Power supply circuit and electronic equipment supporting multi-power input

Abstract

The invention provides a power supply circuit and electronic equipment supporting multi-power input, and relates to the technical field of power circuits, in particular to the field of circuit protection. According to the specific implementation scheme, in the power supply circuit, the first end of a main power source control module is used for being connected with a main power source, the second end of the main power source control module is used for being connected with a load, and the first end of the main power source control module and the second end of the main power source control module are conducted when the main power source is powered on; a first end of the first auxiliary power supply control module is used for connecting a first auxiliary power supply, a second end of the first auxiliary power supply control module is used for connecting a load, a third end of the first auxiliary power supply control module is connected with a main power supply through a first resistor, and the third end of the first auxiliary power supply control module is grounded through a second resistor; the first end of the first auxiliary power supply control module and the second end of the first auxiliary power supply control module are conducted when the first auxiliary power supply is powered on and the third end voltage of the first auxiliary power supply control module is lower than a first value.

Description

Technical Field

[0001] The present disclosure relates to the technical field of power supply circuits, and in particular to the field of circuit protection. Background Art

[0002] In consumer electronics, automotive electronics, and industrial electronics, multiple input power supply circuits are used in many scenarios. Among them, multiple input power supplies have priority order requirements. Specifically, when both input power supplies are present, the main power supply provides power; when only any one input power supply is present, that input power supply provides power. In order to achieve the above priority order requirements, the auxiliary power supply control module needs to be connected to the main power supply, but the voltage of the main power supply is larger than that of the auxiliary power supply, which can easily affect the auxiliary power supply control module. Summary of the invention

[0003] The present disclosure provides a power supply circuit, including a main power supply control module, a first auxiliary power supply control module, a first resistor and a second resistor.

[0004] According to one aspect of the present disclosure, there is provided a power supply circuit, comprising a main power supply control module, a first auxiliary power supply control module, a first resistor and a second resistor;

[0005] Wherein, the first end of the main power control module is used to connect the main power supply, the second end of the main power control module is used to connect the load, and the first end of the main power control module and the second end of the main power control module are connected when the main power supply is powered on;

[0006] The first end of the first auxiliary power supply control module is used to connect the first auxiliary power supply, the second end of the first auxiliary power supply control module is used to connect the load, the third end of the first auxiliary power supply control module is connected to the main power supply through the first resistor, and the third end of the first auxiliary power supply control module is grounded through the second resistor; the first end of the first auxiliary power supply control module and the second end of the first auxiliary power supply control module are turned on when the first auxiliary power supply is powered on and the voltage of the third end of the first auxiliary power supply control module is lower than the first value.

[0007] According to the technical solution disclosed in the present invention, the first auxiliary power supply control module realizes state switching according to the main power supply by connecting the main power supply and the ground. At the same time, a first resistor is added between the first auxiliary power supply control module and the main power supply, which can protect the auxiliary power supply control module when the main power supply is powered on, thereby improving the stability and reliability of the power supply circuit.

[0008] It should be understood that the content described in this section is not intended to identify the key or important features of the embodiments of the present disclosure, nor is it intended to limit the scope of the present disclosure. Other features of the present disclosure will become easily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] The accompanying drawings are used to better understand the present solution and do not constitute a limitation of the present disclosure.

[0010] Figure 1 is a schematic diagram of the structure of a power supply circuit according to an embodiment of the present disclosure;

[0011] Figure 2 is a schematic diagram of the structure of a P-MOSFET according to the present disclosure;

[0012] Figure 3 is a structural schematic diagram of a power supply circuit according to another embodiment of the present disclosure;

[0013] Figure 4 is a structural schematic diagram of a power supply circuit according to another embodiment of the present disclosure;

[0014] Figure 5 is a schematic diagram of the structure of an N-MOSFET according to the present disclosure;

[0015] Figure 6 is a structural schematic diagram of a power supply circuit according to another embodiment of the present disclosure;

[0016] Figure 7 is a schematic diagram of an electronic device according to an embodiment of the present disclosure. DETAILED DESCRIPTION

[0017] The following is a description of exemplary embodiments of the present disclosure in conjunction with the accompanying drawings, including various details of the embodiments of the present disclosure to facilitate understanding, which should be considered as merely exemplary. Therefore, it should be recognized by those of ordinary skill in the art that various changes and modifications may be made to the embodiments described herein without departing from the scope of the present disclosure. Similarly, for the sake of clarity and conciseness, the description of well-known functions and structures is omitted in the following description.

[0018] The current multi-input power switching circuit design mostly adopts a series diode circuit or a dedicated power management chip solution.

