Power switching circuits and electronic devices

Abstract

The present invention provides a power switching circuit and electronic device. The power switching circuit includes a first voltage drop conduction module and a second voltage drop conduction module. The first end of the first voltage drop conduction module is connected to the first end of the second voltage drop conduction module, the second end of the first voltage drop conduction module is connected to the first power input end, and the third end of the first voltage drop conduction module is used to connect to the circuit output end. The first voltage drop conduction module is used to conduct when the voltage at the second end is greater than the voltage at the first end, and to cut off when the voltage at the second end is less than the voltage at the first end. The second end of the second voltage drop conduction module is connected to the second power input end, and the third end of the second voltage drop conduction module is used to connect to the circuit output end. The voltage at the second power input end is greater than the sum of the voltage at the first power input end and the voltage drop voltage. Mutual interference between the two power supplies is avoided, and when the two power supplies are connected at the same time, the first power input end is automatically cut off, thereby determining the priority of the power supply.

Description

Technical Field

[0001] The present invention relates to the technical field of power switching control, and in particular to a power switching circuit and electronic equipment. Background Art

[0002] With the widespread use of various electronic devices, electronic devices often require dual power supplies to meet user needs. Dual power supplies refer to the battery on the electronic device and the power supply connected to the USB (Universal Serial Bus) interface.

[0003] Electronic devices with dual power supplies only require one power source to provide power. Therefore, automatic power switching is required to protect the battery and ensure compatibility between the controller and the device. For example, when no USB power source is plugged in, the battery powers the controller. When a USB power source is plugged in, the USB power source directly powers the controller, cutting off the battery and minimizing battery loss.

[0004] However, current electronic devices typically use two switches to switch power. For example, each power source is controlled by a switch. By turning the two switches on and off, one power source is switched on and the other is switched off. However, this traditional power switching method suffers from interference between the two power sources and an inability to determine power supply priority, resulting in inflexible power switching. Summary of the Invention

[0005] Based on this, it is necessary to provide a power switching circuit and electronic equipment to address the above technical problems.

[0006] A power switching circuit includes: a first power input terminal, a second power input terminal, a first voltage drop conduction module, and a second voltage drop conduction module;

[0007] The first end of the first voltage drop conduction module is connected to the first end of the second voltage drop conduction module, the second end of the first voltage drop conduction module is connected to the first power input end, and the third end of the first voltage drop conduction module is used to be connected to the circuit output end, and the second end and the third end of the first voltage drop conduction module are used to conduct when the voltage of the second end of the first voltage drop conduction module is greater than the voltage of the first end of the first voltage drop conduction module, and to be cut off when the voltage of the second end of the first voltage drop conduction module is less than the voltage of the first end of the first voltage drop conduction module;

[0008] The second end of the second voltage drop conduction module is connected to the second power input end, and the third end of the second voltage drop conduction module is used to be connected to the circuit output end. The second end and the third end of the second voltage drop conduction module are used to conduct when the voltage of the second end of the second voltage drop conduction module is greater than the voltage of the first end of the second voltage drop conduction module, and to cut off when the voltage of the second end of the second voltage drop conduction module is less than the voltage of the first end of the second voltage drop conduction module.

[0009] The voltage difference between the second end and the first end of the second voltage drop conduction module is a voltage drop voltage, and the voltage of the second power input end is greater than the sum of the voltage of the first power input end and the voltage drop voltage.

[0010] In one embodiment, a first resistor is further included, and the first end of the second voltage drop conduction module is grounded through the first resistor.

[0011] In one embodiment, a second resistor is further included, and the first end of the first voltage drop conduction module is connected to the first end of the second voltage drop conduction module through the second resistor.

[0012] In one embodiment, the first voltage drop conduction module includes a PNP transistor Q1.

[0013] In one embodiment, the first voltage drop conduction module includes a transistor Q1, the first end of the first voltage drop conduction module is the base of the transistor Q1, the second end of the first voltage drop conduction module is the emitter of the transistor Q1, and the third end of the first voltage drop conduction module is the collector of the transistor Q1.

[0014] In one embodiment, the second voltage drop conduction module includes a PNP transistor Q2.

