form a negative feedback loop, ultimately ensuring the stability of the target voltage Vout output between the switching transistor M1 and the resistor R3.

[0058] The soft-start unit 12 includes a first resistor R1, a first capacitor C1, a second resistor R2, and a second capacitor C2. Upon input of the reference voltage VBG, the first capacitor C1 and the second capacitor C2 are first charged, thereby reducing the overshoot voltage generated during the power-up process of the voltage conversion unit 11. The soft-start shielding module 30 includes a first switch S1 and a second switch S2. The first switch S1 controls whether the non-inverting input of the operational amplifier OP is connected to the soft-start unit 12, thereby controlling whether the non-inverting input 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 of the operational amplifier OP is directly connected to the reference voltage VBG.

[0059] When the first switch S1 is closed and the second switch S2 is open, the reference voltage VBG first charges 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, thereby controlling the on-state voltage of the switching transistor M1. This process corresponds to the normal startup and power-on process of the voltage conversion module 10, which helps to avoid overshoot voltage during 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. The soft start unit 12 of the target voltage conversion module 10 is shielded. Therefore, the non-inverting input terminal of the operational amplifier can directly receive the reference voltage VBG and quickly complete the on-state control process of the switching transistor M1.

[0060] Understandably, Figure 4This is only an exemplary embodiment of the present application, and the implementation of the soft start shielding module 30 is not limited thereto. For example, see Figure 5 , Figure 5 Another schematic diagram of the soft start shielding module 30 and the voltage conversion module 10 in an embodiment of the present application is shown. A third switch S3 can also be set to control whether the first capacitor C1 and the second capacitor C2 are grounded, so that the soft start unit 12 is shielded or works normally.

[0061] In an embodiment of the present application, the present application controls the soft start unit 12 of at least one voltage conversion module 10 through a soft start shielding module 30. When the voltage selection module 20 switches one of the at least one voltage conversion modules 10 to serve 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, thereby allowing the voltage conversion power supply 200 in the target voltage conversion module 10 to quickly start and output the target voltage Vout by bypassing the soft start unit 12. In other words, the present application utilizes the soft start unit 12 to prevent overshoot voltage in the circuit during normal startup of the voltage conversion module 10, and utilizes the soft start shielding module 30 to shield the soft start unit 12 of the switched voltage conversion module 10 during power supply 200 switching. This shortens the switching time of the power supply 200, not only avoiding overshoot voltage during the power-on process, but also solving the current backflow problem during the power supply 200 switching process, ultimately facilitating the normal operation of the power supply selection circuit 100.

[0062] In some embodiments of the present application, see Figure 6 , Figure 6 Another schematic diagram of the power supply selection circuit 100 in an embodiment of the present application is shown, wherein the multiple power supplies 200 include at least one internal power supply 201 and at least one external power supply 202, and the multiple voltage conversion modules 10 include 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 the first output voltage Vsys of the internal power supply 201 into the target voltage Vout, and the second voltage conversion module 102 is used to convert the second output voltage Vbus of the external power supply 202 into the target voltage Vout.

[0063] It should be noted that the internal power supply 201 refers to the power provided by the internal battery of the electronic device, and the external power supply 202 refers to the power supply connected through the electronic device interface (such as the TYPE-C interface). Therefore, the first voltage conversion module 101 can convert the battery voltage into the target voltage Vout, and the second voltage conversion module 102 can convert the voltage connected to the interface into the target voltage Vout. Under the control of the voltage selection module 20, coordinated control of the internal power supply 201 and the external power supply 202 can be achieved to facilitate the normal operation of the electronic device.

[0064] In some embodiments of the present application, the soft start shielding module 30 is used to control the soft start unit 12 of the first voltage conversion module 101, for example, see Figure 6 The power supply selection voltage includes only a first voltage conversion module 101 and a second voltage conversion module 102. The soft start shielding module 30 is only connected to the soft start unit 12 of the first voltage conversion module 101. 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.

[0065] For example, see Figure 7 , Figure 7 Another schematic diagram of the power supply selection circuit 100 in an embodiment of the present application is shown. The power supply selection voltage only includes multiple first voltage conversion modules 101 and multiple second voltage conversion modules 102. The soft start shielding module 30 is only connected to the soft start units 12 of the multiple first voltage conversion modules 101. 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 other first voltage conversion module 101, so that the other first voltage conversion module 101 quickly outputs the target voltage Vout, thereby quickly completing the switching process of the voltage conversion module 10.