[0019] The series diode circuit, that is, each input power supply is connected in series with a power diode, and then the cathodes of all diodes are connected to the rear-end load; the power diode can prevent the current from flowing back from the rear-end load end to the input end, and can realize the function of seamless switching of multiple input power supplies. Since the power diode is connected in series in the power supply circuit and there is a voltage drop in the diode, there will definitely be power loss; when the input current is large, the power loss of the power diode will also be very large. The defects of the power diode series circuit design include: first, the voltage of the input power supply will drop after passing through the power diode, for example, it will drop by about 0.7V (volts); second, the diode has power dissipation, which reduces the power supply efficiency of the input power supply; third, the power dissipation of the diode will also cause heat dissipation design and environmental temperature rise problems.

[0020] If a dedicated power management chip is used, the cost is high, the internal logic function is complex, the adaptability to general consumer electronics and automotive electronics is poor, and the static power consumption cannot be adjusted. In addition, since the input voltage of the power management chip is limited, it cannot support a particularly wide range of input voltages.

[0021] The technical solution of the embodiment of the present disclosure is described below with reference to the accompanying drawings. Figure 1 As shown, an embodiment of the present disclosure provides a power supply circuit, including a main power control module 10, a first auxiliary power control module 20, a first resistor R1 and a second resistor R2.

[0022] The first end of the main power control module 10 is used to connect the main power, and the second end of the main power control module is used to connect the load. The first end of the main power control module 10 and the second end of the main power control module 10 are connected when the main power is powered on. That is to say, when the main power is powered on, a path is formed between the first end and the second end of the main power control module 10, thereby forming a path between the main power and the load, and the load can obtain power from the main power.

[0023] The first end of the first auxiliary power control module 20 is used to connect the first auxiliary power supply, the second end of the first auxiliary power control module 20 is used to connect the load, the third end of the first auxiliary power control module 20 is connected to the main power supply through the first resistor R1, and the third end of the first auxiliary power control module 20 is grounded through the second resistor R2; the first end of the first auxiliary power control module 20 and the second end of the first auxiliary power control module 20 are connected when the first auxiliary power supply is powered on and the voltage of the third end of the first auxiliary power control module 20 is lower than the first value. That is to say, when the first auxiliary power supply is powered on and the voltage of the third end of the first auxiliary power control module 20 is lower than the first value, a path is formed between the first end and the second end of the first auxiliary power control module 20, thereby forming a path between the first auxiliary power supply and the load, and the load can obtain power from the first auxiliary power supply.

[0024] In the embodiment of the present disclosure, the main power control module 10 may include at least two interfaces or ports, namely, the first end and the second end of the main power control module 10 (the first and second do not represent the order, current direction, etc., and are only used to distinguish different ports). When the main power is powered on, that is, when the main power has voltage, it is in the on state, and the current input by the main power can enter the main power control module 10 through the first end of the main power control module 10, and be output to the load through the second end of the main power control module 10.

[0025] In the embodiment of the present disclosure, the first auxiliary power supply control module 20 may include three interfaces / ports, namely, the first end, the second end and the third end of the first auxiliary power supply control module 20. When the first auxiliary power supply has no voltage, the first end and the second end of the first auxiliary power supply control module 20 are not conductive, that is, in a cut-off state. At this time, if the main power supply is powered on, the main power supply supplies power to the load.

[0026] When the main power supply is not powered on and the first auxiliary power supply is powered on, since the third end of the first auxiliary power supply control module 20 is grounded through the second resistor R2, the voltage of the third end of the first auxiliary power supply control module 20 will be pulled down, so that the first end and the second end of the first auxiliary power supply control module 20 can be turned on, and the current input by the first auxiliary power supply can be output to the load through the first auxiliary power supply control module 20.

[0027] When both the main power supply and the first auxiliary power supply are powered on, since the third end of the first auxiliary power supply control module 20 is connected to the main power supply through the first resistor R1, the voltage of the third end of the first auxiliary power supply control module 20 is pulled up by the main power supply, so that the first end and the second end of the first auxiliary power supply control module 20 are not conductive, that is, in a cut-off state, and the main power supply supplies power to the load.

[0028] In addition, in the embodiment of the present disclosure, a first resistor R1 is provided between the main power supply and the third end of the first auxiliary power supply control module 20. Compared with the direct connection between the main power supply and the third end of the first auxiliary power supply control module 20, the provision of the first resistor R1 can make the voltage of the third end of the first auxiliary power supply control module 20 lower than the voltage of the main power supply. In this way, the protection of the first auxiliary power supply control module 20 can be achieved.

[0029] It can be understood that the voltage at the third terminal of the first auxiliary power control module 20 can be determined based on the resistance values ​​of the first resistor R1 and the second resistor R2, and the voltage is the voltage division result of the first resistor R1 and the second resistor R2. By adjusting the resistance values ​​of the first resistor R1 and the second resistor R2, the voltage at the third terminal of the first auxiliary power control module 20 can be higher than the first value when the main power is powered on.