[0015] In one embodiment, the first end of the second voltage drop conduction module is the base of the transistor Q2, the second end of the second voltage drop conduction module is the emitter of the transistor Q2, and the third end of the second voltage drop conduction module is the collector of the transistor Q2.

[0016] In one embodiment, the first power input terminal is used to connect to a battery device, and the second power input terminal is used to connect to a USB device.

[0017] In one embodiment, the first voltage drop conduction module includes an NPN transistor, and the second voltage drop conduction module includes an NPN transistor.

[0018] An electronic device includes the power switching circuit described in any one of the above embodiments.

[0019] In the power switching circuit and electronic device, since the voltage at the second power input terminal is greater than the sum of the voltage at the first power input terminal and the voltage drop voltage, when the first power input terminal and the second power input terminal simultaneously input voltage, the second terminal and the third terminal of the second voltage drop conduction module are turned on, so that the power supply at the second power input terminal supplies power to the circuit output terminal. Since the voltage at the second terminal of the first voltage drop conduction module is less than the voltage at the first terminal at this time, the first voltage drop conduction module is turned off. When the first power input terminal inputs a voltage and the second power input terminal does not input a voltage, the first voltage drop conduction module is turned on, and the power supply at the first power input terminal supplies power to the circuit output terminal. When the second power input terminal inputs a voltage and the first power input terminal does not input a voltage, the second voltage drop conduction module is turned on, and the power supply at the second power input terminal supplies power to the circuit output terminal. Thus, switching between the two power supplies is achieved. Due to the unidirectional conduction characteristics of the first and second voltage drop conduction modules, mutual interference between the two power supplies is avoided. When the two power supplies are connected simultaneously, the first power input terminal is automatically cut off, thereby determining the power supply priority and making power switching more flexible. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 is a schematic diagram of a circuit principle of a power switching circuit in one embodiment;

[0021] Figure 2 FIG. 4 is a schematic diagram of a circuit principle of a power switching circuit in another embodiment. DETAILED DESCRIPTION

[0022] In order to make the purpose, technical solutions and advantages of this application more clear, the following further describes this application in detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain this application and are not intended to limit this application.

[0023] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it may be directly on the other element or there may be an intermediate element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be an intermediate element. The terms "vertical," "horizontal," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only implementation methods.

[0024] Example 1

[0025] In this embodiment, Figure 1 As shown, a power switching circuit is provided, including: a first power input terminal IN1, a second power input terminal IN2, a first voltage drop conduction module and a second voltage drop conduction module.

[0026] The first end of the first voltage drop conduction module is connected to the first end of the second voltage drop conduction module, the second end of the first voltage drop conduction module is connected to the first power input terminal IN1, and the third end of the first voltage drop conduction module is used to be connected to the circuit output terminal OUT. The second end and the third end of the first voltage drop conduction module are used to conduct when the voltage of the second end of the first voltage drop conduction module is greater than the voltage of the first end of the first voltage drop conduction module, and to be cut off when the voltage of the second end of the first voltage drop conduction module is less than the voltage of the first end of the first voltage drop conduction module.

[0027] The second end of the second voltage drop conduction module is connected to the second power supply input terminal IN2, and the third end of the second voltage drop conduction module is used to be connected to the circuit output terminal OUT. The second end and the third end of the second voltage drop conduction module are used to conduct when the voltage of the second end of the second voltage drop conduction module is greater than the voltage of the first end of the second voltage drop conduction module, and to be cut off when the voltage of the second end of the second voltage drop conduction module is less than the voltage of the first end of the second voltage drop conduction module.

[0028] The voltage difference between the second end and the first end of the second voltage drop conduction module is a voltage drop voltage, and the voltage of the second power input terminal IN2 is greater than the sum of the voltage of the first power input terminal IN1 and the voltage drop voltage.

[0029] In this embodiment, when the voltage of the second end of the first voltage drop conduction module is greater than the voltage of the first end, the second end and the third end of the first voltage drop conduction module are conductive; when the voltage of the second end of the second voltage drop conduction module is greater than the voltage of the first end, the second end and the third end of the second voltage drop conduction module are conductive.

[0030] There is a voltage drop between the second end and the first end of the second voltage drop conduction module, and the first end of the second voltage drop conduction module is connected to the first end of the first voltage drop conduction module, so that the voltage of the first end of the first voltage drop conduction module is equal to the voltage of the first end of the second voltage drop conduction module, and the voltage of the second end of the second voltage drop conduction module is equal to the voltage of the second power input terminal IN2.