[0066] It should be noted that, since the power supply of the first voltage conversion module 101 is derived from the battery, and the power supply 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 when the battery is usually charged, and the voltage selection module 20 selects the second voltage conversion module 102 to output the target voltage Vout when the battery is usually discharged. Therefore, under normal circumstances, the current backflow phenomenon only exists 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 charged). When the voltage selection module 20 switches to the second voltage conversion module 102 to output the target voltage Vout, the current backflow phenomenon does not exist because the battery is discharged. In other words, in the above embodiment, only the soft start shielding module 30 controls the soft start unit 12 of the first voltage conversion module 101, which can also effectively solve the current backflow problem during the switching process of the power supply 200.

[0067] Understandably, the above Figure 6 as well as Figure 7 The power supply 200 and the voltage conversion module 10 are in one-to-one correspondence, that is, a voltage conversion module 10 only converts the output voltage of a power supply 200 and outputs the target voltage Vout, but is not limited to this. For example, see Figure 8 , Figure 8 Another schematic diagram of the power supply selection circuit 100 in an embodiment of the present application is shown. The same first voltage conversion module 101 can convert the output voltages of multiple internal power supplies 201 into a target voltage Vout, and the same second voltage conversion module 102 can convert the output voltages of multiple external power supplies 202 into a target voltage Vout.

[0068] In some embodiments of the present application, for example, in an embodiment where 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 (e.g., 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. In other words, when the internal power supply 201 is out of power, 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, and when the internal power supply 201 is powered, the voltage selection module 20 can switch the first voltage conversion module 101 corresponding to the internal power supply 201 to output the target voltage Vout, thereby preventing a sudden power outage caused by the sudden removal of the external power supply 202 (e.g., the power cord connected to the TYPE interface is suddenly unplugged).

[0069] In some embodiments of the present application, see Figure 9 , Figure 9 Another schematic diagram of the power supply selection circuit 100 in an embodiment of the present application is shown, wherein the voltage selection module 20 includes a first comparator COMP1; the first input end of the first comparator COMP1 is used to connect to the first set voltage V01, the second input end of the first comparator COMP1 is used to connect to the first output voltage Vsys of the internal power supply 201, the output end of the first comparator COMP1 is connected to the first voltage conversion module 101, and the output end of the first comparator COMP1 is connected to the second voltage conversion module 102.

[0070] Specifically, 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; conversely, 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.

[0071] As an exemplary embodiment of a voltage selection module 20 controlling a voltage conversion module 10 to output a target voltage Vout, refer to Figure 10 , Figure 10 A schematic diagram of the voltage conversion module 10 in an embodiment of the present application is shown, wherein the voltage conversion unit 11 further includes a selection transistor M2, the control end of the selection transistor M2 is connected to 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 that the voltage conversion unit 11 outputs the target voltage Vout; conversely, when the first comparator COMP1 outputs a high-level signal, the selection transistor M2 is turned off, so that the voltage conversion unit 11 stops outputting the target voltage Vout.

[0072] For example, when both the selection transistors M2 of the first voltage conversion module 101 and the second voltage conversion module 102 are PMOS transistors, the signal output by the first comparator COMP1 can be inverted by an inverter and then input into the control end of the selection transistor M2 of the first voltage conversion module 101. The signal output by the first comparator COMP1 is directly input into the control end of the selection transistor M2 of the second voltage conversion module 102. This allows the voltage selection module 20 to 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 (e.g., 5V); and 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.

[0073] It can be understood that the above embodiment is illustrative using the example that the selection transistors M2 of the first voltage conversion module 101 and the second voltage conversion module 102 are both PMOS tubes, but is not limited to this. For example, when the selection transistors M2 of the first voltage conversion module 101 and the second voltage conversion module 102 are both NMOS tubes, the signal output by the first comparator COMP1 can be directly input into 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 inverted by the inverter and then input into the control end of the selection transistor M2 of the second voltage conversion module 102; alternatively, the voltage selection module 20 can also control whether the voltage conversion module 10 outputs the target voltage Vout in other ways, such as setting whether the switch controls the voltage conversion unit 11 to receive the reference voltage VBG or setting whether the switch controls the voltage conversion unit 11 to output the target voltage Vout.