[0030] It can be understood that in the above embodiment, the first value is a critical value or a threshold value for distinguishing whether the voltage at the third terminal of the first auxiliary power supply control module 20 is high or low. The first value can be a fixed value, or it can be a voltage value at a certain position determined according to the circuit state. For example, the first value can be a voltage value set according to actual needs, R1, R2, etc., or the first value can be a voltage value at the second terminal of the first auxiliary power supply control module 20. In actual applications, the first value can be set in different ways according to the specific design of each module of the power supply circuit, and the embodiments of the present disclosure are not limited to this.

[0031] Optionally, the first resistor R1 and the second resistor R2 can also be flexibly designed as required. Figure 1 As shown, the first resistor R1 and the second resistor R2 may be a single resistor. Alternatively, the first resistor R1 and / or the second resistor R2 may also be obtained by connecting a plurality of resistors in series and / or in parallel.

[0032] In the disclosed embodiment, the main power supply has a higher power supply priority, and the main power supply voltage may be greater than the first auxiliary power supply voltage. For example, the main power supply voltage may be 12V (volts), and the first auxiliary power supply voltage may be 3V or 5V, etc.

[0033] In the embodiments of the present disclosure, the power supply circuit can be applied to the input power supply switching control of electronic products in various industries. For example, the power supply circuit can be applied to consumer electronics, automotive electronics, industrial electronics and other products.

[0034] According to the technical solution of the embodiment of the present disclosure, at the moment when the main power supply is powered on, the current output by the main power supply flows through the first resistor R1, and the first resistor R1 can limit the charging current of the third terminal of the first auxiliary power supply control module 20 to prevent the instantaneous driving current from being too large and damaging the first auxiliary power supply control module 20. In addition, the instantaneous charging capacitor is equivalent to a short circuit, and the current is very large. At the same time, a large transient current needs to be obtained from the power supply end (main power supply), and the power supply end may not be able to provide such a large current. At this time, the first resistor is also a protection for the power supply end. In addition, in some scenarios, for example, when the main power supply is a wall-plug power adapter, due to the long wiring harness of the wall-plug power adapter, parasitic inductance may also exist in the above-mentioned power supply circuit, and the overall parasitic inductance is large. If there is still parasitic capacitance in the circuit, an equivalent LC low-pass filter circuit will be formed, and a very high gain will be generated near the resonant frequency point. At the moment when the main power supply is powered on, the frequency of the control signal existing at the third terminal of the first auxiliary power supply control module 20 is very rich, and there may be signals near the resonant frequency point, so it is possible to generate resonance, thereby generating oscillation, and the first resistor R1 can absorb this oscillation signal to protect the first auxiliary power supply control module 20. It can be seen that the embodiment of the present disclosure can also improve the stability, reliability and safety of the power supply circuit while meeting the power supply priority requirements of the primary and auxiliary power supplies.

[0035] In some embodiments, there is no limitation on the implementation of the first auxiliary power control module 20 and the main power control module 10. For example, the first auxiliary power control module 20 can be implemented by a power management chip. For another example, the main power control module 10 can be implemented by a power management chip.

[0036] In some embodiments, the first auxiliary power control module 20 includes a first P-type field effect transistor Q1. Exemplarily, the P-type field effect transistor is a P-MOSFET (P-channel Metal-Oxide-Semiconductor Field-EffectTransistor), which can also be called a P MOS transistor. The drain of the first P-type field effect transistor Q1 is connected to the first end of the first auxiliary power control module, the source of the first P-type field effect transistor Q1 is connected to the second end of the first auxiliary power control module, and the gate of the first P-type field effect transistor Q1 is connected to the third end of the first auxiliary power control module. In one example, as Figure 2 As shown, pins 1-3 of the P-MOSFET are the source of the first P-type field effect transistor Q1, connected to the second end of the first auxiliary power control module 20, pin 4 of the P-MOSFET can be the gate of the first P-type field effect transistor Q1, connected to the third end of the first auxiliary power control module 20, and pins 5-8 of the P-MOSFET can be the drain of the first P-type field effect transistor Q1, connected to the first end of the first auxiliary power control module 20.

[0037] According to the above embodiment, when the first auxiliary power supply is powered on and the main power supply has no voltage, the drain voltage of the first P-type field effect transistor Q1 is the voltage input by the first auxiliary power supply, and the drain and source of the first P-type field effect transistor Q1 can form a conductive channel, that is, a body diode, so that the first P-type field effect transistor Q1 is unidirectionally conducted, and the voltage input by the first auxiliary power supply is output to the load after passing through the body diode. At the same time, the gate of the first P-type field effect transistor Q1 is pulled down to 0V, and the gate voltage of the first P-type field effect transistor Q1 is much lower than the source voltage of the first P-type field effect transistor Q1. The first P-type field effect transistor Q1 can be bidirectionally conducted, and the voltage input by the first auxiliary power supply is no longer output to the rear-end load after passing through the body diode, but is output to the load after passing through the internal resistance of the first P-type field effect transistor Q1.