[0031] Therefore, when the first power input terminal IN1 and the second power input terminal IN2 input voltages at the same time, since the voltage of the second power input terminal IN2 is greater than the sum of the voltage of the first power input terminal IN1 and the voltage drop voltage, the voltage of the first end of the first voltage drop conduction module is greater than the voltage of the second end of the first voltage drop conduction module, and the second end and the third end of the first voltage drop conduction module are cut off, while the voltage of the second power input terminal IN2, that is, the voltage of the second end of the second voltage drop conduction module, is greater than the voltage of the first end of the second voltage drop conduction module. The second end and the third end of the second voltage drop conduction module are connected, so that the power supply of the second power input terminal IN2 supplies power to the circuit output terminal OUT. In this way, even if the first power input terminal IN1 and the second power input terminal IN2 input voltages at the same time, the second power input terminal IN2 can be automatically selected as the power supply without the need for manual control or chip control of power supply priority, making the control of priority power supply more flexible, more efficient, and lower in cost.

[0032] When a voltage is input to the first power input terminal IN1 and no voltage is input to the second power input terminal IN2, the voltage at the first terminal of the first voltage drop conduction module is equal to zero. Since the voltage at the second terminal of the first voltage drop conduction module is greater than the voltage at the first terminal, the second terminal and the third terminal of the first voltage drop conduction module are conductive, and the power supply of the first power input terminal IN1 supplies power to the circuit output terminal OUT.

[0033] When a voltage is input to the second power input terminal IN2 and no voltage is input to the first power input terminal IN1, since the voltage at the second end of the second voltage drop conduction module is greater than the voltage at the first end, the second end and the third end of the second voltage drop conduction module are turned on, and the power supply of the second power input terminal IN2 supplies power to the circuit output terminal OUT.

[0034] In the above process, switching between the two power supplies is achieved. Due to the unidirectional conduction characteristics of the first voltage drop conduction module and the second voltage drop conduction module, mutual interference between the two power supplies is avoided. In addition, when the two power supplies are connected at the same time, the first power supply input terminal is automatically cut off, thereby determining the priority of the power supply and making the power supply switching more flexible.

[0035] In one embodiment, Figure 1 As shown, the power switching circuit further includes a first resistor R1, and the first end of the second voltage drop conduction module is grounded through the first resistor R1. In this embodiment, the first resistor R1 limits the current passing through the first end of the second voltage drop conduction module to protect the second voltage drop conduction module.

[0036] In one embodiment, Figure 1As shown, the power switching circuit further includes a second resistor R2, through which the first end of the first voltage drop conduction module is connected to the first end of the second voltage drop conduction module. In this embodiment, the first resistor R2 limits the current passing through the first end of the first voltage drop conduction module, thereby protecting the first voltage drop conduction module.

[0037] In one embodiment, Figure 2 As shown, the first voltage drop conduction module includes a PNP transistor Q1. In this embodiment, the first voltage drop conduction module includes the transistor Q1, the first end of the first voltage drop conduction module is the base of the transistor Q1, the second end of the first voltage drop conduction module is the emitter of the transistor Q1, and the third end of the first voltage drop conduction module is the collector of the transistor Q1.

[0038] In one embodiment, Figure 2 As shown, the second voltage drop conduction module includes a PNP-type transistor Q2. In this embodiment, the first end of the second voltage drop conduction module is the base of the transistor Q2, the second end of the second voltage drop conduction module is the emitter of the transistor Q2, and the third end of the second voltage drop conduction module is the collector of the transistor Q2.

[0039] In this embodiment, the power supply voltage connected to the first power input terminal is +3.3V, the power supply voltage connected to the second power input terminal is +5V, the emitter of the transistor Q1 is connected to the first power input terminal, the base of the transistor Q1 is connected to the first end of the second resistor R2, the second end of the second resistor R2 is connected to the base of the transistor Q2, the collector of the transistor Q1 is connected to the circuit output terminal, the emitter of the transistor Q2 is connected to the second power input terminal, the base of the transistor Q2 is connected to the first end of the first resistor R1, the second end of the first resistor R1 is used for grounding, and the collector of the transistor Q2 is connected to the circuit output terminal.

