CN216904375U

CN216904375U - USB adjustable quick charging circuit

Info

Publication number: CN216904375U
Application number: CN202220548837.XU
Authority: CN
Inventors: 万亮; 卢益锋; 刘胜厚
Original assignee: Xiamen Sanan Integrated Circuit Co Ltd
Current assignee: Xiamen Sanan Integrated Circuit Co Ltd
Priority date: 2022-03-10
Filing date: 2022-03-10
Publication date: 2022-07-05
Anticipated expiration: 2032-03-10

Abstract

The application provides an adjustable quick charging circuit of USB is applied to target device, the adjustable quick charging circuit of USB includes: the device comprises a D + data pin, a D-data pin, a V + power supply pin, a V-ground wire pin, two adjusting circuits and a power supply storage circuit; the positive electrode of the power storage circuit is connected with the V + power pin, and the negative electrode of the power storage circuit is connected with the V-ground pin; the first output end of one regulating circuit is connected with the D + data pin, the first output end of the other regulating circuit is connected with the D-data pin, and the second output ends of the two regulating circuits are both connected with the V-ground wire pin.

Description

USB adjustable quick charging circuit

Technical Field

The application relates to the technical field of USB adjustable quick charging circuits, in particular to a USB adjustable quick charging circuit.

Background

With the improvement of the protocol, a Universal Serial Bus (USB) power supply scheme is no longer limited to a fixed output specification of 5V/1A, the output power of the USB power supply scheme is larger and larger, the output voltage of the USB power supply scheme is more and more diversified, the protection mechanism is more and more reliable, and the comprehensive quality of the USB power supply scheme can be compared with that of a professional linear voltage-stabilized power supply. In addition, the USB power supply equipment has low cost and is compatible with mobile communication terminal charging equipment, and power supply interfaces of a plurality of equipment use a USB interface mode. The use of the fast charging function requires the consumer to support a fast charging protocol communication. For simple equipment with only power-taking requirement and low cost, a fast charging communication module with high cost cannot be added for the fast charging function generally. At present, the method of the equipment has no communication function, and the quick charging function is abandoned and the default common power supply of the charger is used.

SUMMERY OF THE UTILITY MODEL

In view of this, an object of the present application is to provide a USB adjustable fast charging circuit, which can solve the problem that a simple electric device in the prior art cannot support a fast charging protocol.

In a first aspect, an embodiment of the present application provides an adjustable fast charging circuit for a USB, including: the power supply circuit comprises a D + data pin, a D-data pin, a V + power supply pin, a V-ground wire pin, two adjusting circuits and a power supply storage circuit; the positive electrode of the power storage circuit is connected with the V + power pin, and the negative electrode of the power storage circuit is connected with the V-ground pin; the first output end of one adjusting circuit is connected with the D + data pin, the first output end of the other adjusting circuit is connected with the D-data pin, and the second output ends of the two adjusting circuits are connected with the V-ground pin.

Optionally, the adjusting circuit includes a regulated power supply, a first voltage dividing circuit and a second voltage dividing circuit;

the positive electrode of the stabilized voltage supply is connected with the first electrode of the first voltage division circuit;

the second pole of the first voltage division circuit is connected with the first pole of the second voltage division circuit;

the negative electrode of the stabilized voltage supply, the third pole of the first voltage division circuit, the third pole of the second voltage division circuit and the second pole of the second voltage division circuit are all connected with the V-ground pin;

and the middle node of the second pole of the first voltage division circuit and the first pole of the second voltage division circuit is connected with the D + data pin or the D + data pin.

Optionally, the regulated power supply is the power storage circuit.

Optionally, the voltage range of the voltage-stabilized power supply is 3-5V.

Optionally, the first voltage dividing circuit includes a first three-port semiconductor switch, a first bias voltage, a first resistor, and a second resistor;

the first pole of the first three-port semiconductor switch is connected with the positive pole of the stabilized voltage power supply;

a first resistor is connected between a second pole of the first three-port semiconductor switch and a first pole of the second voltage division circuit, and an intermediate node between the first resistor and the first pole of the second voltage division circuit is connected with the D + data pin or the D + data pin;

a second resistor is connected between a third pole of the first three-port semiconductor switch and the anode of the first bias voltage;

and the negative electrode of the first bias voltage, the negative electrode of the stabilized voltage supply, the second pole of the second voltage division circuit and the third pole of the second voltage division circuit are connected with the V-ground pin.