[0038] When both the main power supply and the first auxiliary power supply are powered on, since the main power supply voltage is higher, the gate voltage of the first P-type field effect transistor Q1 is the power supply voltage input by the main power supply. After voltage division by the first resistor R1 and the second resistor R2, the gate voltage of the first P-type field effect transistor Q1 is slightly lower than the power supply voltage input by the main power supply, but higher than the source voltage of the first P-type field effect transistor Q1, and the first P-type field effect transistor Q1 is in a completely cut-off state. At this time, the main power supply provides the load with a power supply voltage. If the power supply voltage at the input end of the main power supply disappears, the first auxiliary power supply can be seamlessly switched to provide the load with a power supply voltage.

[0039] According to the technical solution of the embodiment of the present disclosure, the function of the first auxiliary power control module 20 can be implemented by the first P-type field effect transistor Q1, thereby simplifying the circuit and optimizing power consumption.

[0040] In some embodiments, Figure 3 As shown, the power supply circuit also includes a first anti-backflow switch module 30; the first anti-backflow switch module 30 is arranged between the first auxiliary power supply and the first auxiliary power supply control module 20, and the first anti-backflow switch module 30 is cut off when the first auxiliary power supply has no voltage.

[0041] It can be understood that when the main power supply is powered on and the first auxiliary power supply has no voltage, the second terminal voltage of the first auxiliary power supply control module 20 is the voltage supplied by the main power supply to the load, and this voltage will be greater than the first terminal voltage of the first auxiliary power supply control module 20. In some scenarios, there may be a situation where the load voltage is backflowed / reversely fed to the auxiliary power supply. By setting the first anti-backflow switch module 30, when the main power supply is powered on and the first auxiliary power supply has no voltage, the first anti-backflow switch module 30 is in the cut-off state, which can prevent the current output by the main power supply from being reversely fed to the first auxiliary power supply. When the first auxiliary power supply is powered on and the main power supply has no voltage, the first anti-backflow switch module 30 is in the on state, and the power output by the first auxiliary power supply flows through the first anti-backflow switch module 30 to the first end of the first auxiliary power supply control module 20.

[0042] It can be understood that when both the main power supply and the first auxiliary power supply are powered on, the first anti-backfeed switch module 30 is in the on state, but because the first auxiliary power supply itself has a certain voltage and the internal resistance of the first anti-backfeed switch module 30, the first auxiliary power supply can also be effectively prevented from being affected by backfeed.

[0043] According to the technical solution of the embodiment of the present disclosure, the first anti-backflow switch module 30 can be cut off when the first auxiliary power supply has no voltage, preventing the current output by the main power supply from backflowing to the first auxiliary power supply, preventing damage to the first auxiliary power supply, and improving the reliability and safety of the power supply circuit.

[0044] In some embodiments, Figure 4As shown, the first anti-backflow switch module 30 includes a second P-type field effect transistor Q2 and a first N-type field effect transistor Q3, a third resistor, a fourth resistor and a fifth resistor. The embodiment of the present disclosure does not limit the implementation of the third resistor, the fourth resistor and the fifth resistor (including the number and resistance of the resistors, etc.). For example, Figure 4 As shown, the fourth resistor includes a resistor R4, the third resistor can be obtained by connecting a resistor R31 and a resistor R32 in parallel, and the fifth resistor can be obtained by connecting a resistor R51 and a resistor R52 in parallel.

[0045] The source of the second P-type field effect transistor Q2 is used to connect to the first auxiliary power supply, and the drain of the second P-type field effect transistor Q2 is connected to the first auxiliary power supply control module 20;

[0046] The gate of the second P-type field effect transistor Q2 is connected to the drain of the first N-type field effect transistor Q3 through a fourth resistor, and the drain of the first N-type field effect transistor Q3 is also connected to the source of the second P-type field effect transistor Q2 through a fifth resistor;

[0047] The source of the first N-type field effect transistor Q3 is grounded; the gate of the first N-type field effect transistor Q3 is connected to the first end of the third resistor, the first end of the third resistor is also connected to the source of the second P-type field effect transistor Q2, and the second end of the third resistor is grounded.

[0048] In the disclosed embodiment, according to the above design, when the first auxiliary power supply has no voltage, the source voltage of the second P-type field effect transistor Q2 and the gate voltage of the second P-type field effect transistor Q2 have no voltage, and the first auxiliary power supply control module is in a cut-off state, which can prevent the current output by the main power supply from flowing back to the first auxiliary power supply. When the first auxiliary power supply is powered on, the second P-type field effect transistor Q2 is in a conducting state, so that the current provided by the first auxiliary power supply can reach the auxiliary power supply when the main power supply has no voltage, and when the main power supply has voltage, the internal resistance of the second P-type field effect transistor Q2 can also be used to prevent slight backflow caused by the voltage difference (for example, slight backflow caused when the main power supply voltage is greater than the first auxiliary power supply voltage).