[0074] In some embodiments of the present application, for example, the voltage selection module 20 can select one of the multiple 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, see Figure 11 , Figure 11Another schematic diagram of the power supply selection circuit 100 in an embodiment of the present application is shown, wherein the voltage selection module 20 further includes a first inverter INV1, a first multiplexer MUX1 and a second multiplexer MUX2; the input end of the first inverter INV1 is connected to the output end of the first comparator COMP1, and the output end of the first inverter INV1 is connected to 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 to 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 to the first voltage conversion module 101, the output end of the second multiplexer MUX2 is connected to 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.

[0075] It should be noted that the first multiplexer MUX1 can select one of the signal output by the first inverter INV1 and the first system control signal Sysx for output, and the second multiplexer MUX2 can select one of the signal output by the first comparator COMP1 and the second system control signal Sysy for output. For example, taking the example that the selection transistors M2 of the first voltage conversion module 101 and the second voltage conversion module 102 are both PMOS tubes, 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. Therefore, 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.

[0076] 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 for output, and the system selection signal Sysz controls the second multiplexer MUX2 to select the second system control signal Sysy for output, 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. Therefore, the voltage selection module 20 selects the second voltage conversion module 102 to output the target voltage Vout based on the system instruction.

[0077] It can be seen that the voltage selection module 20 in the above embodiment can select one of the multiple 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, or can select one of the multiple voltage conversion modules 10 to output the target voltage Vout based on the output voltage size of the power supply 200, which is conducive to the flexible selection of the voltage conversion module 10.

[0078] 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 signal 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 an 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 signal 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 an MCU).

[0079] It should be noted that due to fluctuations in the first set voltage V01 and the first output voltage Vsys, the output signal of the first comparator COMP1 may alternate between high and low levels due to voltage fluctuations, which is detrimental to the stable output of the 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 controlling the first voltage conversion module 101 and the second voltage conversion module 102. At this time, 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 high and low level fluctuations of the output terminal of the first comparator COMP1.

[0080] At the same time, 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, causing the soft start module to re-output the enable signal 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. Furthermore, because the voltage selection module 20 stops operating when the first voltage conversion module 101 outputs the target voltage Vout, and 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 operation during the operation of the power supply selection circuit 100, thereby facilitating reduced power consumption of the power supply selection circuit 100.

[0081] In some embodiments of the present application, see Figure 12 , Figure 12 Another schematic diagram of a power supply selection circuit 100 according to an embodiment of the present application is shown, in which the input end of the soft start shielding module 30 is connected to the output ends of multiple voltage conversion modules 10, and the output end of the soft start shielding module 30 is connected to 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 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 can shield the soft start unit 12 of the first voltage conversion module 101 according to the target voltage Vout, thereby quickly completing the switching process 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.

[0082] As an example, see Figure 13 , Figure 13 Another schematic diagram of the power supply selection circuit 100 in an embodiment of the present application is shown, wherein the soft start shielding module 30 includes 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 to the first reference voltage VR, and the second input end of the second comparator COMP2 is connected to the output end of each voltage conversion unit 11; one end of the first switch S1 is connected to the output end of the soft start unit 12, and the other end is connected to the input end of the voltage conversion unit 11, and the control end of the first switch S1 is connected to the output end of the second comparator COMP2; one end of the second switch S2 is connected to the input end of the soft start unit 12, and the other end is connected to the input end of the voltage conversion unit 11, and the control end of the second switch S2 is connected to the output end of the second comparator COMP2.

[0083] For example, taking the case where the first switch S1 is a PMOS transistor and the second switch S2 is an NMOS transistor, 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 target voltage Vout does not drop to a 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 disconnected 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 to the reference voltage VBG without having to access the reference voltage VBG through the soft start unit 12. This is equivalent to shielding the soft start unit 12 of the first voltage conversion module 101, thereby enabling the voltage conversion unit 11 of the first voltage conversion module 101 to quickly output the target voltage Vout and quickly complete the switching process of the power supply 200.

[0084] When the first voltage conversion module 101 and the second voltage conversion module 102 are both not working, and the voltage selection module 20 selects the first voltage conversion module 101 to start up normally and power on to output the target voltage Vout, the target voltage Vout is at a low level at this time, so the second comparator COMP2 outputs a low-level signal, and then the second comparator COMP2 can control the first switch S1 to be closed and the second switch S2 to be open. 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 is used to prevent the overshoot voltage phenomenon that occurs during the power-on process of the first voltage conversion module 101.