Optionally, the second voltage division circuit includes a second three-port semiconductor switch, a second bias voltage, a third resistor, and a fourth resistor;

a first pole of the second three-port semiconductor switch is connected with a second pole of the first voltage division circuit, and an intermediate node of the first pole of the second three-port semiconductor switch and the second pole of the first voltage division circuit is connected with the D + data pin or the D + data pin;

the second pole of the second three-port semiconductor switch tube is connected with one end of a third resistor, and the other end of the third resistor is connected with the V-ground wire pin;

a fourth resistor is connected between a third pole of the second three-port semiconductor switch and the anode of the second bias voltage;

and the negative electrode of the second bias voltage, the negative electrode of the stabilized voltage supply and the third electrode of the first voltage division circuit are connected with the V-ground wire pin.

Optionally, the first three-port semiconductor switch is a PNP triode, the voltage value of the first bias voltage is 0.7V, the resistance value of the first resistor is 1-100 kohms, and the resistance value of the second resistor is 10-200 kohms.

Optionally, the second three-port semiconductor switch is an NPN triode, the voltage value of the second bias voltage is 0.7V, the resistance value of the third resistor is 1-100 kohms, and the resistance value of the fourth resistor is 10-200 kohms.

Optionally, the first three-port semiconductor switch is a PNP field effect transistor, the voltage value of the first bias voltage is 3V, the resistance value of the first resistor is 1 to 100 kohms, and the resistance value of the second resistor is 0 to 200 kohms.

Optionally, the second three-port semiconductor switch is an NPN field-effect transistor, the voltage value of the second bias voltage is 3V, the resistance value of the third resistor is 1 to 100 kohms, and the resistance value of the fourth resistor is 0 to 200 kohms.

In the embodiment provided by the application, the designed USB adjustable quick charging circuit is applied to simple electric equipment, so that the simple electric equipment can also support a quick charging protocol, and the quick charging of the simple electric equipment is realized.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings that are required to be used in the embodiments will be briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present application and therefore should not be considered as limiting the scope, and for those skilled in the art, other related drawings can be obtained from the drawings without inventive effort.

Fig. 1 is a schematic diagram illustrating a USB adjustable fast charging circuit according to an embodiment of the present disclosure;

fig. 2 is a schematic diagram illustrating charging of a powered device capable of being charged by a fast charging protocol in the prior art according to an embodiment of the present application;

FIG. 3 is a schematic diagram of an adjusting circuit provided by an embodiment of the present application;

fig. 4 shows a schematic diagram of a detailed adjustment circuit provided in an embodiment of the present application.

Detailed Description

In order to make the purpose, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it should be understood that the drawings in the present application are for illustrative and descriptive purposes only and are not used to limit the scope of protection of the present application. Additionally, it should be understood that the schematic drawings are not necessarily drawn to scale. The flowcharts used in this application illustrate operations implemented according to some embodiments of the present application. It should be understood that the operations of the flow diagrams may be performed out of order, and steps without logical context may be performed in reverse order or simultaneously. One skilled in the art, under the guidance of this application, may add one or more other operations to, or remove one or more operations from, the flowchart.

In addition, the described embodiments are only a part of the embodiments of the present application, and not all of the embodiments. The components of the embodiments of the present application, generally described and illustrated in the figures herein, can be arranged and designed in a wide variety of different configurations. Thus, the following detailed description of the embodiments of the present application, presented in the accompanying drawings, is not intended to limit the scope of the claimed application, but is merely representative of selected embodiments of the application. All other embodiments, which can be derived by a person skilled in the art from the embodiments of the present application without making any creative effort, shall fall within the protection scope of the present application.

To enable those skilled in the art to use the present disclosure, the following embodiments are given in conjunction with a specific application scenario, "screen backlight circuit". It will be apparent to those skilled in the art that the general principles defined herein may be applied to other embodiments and applications without departing from the spirit and scope of the application. Although the present application is described primarily in the context of a screen backlight circuit, it should be understood that this is merely one exemplary embodiment.

It should be noted that in the embodiments of the present application, the term "comprising" is used to indicate the presence of the features stated hereinafter, but does not exclude the addition of further features.