[0049] Specifically, when the first auxiliary power supply is powered on, the source voltage of the second P-type field effect transistor Q2 is the voltage input by the first auxiliary power supply, and the drain and source of the second P-type field effect transistor Q2 can form a conductive channel, that is, a body diode, so that the second P-type field effect transistor Q2 is unidirectionally conducted, and the voltage input by the first auxiliary power supply is output to the first auxiliary power supply control module 20 after passing through the body diode. At the same time, the gate of the first N-type field effect transistor Q3 can be gradually turned on under charging, and the gate voltage of the second P-type field effect transistor Q2 can be pulled down to 0V through the third resistor. Under the voltage division of the fourth resistor and the fifth resistor, the second P-type field effect transistor Q2 can be bidirectionally conducted, and the voltage input by the first auxiliary power supply is no longer output to the first auxiliary power supply control module 20 after passing through the body diode, but is output to the first auxiliary power supply control module 20 after passing through the internal resistance of the second P-type field effect transistor Q2.

[0050] When the main power supply is powered on, the main power supply supplies power to the load. At this time, the source voltage of the first P-type field effect transistor Q1 is the voltage input to the main power supply. The gate voltage of the first P-type field effect transistor Q1 is slightly lower than the source voltage due to the voltage division between the first resistor R1 and the second resistor R2. The first P-type field effect transistor Q1 is in a slightly turned-on state. The drain backflow current of the first P-type field effect transistor Q1 to the drain of the second P-type field effect transistor Q2 can prevent the first auxiliary power supply from being affected by the backflow through the internal resistance of the second P-type field effect transistor Q2.

[0051] In an example, the first N-type field effect transistor Q3 may be an N-MOSFET (N-channel Metal-Oxide-Semiconductor Field-Effect Transistor), such as Figure 5 As shown, pin 1 of the N-MOSFET can be the drain of the first N-type field effect transistor Q3 connected to the gate of the first N-type field effect transistor Q3 through the fourth resistor R4, pin 2 of the N-MOSFET can be the source of the first N-type field effect transistor Q3 grounded, and pin 3 of the N-MOSFET can be the gate of the first N-type field effect transistor Q3 connected to the first auxiliary power supply.

[0052] In some embodiments, Figure 4 As shown, a twelfth resistor R12 can be set between the gate of the first N-type field effect transistor Q3 and the first auxiliary power supply. The gate of the first N-type field effect transistor Q3 can be slowly charged under the current limiting of the twelfth resistor R12. The twelfth resistor R12 can protect the first N-type field effect transistor Q3 and improve the service life of the first N-type field effect transistor Q3.

[0053] In some embodiments, Figure 4 As shown, the second resistor can be obtained by connecting resistors R21 and R22 in parallel.

[0054] According to the technical solution of the embodiment of the present disclosure, the second P-type field effect transistor Q2 can be used to prevent the first auxiliary power supply from being affected by backflow, thereby preventing damage to the first auxiliary power supply and improving the reliability and safety of the power supply circuit.

[0055] In some embodiments, Figure 4 As shown, the main power control module 10 includes: a third P-type field effect transistor Q4 and a second N-type field effect transistor Q5, a ninth resistor, a tenth resistor R10 and an eleventh resistor; as an example but not a limitation, the ninth resistor can be obtained by connecting resistors R91 and R92 in parallel, and the eleventh resistor can be obtained by connecting resistors R111 and R112 in parallel.

[0056] The drain of the third P-type field effect transistor Q4 is connected to the first end of the main power control module 10 , and the source of the third P-type field effect transistor Q4 is connected to the second end of the main power control module 10 .

[0057] The gate of the third P-type field effect transistor Q4 is connected to the drain of the second N-type field effect transistor Q5 through the tenth resistor R10, and the drain of the second N-type field effect transistor Q5 is also connected to the source of the third P-type field effect transistor Q4 through the eleventh resistor;

[0058] The source of the second N-type field effect transistor Q5 is grounded; the gate of the second N-type field effect transistor Q5 is connected to the first end of the ninth resistor, the first end of the ninth resistor is also connected to the drain of the third P-type field effect transistor Q4, and the second end of the ninth resistor is grounded.

[0059] In the disclosed embodiment, when the main power supply is powered on, the drain voltage of the third P-type field effect transistor Q4 is the voltage of the first auxiliary power supply input, and the drain and source of the third P-type field effect transistor Q4 can form a conductive channel, that is, a body diode, so that the third P-type field effect transistor Q4 is unidirectionally conducted, and the voltage input by the main power supply is output to the load after passing through the body diode. At the same time, the gate of the second N-type field effect transistor Q5 can be gradually turned on under charging, and the gate voltage of the second P-type field effect transistor Q2 can be pulled down to 0V through the ninth resistor. Under the voltage division of the tenth resistor R10 and the eleventh resistor, the third P-type field effect transistor Q4 can be bidirectionally conducted, and the voltage input by the main power supply is no longer output to the load after passing through the body diode, but is output to the load after passing through the internal resistance of the third P-type field effect transistor Q4.