[0040] In this embodiment, when transistor Q2 is a silicon transistor, based on its forward voltage drop of 0.7V, the relationship between the voltage Uusb at the second power input terminal and the voltage Ubat at the first power input terminal is: Uusb>(Ubat+0.7V). When transistor Q2 is a germanium transistor, based on its forward voltage drop of 0.2V, the relationship between the voltage Uusb at the second power input terminal and the voltage Ubat at the first power input terminal is: Uusb>(Ubat+0.2V).

[0041] In this way, since the voltage of the USB device power supply is always greater than the sum of the voltage of the battery power supply and the conduction voltage drop of the transistor Q2, when the USB device power supply and the battery power supply are connected at the same time, the USB device power supply can be automatically selected as the power supply.

[0042] In one embodiment, the first power input is connected to a battery device, and the second power input is connected to a USB (Universal Serial Bus) device. In this embodiment, the first power input is connected to a battery device, i.e., the power input to the first power input is a battery, and the second power input is connected to a USB device, i.e., the power input to the second power input is a USB device power supply. The USB device power supply can be a power bank, a USB power output port of a computer device, or a transformer-transformed mains power supply, which are not listed in this embodiment.

[0043] In this embodiment, the power voltage of the first power input terminal is Ubat, and the power voltage of the second power input terminal is Uusb. Thus, when the first power input terminal and the second power input terminal are connected to a battery and a USB device power supply, respectively, transistor Q1 is turned off and transistor Q2 is turned on, and the USB device power supply supplies power to the circuit output terminal. When the first power input terminal is connected to a battery power supply and the second power input terminal is not connected to a USB device power supply, transistor Q1 is turned on and transistor Q2 is turned off, and the battery power supply supplies power to the circuit output terminal. When the first power input terminal is not connected to a battery power supply and the second power input terminal is connected to a USB device power supply, transistor Q2 is turned on and transistor Q1 is turned off, and the USB device power supply supplies power to the circuit output terminal. Through the above process, switching between battery power and USB device power is achieved. Due to the unidirectional conduction characteristics of transistors Q1 and Q2, mutual interference between the two power supplies is avoided. Furthermore, when both power supplies are connected simultaneously, the first power input terminal is automatically cut off, thereby determining the power supply priority and making power switching more flexible.

[0044] In other embodiments, the first voltage drop conduction module includes an NPN transistor, and the second voltage drop conduction module includes an NPN transistor.

[0045] It should be understood that in the above embodiment, the PNP transistor is described in detail. Those skilled in the art will know that the PNP transistor can be replaced by an NPN transistor, and the corresponding circuit structure can be adapted to adapt to the NPN transistor. This is not described in detail in this embodiment.

[0046] In one embodiment, the power switching circuit includes a transistor Q1, a transistor Q2, a resistor R1, and a resistor R2, wherein:

[0047] +3.3 (battery) is connected to pin 2 of PNP transistor Q1;

[0048] +5V (USB) power supply is connected to pin 2 of PNP transistor Q2;

[0049] Pin 1 of the PNP transistor Q1 is connected to pin 2 of R2;

[0050] The 3-pin output of the PNP transistor Q1 is OUT_+3.3V;

[0051] Pin 1 of the PNP transistor Q2 is connected to pin 1 of R2 and pin 2 of R1, and pin 1 of R2 is connected to GND;

[0052] Pin 3 of the PNP transistor Q2 outputs OUT_+5V;

[0053] Function of each component:

[0054] PNP transistor Q1: controls output OUT_+5V;

[0055] PNP transistor Q2: controls the output OUT_+3.3V and also plays the role of power supply device priority selection;

[0056] Resistor R1: limits the current passing through the base of PNP transistor Q2 and protects PNP transistor Q2;

[0057] Resistor R2: limits the current passing through the base of PNP transistor Q1 and protects PNP transistor Q1;

[0058] The power supply voltage of the USB device is greater than the power supply voltage of the low-voltage power supply device (battery) plus the voltage drop between pins 2 (emitter) and 1 (base) when PNP transistor Q2 is on. For PNP transistor Q2, assuming a silicon transistor on-state voltage drop of 0.7V, Uusb > (Ubat + 0.7V). For PNP transistor Q2, assuming a germanium transistor on-state voltage drop of 0.2V, Uusb > (Ubat + 0.2V).