For example, as shown in fig. 2, after the electric device establishes communication with the charger, the electric device may send request information according to its actual charging specification, and the charger outputs a charging voltage and a power limit according with the charging specification in the request information after receiving the request information. However, protocol communication is realized at the present stage by a communication module with relatively high cost, and in some simple electric devices, such as children toys, table lamps, calculators, recording pens and the like, because of the limitations of cost, product size and the like, the communication module cannot be arranged in the electric devices, so that the simple electric devices can only be charged by using the common power supply of a charger, and the charging speed is relatively low.

In order to solve the above drawbacks, as shown in fig. 1, the present application provides a USB adjustable fast charging circuit, which is applied to a target device, and includes: a D + data pin, a D-data pin, a V + power pin, a V-ground pin, two adjusting circuits 101 and a power storage circuit 102; the positive electrode of the power storage circuit 102 is connected with the V + power pin, and the negative electrode of the power storage circuit 102 is connected with the V-ground pin; the first output terminal of one of the adjusting circuits 101 is connected to the D + data pin, the first output terminal of the other adjusting circuit 101 is connected to the D-data pin, and the second output terminals of both adjusting circuits 101 are connected to the V-ground pin.

The target equipment is electric equipment which is not provided with a communication module. The target equipment comprises a USB adjustable quick-charging circuit, and the target equipment is connected with a charger supporting a quick-charging protocol through the USB adjustable quick-charging circuit to realize the quick charging of the target equipment. At present, the quick-charging protocol is a relatively uniform specification, for example, USB Type a, Type B and USB Micro devices all widely adopt a QC2.0 quick-charging protocol, the quick-charging protocol reserves a simple mode without handshake communication, and as shown in table 1, different output voltages correspond to different output voltages of a D + data pin and a D-data pin. The D + data pin and the D-data pin are used for transmitting data, the D + data pin is used for sending data, the D-data pin is used for receiving data, and the D + data pin and the D-data pin can be used for outputting voltage meeting a fast charging protocol in the application. The V + power supply pin is used for receiving the voltage output by the charger. The D + data pin and the D-data pin are respectively connected with an adjusting circuit, and the D + data pin and the D-data pin send output voltage signals of the adjusting circuit to the charger, so that the charger feeds back fast charging voltage matched with the voltage signals output by the D + data pin and the D-data pin to the target device.

For example, as shown in table 1, when the voltage signal output from the D + data pin is 0.6V and the voltage signal output from the D-data pin is 0.6V, the charger feeds back a fast charging voltage of 12V to the target device.

TABLE 1

D+	D-	Output
			0.6V	0.6V	12V
3.3V	0.6V	9V
			3.3V	3.3V	20V
0.6V	GND	5V

As shown in fig. 3, the present application provides a schematic diagram of a regulating circuit, where the regulating circuit 101 includes a regulated power supply 1011, a first voltage-dividing circuit 1012 and a second voltage-dividing circuit 1013;

the positive electrode of the regulated power supply 1011 is connected to the first electrode of the first voltage dividing circuit 1012;

a second pole of the first voltage-dividing circuit 1012 is connected to a first pole of the second voltage-dividing circuit 1013;

a negative electrode of the regulated power supply 1011, a third electrode of the first voltage divider 1012, a third electrode of the second voltage divider 1013, and a second electrode of the second voltage divider 1013 are all connected to the V-ground pin;

an intermediate node between the second pole of the first voltage-dividing circuit 1012 and the first pole of the second voltage-dividing circuit 1013 is connected to the D + data pin or the D + data pin.

The voltage-stabilized power source 1011 can be a battery with a voltage value ranging from 3V to 5V, or can be a power storage circuit, the power storage circuit 102 outputs a voltage with a voltage value ranging from 3V to 5V to the first voltage-dividing circuit, and the power storage circuit 102 supplies power to an engine of a target device. In the adjusting circuit 101, the output voltage signal is adjusted by the first voltage-dividing circuit 1012 and the second voltage-dividing circuit 1013, that is, the voltage value output by the intermediate node Vout of the second pole of the first voltage-dividing circuit 1012 and the first pole of the second voltage-dividing circuit 1013, so that when the output voltage values of the D + data pin and the D + data pin are different, the voltage-dividing states of the first voltage-dividing circuit and the second voltage-dividing circuit in the adjusting circuit 101 connected to the D + data pin and the D + data pin are different.

Specifically, as shown in fig. 4, the present application provides a detailed schematic diagram of an adjusting circuit, which includes a first voltage dividing circuit 1012 and a second voltage dividing circuit 1013.