[0060] In some embodiments, Figure 4 As shown, a thirteenth resistor R13 can be set between the gate of the second N-type field effect transistor Q5 and the main power supply. The gate of the second N-type field effect transistor Q5 can be slowly charged under the current limiting of the thirteenth resistor R13. The thirteenth resistor R13 can protect the second N-type field effect transistor Q5 and improve the service life of the second N-type field effect transistor Q5.

[0061] Optionally, the number and resistance value of the ninth resistor, the tenth resistor R10 and the eleventh resistor are not limited and can be selected and adjusted as needed. Figure 4 As shown, the tenth resistor R10 may be one, the ninth resistor may be a resistor R91 and a resistor R92 connected in parallel, and the eleventh resistor may be a resistor R111 and a resistor R112 connected in parallel.

[0062] According to the technical solution of the embodiment of the present disclosure, the main power supply can supply power to the load through the third P-type field effect transistor Q4 and the second N-type field effect transistor Q5, thereby further optimizing power consumption.

[0063] In some embodiments, Figure 6 As shown, the power supply circuit further includes a second auxiliary power supply control module 60, a sixth resistor R6, a seventh resistor R7, an eighth resistor R8, a first diode D1 and a second diode D2;

[0064] The first end of the second auxiliary power control module 60 is used to connect the second auxiliary power supply, and the second end of the second auxiliary power control module is used to connect the load; the third end of the second auxiliary power control module 60 is connected to the cathode (also called cathode) of the first diode D1 and the cathode of the second diode D2, and the third end of the second auxiliary power control module is grounded through the eighth resistor R8;

[0065] The positive electrode (also referred to as the anode) of the first diode D1 is connected to the first end of the sixth resistor R6, and the second end of the sixth resistor R6 is used to connect to the main power supply;

[0066] The anode of the second diode D2 is connected to the first end of the seventh resistor R7, and the second end of the seventh resistor R7 is used to connect to the first auxiliary power supply;

[0067] The second auxiliary power supply control module 60 is used to turn on when the second auxiliary power supply is powered on and the voltage at the third terminal of the second auxiliary power supply control module is lower than the second value. It can be understood that the second value is a critical value or a threshold value for distinguishing whether the voltage at the third terminal of the second auxiliary power supply control module 60 is high or low. The second value can be a fixed value, or it can be a voltage value at a certain position determined according to the circuit state. For example, the second value can be a voltage value set according to actual needs, R6, R7, R8, etc., or the second value can be the voltage value of the second terminal of the second auxiliary power supply control module 60. In actual applications, the second value can be set in different ways according to the specific design of each module of the power supply circuit, and the embodiments of the present disclosure are not limited to this.

[0068] In the embodiment of the present disclosure, the priority of the second auxiliary power supply is lower than that of the first auxiliary power supply and the main power supply, that is, when the second auxiliary power supply is powered on and the first auxiliary power supply and the main power supply have no voltage, the second auxiliary power supply supplies power to the load. When the second auxiliary power supply is powered on and the first auxiliary power supply and / or the main power supply are powered on, the first auxiliary power supply or the main power supply supplies power to the load.

[0069] In the embodiment of the present disclosure, by setting the sixth resistor R6 and the first diode D1 between the second auxiliary power control module and the main power supply, the second auxiliary power control module can be prevented from being affected by the main power supply. Similarly, by setting the seventh resistor R7 and the second diode D2 between the second auxiliary power control module and the first auxiliary power supply, the second auxiliary power control module can be prevented from being affected by the first auxiliary power supply. And by setting the first diode D1 and the second diode, the main power supply can be prevented from being connected in series with the first auxiliary power supply, thereby preventing current backflow.

[0070] Optionally, the devices included in the second auxiliary power supply control module 60 can be the same as the devices included in the first auxiliary power supply control module 20, that is, the second auxiliary power supply control module 60 can also include P-MOSFET, and seamless switching among the main power supply, the first auxiliary power supply and the second auxiliary power supply in the power supply circuit can be achieved through P-MOSFET.

[0071] According to the technical solution of the embodiment of the present disclosure, the load can be powered by the second auxiliary power supply and the second auxiliary power supply control module, thereby improving the reliability of the power supply circuit. In addition, the second auxiliary power supply control module can be protected by the resistor and the diode between the second auxiliary power supply control module and the main power supply and the first auxiliary power supply to prevent damage to the second auxiliary power supply control module.

[0072] In some embodiments, the power supply circuit further includes a second anti-backfeed switch module; the second anti-backfeed switch module is disposed between the second auxiliary power supply and the second auxiliary power supply control module, and the second anti-backfeed switch module is cut off when the second auxiliary power supply has no voltage.

[0073] In the disclosed embodiment, when the main power supply and / or the first auxiliary power supply are powered on, the second auxiliary power supply control module will feed back current to the second anti-backflow switch module. When the second auxiliary power supply has no voltage, the second anti-backflow switch module is in an off state, preventing the current output by the main power supply and / or the first auxiliary power supply from backflowing to the first auxiliary power supply. When the second auxiliary power supply is powered on, the second anti-backflow module is in an on state, and the power output by the second auxiliary power supply flows through the second anti-backflow module to the first end of the second auxiliary power supply control module.