[0059] When the USB device (+5V) and battery device (+3.3V) power supplies are input at the same time, the voltage between pin 2 and pin 1 of the PNP transistor Q2 is at a high level (the voltage between pin 2 and pin 1 of the PNP transistor Q2, that is, Ube, is greater than the conduction voltage of the tube, which can be calculated as 0.7V for silicon tubes and 0.2V for germanium tubes). The PNP transistor Q2 is turned on, and pin 3 of the PNP transistor Q2 outputs the OUT_+5V voltage. At the same time, the voltage of pin 2 of PNP transistor Q1 (calculated as 3.3V for battery device) to pin 1 (PNP transistor Q2 is turned on, and the silicon tube conduction voltage drop Ube is 0.7V, so the voltage of pin 1 of PNP transistor Q2 is about 4.3V) is low (the voltage of pin 2 to pin 1 of PNP transistor Q1, that is, Ube is less than the conduction voltage of the tube, the silicon tube can be calculated as 0.7V, and the germanium tube can be calculated as 0.2V), causing PNP transistor Q1 to be cut off and unable to conduct. Therefore, the dual device power supply automatically switches to the USB power device after passing through the circuit to provide power OUT_+5V for the controller, and disconnects the battery device power supply circuit.

[0060] When only the USB device (+5V) power supply is input, the voltage between pin 2 and pin 1 of the PNP transistor Q2 is high (the voltage between pin 2 and pin 1 of the PNP transistor Q2, that is, Ube, is greater than the conduction voltage of the tube, which can be calculated as 0.7V for silicon tubes and 0.2V for germanium tubes). The PNP transistor Q2 is turned on, and pin 3 of the PNP transistor Q2 outputs the OUT_+5V voltage. At the same time, the voltage between pin 2 and pin 1 of PNP transistor Q1 (PNP transistor Q2 is turned on, and according to the silicon tube conduction voltage drop Ube of 0.7V, the voltage between pin 1 of PNP transistor Q2 is about 4.3V) is at a low level (the voltage between pin 2 and pin 1 of PNP transistor Q1, that is, Ube is less than the conduction voltage of the tube, which can be calculated as 0.7V for silicon tube and 0.2V for germanium tube), causing PNP transistor Q1 to be cut off and unable to conduct. Therefore, the USB device provides power OUT_+5V for the controller.

[0061] The battery device uses a (+3.3V) power supply. The voltage between pin 2 and pin 1 of the PNP transistor Q1 is high (the voltage between pin 2 and pin 1 of the PNP transistor Q1, that is, Ube, is greater than the conduction voltage of the tube. The silicon tube can be calculated as 0.7V, and the germanium tube can be calculated as 0.2V). The PNP transistor Q1 is turned on, and pin 3 of the PNP transistor Q1 outputs the OUT_+3.3V voltage. At the same time, the voltage between pin 2 and pin 1 of PNP transistor Q2 (PNP transistor Q1 is turned on, and according to the silicon tube conduction voltage drop Ube of 0.7V, the voltage between pin 1 of PNP transistor Q1 is about 2.6V) is low (the voltage between pin 2 and pin 1 of PNP transistor Q2, that is, Ube is less than the conduction voltage of the tube, which can be calculated as 0.7V for silicon tube and 0.2V for germanium tube), causing PNP transistor Q2 to be cut off and unable to conduct. Therefore, the battery device provides power OUT_+3.3V to the controller.

[0062] Table 1 Logic table of output voltage corresponding to power supply

[0063] power supply Q1 status Q2 status OUT USB device Deadline conduction OUT_+5V Battery Equipment conduction Deadline OUT_+3.3V USB Device & Battery Device Deadline conduction OUT_+5V

[0064] In one embodiment, an electronic device is provided, comprising the power switching circuit described in any one of the above embodiments.