The first voltage dividing circuit 1012 comprises a first three-port semiconductor switch T1, a first bias voltage V1, a first resistor R1 and a second resistor R2;

a first pole of the first three-port semiconductor switch T1 is connected to the positive pole of the regulated power supply 1011;

a first resistor R1 is connected between the second pole of the first three-port semiconductor switch T1 and the first pole of the second voltage-dividing circuit 1013, and an intermediate node Vout between the first resistor R1 and the first pole of the second voltage-dividing circuit 1013 is connected to the D + data pin or the D + data pin;

a second resistor R2 is connected between the third pole of the first three-port semiconductor switch T1 and the anode of the first bias voltage V1;

the negative electrode of the first bias voltage V1, the negative electrode of the regulated power supply 1011, the second pole of the second voltage divider 1013, and the third pole of the second voltage divider 1013 are all connected to the V-ground pin.

The second voltage divider 1013 includes a second three-port semiconductor switch T2, a second bias voltage V2, a third resistor R3, and a fourth resistor R4;

a first pole of the second three-port semiconductor switch T2 is connected to a second pole of the first voltage divider circuit 1012, and an intermediate node Vout between the first pole of the second three-port semiconductor switch T2 and the second pole of the first voltage divider circuit 1012 is connected to the D + data pin or the D + data pin;

a second pole of the second three-port semiconductor switch T2 is connected with one end of a third resistor R3, and the other end of the third resistor R3 is connected with the V-ground pin;

a fourth resistor R4 is connected between the third pole of the second three-port semiconductor switch T2 and the anode of the second bias voltage V2;

the negative electrode of the second bias voltage V2 and the negative electrode of the regulated power supply 1011 and the third electrode of the first voltage divider 1012 are both connected to the V-ground pin.

The first three-port semiconductor switch T1 is a PNP triode, the voltage value of the first bias voltage V1 is 0.7V, the resistance value of the first resistor R1 is 1-100 kohms, and the resistance value of the second resistor R2 is 10-200 kohms. The voltage is controlled by switching on and off the PNP triode, for example, the voltage of the stabilized voltage supply is 3V, and when the PNP triode is switched on, the switching-on voltage is 0-2.3V; when the PNP triode is turned off, the turn-off voltage is 2.3V-3V.

The second three-port semiconductor switch T2 is an NPN transistor, the voltage value of the second bias voltage V2 is 0.7V, the resistance value of the third resistor R3 is 1-100 kohms, and the resistance value of the fourth resistor R4 is 10-200 kohms. The control of the voltage is realized by switching on and off the NPN triode, for example, the voltage of the voltage-stabilized power supply is 3V, and when the NPN triode is switched on, the switching-on voltage is 0.7-3V; when the NPN triode is turned off, the turn-off voltage is 0-0.7V.

When the three-port semiconductor switch is a transistor, the transistor is operated by current, so that a current signal should be input to the base of the transistor, and a resistor (i.e., the second resistor R2 or the fourth resistor R4) needs to be arranged between the bias voltage and the base of the transistor. For the resistance requirement of the second resistor R2 or the fourth resistor R4, it needs to be determined according to the performance of the transistor, for example, if the amplification capability of the transistor is small, the input current needs to be large, so the resistance of the second resistor R2 or the fourth resistor R4 will be small.

In addition to the transistor, the fet is also a three-port semiconductor switch, and the above-described regulator circuit can be implemented using the fet as well. However, the transistor is controlled by current and the fet is controlled by voltage, so that when the fet is applied to the regulator circuit, the value requirements of the electronic components in the first voltage divider circuit and the second voltage divider circuit in the regulator circuit are different.

When the first three-port semiconductor switch T1 is a PNP fet, the voltage value of the first bias voltage V1 is 3V, the resistance value of the first resistor R1 is 1-100 kohms, and the resistance value of the second resistor R2 is 0-200 kohms. The voltage is controlled by switching on and off the PNP field effect transistor, for example, the voltage of the stabilized voltage supply is 5V, and when the PNP field effect transistor is switched on, the switching-on voltage is 0-2V; when the PNP field effect transistor is turned off, the turn-off voltage is 2V-5V.

The second three-port semiconductor switch T2 is an NPN field-effect transistor, the voltage value of the second bias voltage V2 is 3V, the resistance value of the third resistor R3 is 1-100 kohms, and the resistance value of the fourth resistor R2 is 0-200 kohms. The control of the voltage is realized by switching on and off the NPN field effect transistor, for example, the voltage of the voltage-stabilized power supply is 5V, and when the NPN field effect transistor is switched on, the switching-on voltage is 3-5V; when the NPN field effect transistor is turned off, the turn-off voltage is 0-3V.