[0074] It can be understood that when the second auxiliary power supply is powered on, and the main power supply and / or the first auxiliary power supply are powered on, the second anti-backflow module is in a conducting state, but the backflow situation is not serious, and the internal resistance of the second anti-backflow module can be used to prevent the second auxiliary power supply from being affected by backflow.

[0075] Optionally, the devices included in the second anti-backflow switch module can be the same as the devices included in the first anti-backflow switch module 30, that is, the second auxiliary power supply control module can also include P-MOSFET and N-MOSFET, and the P-MOSFET and N-MOSFET can prevent damage to the second auxiliary power supply.

[0076] According to the technical solution of the embodiment of the present disclosure, the second anti-backflow switch module can be cut off when the second auxiliary power supply has no voltage, preventing the current output by the main power supply and / or the first auxiliary power supply from backflowing to the second auxiliary power supply, preventing damage to the second auxiliary power supply, and improving the reliability and safety of the power supply circuit.

[0077] In some embodiments, the resistance of the second resistor R2 is greater than that of the first resistor R1. Thus, when the main power supply is powered on, the voltage divided between the second resistor R2 and the first resistor R1 is high enough to increase the voltage of the third terminal of the first auxiliary power supply control module 20.

[0078] According to the technical solution of the embodiment of the present disclosure, since the resistance of the second resistor R2 is greater than the resistance of the first resistor R1, the voltage division of the second resistor R2 is higher, which can ensure that the main power supply is powered when the main power supply is powered on, thereby realizing seamless switching between the main and auxiliary power supplies.

[0079] In some embodiments, the main power source includes an output of a power adapter. Optionally, the power adapter can be any type of power adapter, such as a wall-mounted power adapter, an adjustable power adapter, etc. The first auxiliary power source includes a battery. Optionally, the battery can be any type of battery, such as a primary battery, a storage battery, etc.

[0080] In actual application scenarios, the wiring harness of the wall-plug power adapter is relatively long. Combined with the PCB (Printed Circuit Board) routing, the electrode leads inside the MOS tube will also have inductance parasitics, and the overall parasitic inductance is relatively large. There is parasitic capacitance between the MOS tube poles, and there is also parasitic capacitance in the PCB routing. The MOS tube switching circuit is equivalent to an LC low-pass filter circuit. A very high gain will be generated near the resonant frequency point. At the moment the adapter is inserted, the P MOS gate control signal in the first auxiliary power supply control module 20 has a very rich frequency, and there may be signals near the resonant frequency point, so resonance may occur, thereby generating oscillations at the P MOS gate. The first resistor is a damper that absorbs this oscillation signal and protects the P MOS tube. It can be seen that according to the embodiment of the present disclosure, in the scenario of using a power adapter and a battery for dual power supply, the first resistor can be used to protect the power supply circuit and absorb the oscillation signal.

[0081] It can be understood that the embodiments of the present disclosure can also be applied to the main power supply and backup redundant power supply scenarios. In industrial electronic products, dual power supply designs of main power supply and backup redundant power supply are used in many scenarios. Among them, the backup redundant power supply can only provide input power to the back-end load after the main power supply is no longer in the effective range. That is, the main power supply has a higher priority. In this case, the circuit design of the embodiment of the present disclosure can be adopted to slightly lower the power supply voltage of the backup redundant power supply within the effective range. The two input power supplies can achieve seamless switching to provide power input for the back-end load.

[0082] In addition, the circuit design of the embodiment of the present disclosure can flexibly adjust circuit parameters to enhance adaptability. If the power P-MOSFET selects a model with lower on-resistance, it can reduce the power dissipation of the power supply, reduce the voltage drop loss of the P-MOSFET in the circuit of the input power supply, and reduce the temperature rise of the power P-MOSFET. If the power P-MOSFET selects a higher withstand voltage model, the circuit design can adapt to application scenarios with higher voltage input. If the circuit design selects a resistor with a higher resistance value, the static power dissipation of the circuit can also be further reduced.

[0083] The present disclosure also provides an electronic device. Figure 7 As shown, an embodiment of the present disclosure provides an electronic device 700 supporting multiple power inputs, and the electronic device includes a power supply circuit 710. The power supply circuit 710 can be a power supply circuit in any of the above embodiments.

[0084] It should be understood that the various forms of processes shown above can be used to reorder, add or delete steps. For example, the steps recorded in this disclosure can be executed in parallel, sequentially or in different orders, as long as the desired results of the technical solutions disclosed in this disclosure can be achieved, and this document does not limit this.

[0085] The above specific implementations do not constitute a limitation on the protection scope of the present disclosure. It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and substitutions can be made according to design requirements and other factors. Any modification, equivalent substitution and improvement made within the principles of the present disclosure shall be included in the protection scope of the present disclosure.