[0085] It is understandable that the implementation of the soft start shielding module 30 is not limited thereto. For example, see Figure 14 , Figure 14 Another schematic diagram of the power supply selection circuit 100 in an embodiment of the present application is shown. The soft start shielding module 30 can also receive system instructions 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.

[0086] In some embodiments of the present application, see Figure 15 , Figure 15 Another schematic diagram of the power supply selection circuit 100 in an embodiment of the present application is shown. The power supply selection circuit 100 also includes a reset detection module 40; the reset detection module 40 is used to detect the output voltage of at least one power supply 200 and / or the internal voltage of at least one voltage conversion module 10, so as to output a reset indication signal Rest after the output voltage of at least one power supply 200 and / or the internal voltage of at least one voltage conversion module 10 loses power.

[0087] It should be noted that when the power supply selection circuit 100 is connected to only one power source 200 (e.g., the internal power source 201), if the connected power source 200 is out of power, due to the presence of a large external capacitor in the voltage conversion module 10, the reference voltage VBG may drop while the target voltage Vout remains high. This can easily lead to a delay in detecting the target voltage Vout, and the system (e.g., an MCU) may not be reset in time. In the above embodiment, the reset detection module 40 can detect the output voltage of the power source 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 source 201, and the reset detection module 40 can detect the output voltage of the charge pump within 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 source 200 and / or the internal voltage of the voltage conversion module 10 loses power, thereby avoiding the phenomenon that the system may not be reset due to a delay in detecting the target voltage Vout.

[0088] Exemplarily, the reset detection module 40 may include analog comparison voltages such as comparators and / or digital circuits such as analog-to-digital converters to determine or measure the output voltage of the power supply 200 and / or the internal voltage of the voltage conversion module 10 .

[0089] It can be understood that the above embodiment uses the reset indication signal Rest output by the reset detection module 40 as the reset signal of the system. In some possible embodiments, the reset indication signal Rest may also be used as the reset signal of the system. Figure 13 The output signal of the second comparator COMP2 is used as the reset signal of the system. In 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 used as the reset signal. For example, the reset indication signal Rest and the output signal of the second comparator COMP2 are connected to a gate circuit (such as an AND gate, an OR gate, etc.), and the signal output by the gate circuit is used as the reset signal of the system.

[0090] In some embodiments of the present application, see Figure 16 , Figure 16 Another schematic diagram of the power supply selection circuit 100 in an embodiment of the present application is shown. The power supply selection circuit 100 also 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 multiple 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 multiple power supplies 200, so that the voltage conversion module 10 can output a target voltage Vout according to the output voltage of the corresponding power supply 200 and the reference voltage VBG.

[0091] Exemplarily, the maximum voltage selection module 50 may include but is not limited to a maximum voltage selection circuit composed of a diode or a maximum voltage selection circuit composed of a comparator and a switch; the bandgap reference module 60 may include but is not limited to a current mirror type bandgap reference circuit or an operational amplifier type bandgap reference circuit.

[0092] It is understandable that the implementation of the power supply selection circuit 100 providing the reference voltage VBG for the voltage conversion module 10 is not limited to this. For example, see Figure 17 , Figure 17 Another schematic diagram of the power supply selection circuit 100 in an embodiment of the present application is shown. The power supply selection circuit 100 may further be provided with multiple bandgap reference modules 60 to provide a reference voltage VBG for each voltage conversion module 10 .

[0093] The present application also provides a chip including the aforementioned power supply selection circuit 100. An integrated circuit (IC) is also referred to as a chip, and the chip may be, but is not limited to, a SOC (System on Chip) chip or a SIP (System in Package) chip. Because the chip includes the power supply selection circuit 100 of the aforementioned embodiment, it possesses all the beneficial effects of the power supply selection circuit 100 of the aforementioned embodiment and will not be further elaborated here.