[0065] In the power switching circuit and electronic device, since the voltage at the second power input terminal is greater than the sum of the voltage at the first power input terminal and the voltage drop voltage, when the first power input terminal and the second power input terminal simultaneously input voltage, the second terminal and the third terminal of the second voltage drop conduction module are turned on, so that the power supply at the second power input terminal supplies power to the circuit output terminal. Since the voltage at the second terminal of the first voltage drop conduction module is less than the voltage at the first terminal at this time, the first voltage drop conduction module is turned off. When the first power input terminal inputs a voltage and the second power input terminal does not input a voltage, the first voltage drop conduction module is turned on, and the power supply at the first power input terminal supplies power to the circuit output terminal. When the second power input terminal inputs a voltage and the first power input terminal does not input a voltage, the second voltage drop conduction module is turned on, and the power supply at the second power input terminal supplies power to the circuit output terminal. Thus, switching between the two power supplies is achieved. Due to the unidirectional conduction characteristics of the first and second voltage drop conduction modules, mutual interference between the two power supplies is avoided. When the two power supplies are connected simultaneously, the first power input terminal is automatically cut off, thereby determining the power supply priority and making power switching more flexible.

[0066] For example, the electronic device is a mobile phone. When the mobile phone is not connected to an external USB power supply, the mobile phone is powered by a battery. When the mobile phone is connected to an external USB power supply, the power supply is switched to the USB power supply and the battery power supply is stopped.

[0067] The technical features of the above embodiments can be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0068] The above-described embodiments merely represent several implementation methods of the present application. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that a person skilled in the art could make various modifications and improvements without departing from the spirit of the present application, all of which fall within the scope of protection of the present application. Therefore, the scope of protection of the present patent application shall be determined by the appended claims.

Claims

1. A power switching circuit, characterized in that: include: A first power input terminal, a second power input terminal, a first voltage drop conduction module, and a second voltage drop conduction module; The first end of the first voltage drop conduction module is connected to the first end of the second voltage drop conduction module, the second end of the first voltage drop conduction module is connected to the first power input end, and the third end of the first voltage drop conduction module is used to be connected to the circuit output end, and the second end and the third end of the first voltage drop conduction module are used to conduct when the voltage of the second end of the first voltage drop conduction module is greater than the voltage of the first end of the first voltage drop conduction module, and to be cut off when the voltage of the second end of the first voltage drop conduction module is less than the voltage of the first end of the first voltage drop conduction module; The second end of the second voltage drop conduction module is connected to the second power input end, and the third end of the second voltage drop conduction module is used to be connected to the circuit output end. The second end and the third end of the second voltage drop conduction module are used to conduct when the voltage of the second end of the second voltage drop conduction module is greater than the voltage of the first end of the second voltage drop conduction module, and to cut off when the voltage of the second end of the second voltage drop conduction module is less than the voltage of the first end of the second voltage drop conduction module. The voltage difference between the second terminal and the first terminal of the second voltage drop conduction module is a voltage drop voltage, and the voltage of the second power input terminal is greater than the sum of the voltage of the first power input terminal and the voltage drop voltage; It also includes a first resistor, and the first end of the second voltage drop conduction module is grounded through the first resistor; A second resistor is also included, and the first end of the first voltage drop conduction module is connected to the first end of the second voltage drop conduction module through the second resistor.

2. The power switching circuit according to claim 1, wherein: The first voltage drop conduction module includes a PNP transistor Q1.

3. The power switching circuit according to claim 2, wherein: The first end of the first voltage drop conduction module is the base of the transistor Q1 , the second end of the first voltage drop conduction module is the emitter of the transistor Q1 , and the third end of the first voltage drop conduction module is the collector of the transistor Q1 .

4. The power switching circuit according to claim 1, wherein: The second voltage drop conduction module includes a PNP transistor Q2.

5. The power switching circuit according to claim 4, wherein: The first end of the second voltage drop conduction module is the base of the transistor Q2 , the second end of the second voltage drop conduction module is the emitter of the transistor Q2 , and the third end of the second voltage drop conduction module is the collector of the transistor Q2 .

6. The power switching circuit according to any one of claims 1 to 5, characterized in that: The first power input terminal is used to connect to a battery device, and the second power input terminal is used to connect to a USB device.

7. The power switching circuit according to claim 1, wherein: The first voltage drop conduction module includes an NPN transistor, and the second voltage drop conduction module includes an NPN transistor.

8. An electronic device, characterized in that: The invention comprises the power switching circuit described in any one of claims 1 to 7.

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