Claims

1. A power supply circuit, comprising a main power supply control module, a first auxiliary power supply control module, a first resistor and a second resistor; in, The first end of the main power control module is used to connect the main power supply, the second end of the main power control module is used to connect the load, and the first end of the main power control module and the second end of the main power control module are connected when the main power supply is powered on; The first end of the first auxiliary power supply control module is used to connect the first auxiliary power supply, the second end of the first auxiliary power supply control module is used to connect the load, the third end of the first auxiliary power supply control module is connected to the main power supply through the first resistor, and the third end of the first auxiliary power supply control module is grounded through the second resistor; the first end of the first auxiliary power supply control module and the second end of the first auxiliary power supply control module are turned on when the first auxiliary power supply is powered on and the voltage of the third end of the first auxiliary power supply control module is lower than the first value.

2. The power supply circuit according to claim 1, wherein: The first auxiliary power supply control module includes a first P-type field effect transistor, a drain of the first P-type field effect transistor is connected to a first end of the first auxiliary power supply control module, a source of the first P-type field effect transistor is connected to a second end of the first auxiliary power supply control module, and a gate of the first P-type field effect transistor is connected to a third end of the first auxiliary power supply control module.

3. The power supply circuit according to claim 1 or 2, wherein: The power supply circuit also includes a first anti-backfeeding switch module; the first anti-backfeeding switch module is arranged between the first auxiliary power supply and the first auxiliary power supply control module, and the first anti-backfeeding switch module is cut off when the first auxiliary power supply has no voltage.

4. The power supply circuit according to claim 3, wherein: The first anti-backflow switch module includes a second P-type field effect transistor and a first N-type field effect transistor, a third resistor, a fourth resistor and a fifth resistor; Wherein, the source of the second P-type field effect transistor is used to connect to the first auxiliary power supply, and the drain of the second P-type field effect transistor is connected to the first auxiliary power supply control module; The gate of the second P-type field effect transistor is connected to the drain of the first N-type field effect transistor through the fourth resistor, and the drain of the first N-type field effect transistor is also connected to the source of the second P-type field effect transistor through the fifth resistor; The source of the first N-type field effect transistor is grounded; the gate of the first N-type field effect transistor is connected to the first end of the third resistor, the first end of the third resistor is also connected to the source of the second P-type field effect transistor, and the second end of the third resistor is grounded.

5. The power supply circuit according to any one of claims 1 to 3, wherein: The power supply circuit also includes a second auxiliary power supply control module, a sixth resistor, a seventh resistor, an eighth resistor, a first diode and a second diode; The first end of the second auxiliary power supply control module is used to connect the second auxiliary power supply, and the second end of the second auxiliary power supply control module is used to connect the load; the third end of the second auxiliary power supply control module is connected to the cathode of the first diode and the cathode of the second diode, and the third end of the second auxiliary power supply control module is grounded through the eighth resistor; The anode of the first diode is connected to the first end of the sixth resistor, and the second end of the sixth resistor is used to connect to the main power supply; The anode of the second diode is connected to the first end of the seventh resistor, and the second end of the seventh resistor is used to connect to the first auxiliary power supply; The second auxiliary power supply control module is used to be turned on when the second auxiliary power supply is powered on and a third terminal voltage of the second auxiliary power supply control module is lower than a second value.

6. The power supply circuit according to claim 5, wherein: The power supply circuit also includes a second anti-backfeed switch module; the second anti-backfeed switch module is arranged between the second auxiliary power supply and the second auxiliary power supply control module, and the second anti-backfeed switch module is cut off when the second auxiliary power supply has no voltage.

7. The power supply circuit according to any one of claims 1 to 6, wherein: The main power control module includes: a third P-type field effect transistor, a second N-type field effect transistor, a ninth resistor, a tenth resistor and an eleventh resistor; Wherein, the drain of the third P-type field effect transistor is connected to the first end of the main power control module, and the source of the third P-type field effect transistor is connected to the second end of the main power control module; The gate of the third P-type field effect transistor is connected to the drain of the second N-type field effect transistor through the tenth resistor, and the drain of the second N-type field effect transistor is also connected to the source of the third P-type field effect transistor through the eleventh resistor; The source of the second N-type field effect transistor is grounded; the gate of the second N-type field effect transistor is connected to the first end of the ninth resistor, the first end of the ninth resistor is also connected to the drain of the third P-type field effect transistor, and the second end of the ninth resistor is grounded.

8. The power supply circuit according to any one of claims 1 to 7, wherein: The resistance value of the second resistor is greater than the resistance value of the first resistor.

9. The power supply circuit according to any one of claims 1 to 8, wherein: The primary power source comprises an output of a power adapter, and the first secondary power source comprises a battery.

10. An electronic device supporting multiple power inputs, comprising the power supply circuit according to any one of claims 1 to 9.

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