[0094] The embodiment of the present application also provides an electronic device, which includes a device body and a chip as described above provided in the device body. The electronic device can be, but is not limited to, a weight scale, a body fat scale, a nutrition scale, an infrared electronic thermometer, a pulse oximeter, a body composition analyzer, a mobile power supply 200, a wireless charger, a fast charger, a car charger, an adapter, a display, a USB (Universal Serial Bus) docking station, a stylus, a true wireless headset, a car central control panel, a car, a smart wearable device, a mobile terminal, and a smart home device. Smart wearable devices include, but are not limited to, smart watches, smart bracelets, and cervical massagers. Mobile terminals include, but are not limited to, smart phones, laptops, tablet computers, and POS (point of sales terminal) machines. Smart home devices include, but are not limited to, smart sockets, smart rice cookers, smart sweepers, and smart lights.

[0095] The above is only a preferred embodiment of the present application and does not constitute any form of limitation to the present application. Although the present application has been disclosed as above with preferred embodiments, it is not intended to limit the present application. Any person skilled in the art can make some changes or modifications to equivalent embodiments using the technical contents disclosed above without departing from the scope of the technical solution of the present application. However, any brief modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present application without departing from the content of the technical solution of the present application are still within the scope of the technical solution of the present application.

Claims

1. A power supply selection circuit, characterized in that: The power supply selection circuit is used to select one of multiple power supplies to supply power and output a target voltage. The power supply selection circuit includes: a plurality of voltage conversion modules, each of the voltage conversion modules comprising a voltage conversion unit and a soft start unit, the voltage conversion unit being configured to convert the output voltage of the power supply into the target voltage, the soft start unit being configured to reduce an overshoot voltage generated by the voltage conversion unit during power-on; 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; a soft start shielding module, the soft start shielding module being used to control the soft start unit of at least one of the voltage conversion modules; When the voltage selection module switches one of the at least one voltage conversion module to serve 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 according to claim 1, wherein: The multiple power supplies include at least one internal power supply and at least one external power supply, and the multiple voltage conversion modules include 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 according to claim 2, wherein: 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 of the first voltage conversion modules to outputting the target voltage from another of the first voltage conversion modules, the soft start shielding module shields the soft start unit of another of the first voltage conversion modules.

4. The power supply selection circuit according to claim 2, wherein: When the first output voltage of the internal power supply is lower 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 according to claim 2, wherein: The voltage selection module includes a first comparator; The first input end of the first comparator is used to access a first set voltage, the second input end of the first comparator is used to access a first output voltage of the internal power supply, the output end of the first comparator is connected to the first voltage conversion module, and the output end of the first comparator is connected to the second voltage conversion module.

6. The power supply selection circuit according to claim 5, wherein: 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 a 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 a second system control signal; The output end of the first multiplexer is connected to the first voltage conversion module, the output end of the second multiplexer is connected to the second voltage conversion module, and the control ends of the first multiplexer and the second multiplexer are used to access system selection signals.

7. The power supply selection circuit according to claim 2, wherein: When the first voltage conversion module outputs the target voltage, the voltage selection module stops outputting the enable signal for controlling the first voltage conversion module and the second voltage conversion module in response to a system instruction; When the first output voltage of the internal power supply is lower than the first set voltage, the voltage selection module re-outputs the enable signal for controlling the first voltage conversion module and the second voltage conversion module in response to a system instruction.

8. The power supply selection circuit according to claim 1, wherein: The input end of the soft start shielding module is connected to the output ends of the plurality of voltage conversion modules; An output end 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 according to claim 8, wherein: 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 voltage conversion unit; One end of the first switch is connected to the output end of the soft start unit, and the other end is connected to the input end of the voltage conversion unit, and the control end of the first switch is connected to the output end of the second comparator; One end of the second switch is connected to the input end of the soft start unit, and the other end is connected to the input end of the voltage conversion unit. The control end of the second switch is connected to the output end of the second comparator.

10. The power supply selection circuit according to claim 1, wherein: 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 loses power.

11. The power supply selection circuit according to claim 1, wherein: 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 one with the largest voltage among the multiple power supplies and input it into the bandgap reference module; The bandgap reference module is configured to output a reference voltage according to a maximum voltage among the plurality of power supplies, and the voltage conversion module outputs the target voltage according to an output voltage corresponding to the power supply and the reference voltage.

12. A chip, characterized in that: The method comprises the power supply selection circuit according to any one of claims 1 to 11.

13. An electronic device, characterized in that: Comprising the chip as claimed in claim 12.

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