When the three-port semiconductor switch is a field effect transistor, the field effect transistor is controlled by voltage, so that a voltage signal is input to the base of the field effect transistor, and a resistor (namely, the second resistor R2 or the fourth resistor R4) can be omitted between the bias voltage and the base of the field effect transistor. However, there may be an oscillation loop in the circuit, and in order to reduce oscillation in the circuit, a resistance is provided between the bias voltage and the base of the field effect transistor, thereby reducing a damping protection circuit of the oscillation loop. The second resistor R2 or the fourth resistor R4 is only used for protecting the circuit, so the resistance requirement is generally smaller, i.e. 0-200 ohms.

In the above-mentioned adjusting circuit 101, the first resistor R1 and the third resistor R3 divide the voltage of the regulated power supply together, so that the resistance values of the first resistor R1 and the third resistor R3 are generally large in order to achieve the target output voltage, and therefore, the value ranges of the resistance values of the first resistor R1 and the third resistor R3 are 1 to 100 kilo ohms, and the resistance value of the first resistor R1 and the resistance value of the third resistor R3 are set according to actual requirements. In the present application, the adjusting circuit 101 can output three different voltage signals, which are 0V, 0.6V and 3.3V respectively, by adjusting the first three-port semiconductor switch T1 and the second three-port semiconductor switch T2 and adjusting the resistance value of the first resistor R1 and the resistance value of the third resistor R3.

Since the first three-port semiconductor switch T1 and the second three-port semiconductor switch T2 in the adjusting circuit 101 may need to be pulled up or pulled down simultaneously, the directions of the emitters of the two three-port semiconductor switches need to be consistent, the N pole of the three-port semiconductor switch needs to be connected to the ground, and the P pole of the three-port semiconductor switch needs to be connected to the non-ground, so to sum up, the first three-port semiconductor switch T1 is a PNP transistor or fet, and the second three-port semiconductor switch T2 is an NPN transistor or fet.

Although the three-port semiconductor switch in the adjusting circuit 101 may be a triode or a field effect transistor, the three-port semiconductor switch in the adjusting circuit 101 is preferably a triode in consideration of the factors of production cost, operation accuracy and the like, because the scheme of the present application is applied to a target device with a 3V-5V regulated power supply. Because the bias voltage of the field effect transistor is 3V and is very close to the voltage value of the voltage-stabilized power supply, the field effect transistor is easily incompletely turned off when being turned off, and further the operation accuracy is low. And the cost of the field effect transistor is relatively high.

However, the field effect transistor has the characteristics of low power consumption, good performance and high response speed, so the field effect transistor can be generally applied to target equipment with a larger voltage value of a voltage-stabilized power supply.

The USB adjustable quick charging circuit is set when target equipment leaves factory, so that quick charging voltage matched with the target equipment is also preset, and therefore all parameters of the adjusting circuit in the USB adjustable quick charging circuit need to be set when the target equipment leaves factory. The resistance values of the first resistor R1, the second resistor R2, the third resistor R3 and the fourth resistor R4 are determined according to the voltage value of the regulated power supply, for example, when the regulated power supply is 3.3V, the resistance values of the first resistor R1, the second resistor R2, the third resistor R3 and the fourth resistor R4 may be different from the resistance values of the first resistor R1, the second resistor R2, the third resistor R3 and the fourth resistor R4 when the regulated power supply is 5V.

For an example of a certain embodiment, briefly introducing the USB adjustable fast charging circuit provided in the present application, when the regulated power supply is 3.3V, the voltage values of V1 and V2 are 0.7V, the resistance value of the first resistor R1 is 5.1 kilo-ohm, the resistance value of the second resistor R2 is 56 kilo-ohm, the resistance value of the third resistor R3 is 1 kilo-ohm, and the resistance value of the fourth resistor R4 is 56 kilo-ohm, and in different switching states of the first triode T1 and the second triode T2, the output voltages of the adjusting circuit are respectively as follows:

when the first triode T1 is turned on and the second triode T2 is turned off, the first resistor R1, the third resistor R3 and the first triode T1 are grounded, and the node Vout is grounded for output;

when the first triode T1 is turned off and the second triode T2 is turned on, the first resistor R1, the third resistor R3 and the second triode T2 are connected to the regulated power supply 1011, and the node Vout outputs 3.3V;

when the first transistor T1 and the second transistor T2 are both turned on, the Vout node output power supply of 0.6V can be realized based on the resistances of the first resistor R1 and the third resistor R3.

Based on the USB adjustable quick charging circuit provided by the application, the target equipment without the communication module can be matched with the charger protocol supporting the quick charging protocol under the condition that data transmission is not needed, so that the target equipment and the charger supporting the quick charging protocol can be quickly charged without holding hands for communication, and the charging efficiency is improved.

It can be clearly understood by those skilled in the art that, for convenience and brevity of description, the specific working processes of the system and the apparatus described above may refer to corresponding processes in the method embodiments, and are not described in detail in this application. In the several embodiments provided in the present application, it should be understood that the disclosed system, apparatus and method may be implemented in other ways. The above-described apparatus embodiments are merely illustrative, and for example, the division of the modules is merely a logical division, and there may be other divisions in actual implementation, and for example, a plurality of modules or components may be combined or integrated into another system, or some features may be omitted, or not executed. In addition, the shown or discussed mutual coupling or direct coupling or communication connection may be an indirect coupling or communication connection of devices or modules through some communication interfaces, and may be in an electrical, mechanical or other form.

The modules described as separate parts may or may not be physically separate, and parts displayed as modules may or may not be physical units, may be located in one place, or may be distributed on a plurality of network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of the embodiment.

In addition, functional units in the embodiments of the present application may be integrated into one processing unit, or each unit may exist alone physically, or two or more units are integrated into one unit.

The functions, if implemented in the form of software functional units and sold or used as a stand-alone product, may be stored in a non-volatile computer-readable storage medium executable by a processor. Based on such understanding, the technical solution of the present application or portions thereof that substantially contribute to the prior art may be embodied in the form of a software product stored in a storage medium and including instructions for causing a computer device (which may be a personal computer, a server, or a network device) to execute all or part of the steps of the method according to the embodiments of the present application. And the aforementioned storage medium includes: various media capable of storing program codes, such as a U disk, a removable hard disk, a ROM, a RAM, a magnetic disk, or an optical disk.

The above description is only for the specific embodiments of the present application, but the scope of the present application is not limited thereto, and any person skilled in the art can easily conceive of the changes or substitutions within the technical scope of the present application, and shall be covered by the scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims

1. The utility model provides a USB adjustable fill circuit soon which characterized in that, is applied to the target device, USB adjustable fill circuit includes soon: the power supply circuit comprises a D + data pin, a D-data pin, a V + power supply pin, a V-ground wire pin, two adjusting circuits and a power supply storage circuit; the positive electrode of the power storage circuit is connected with the V + power pin, and the negative electrode of the power storage circuit is connected with the V-ground pin; the first output end of one adjusting circuit is connected with the D + data pin, the first output end of the other adjusting circuit is connected with the D-data pin, and the second output ends of the two adjusting circuits are connected with the V-ground pin.

2. The USB adjustable fast charging circuit according to claim 1, wherein the adjusting circuit comprises a regulated power supply, a first voltage dividing circuit and a second voltage dividing circuit;

a second pole of the first voltage division circuit is connected with a first pole of the second voltage division circuit;

3. The USB adjustable fast charging circuit of claim 2, wherein the regulated power supply is the power storage circuit.

4. The USB adjustable fast charging circuit according to claim 2, wherein the voltage of the regulated power supply is in a range of 3-5V.

5. The USB adjustable fast charging circuit according to claim 2, wherein the first voltage divider circuit comprises a first three-port semiconductor switch, a first bias voltage, a first resistor and a second resistor;

6. The USB adjustable fast charging circuit according to claim 2, wherein the second voltage divider circuit comprises a second three-port semiconductor switch, a second bias voltage, a third resistor, and a fourth resistor;

a second pole of the second three-port semiconductor switch is connected with one end of a third resistor, and the other end of the third resistor is connected with the V-ground wire pin;

7. The USB adjustable fast charging circuit according to claim 5, wherein the first three-port semiconductor switch is a PNP triode, the voltage value of the first bias voltage is 0.7V, the resistance value of the first resistor is 1-100 kilo ohms, and the resistance value of the second resistor is 10-200 kilo ohms.

8. The USB adjustable fast charging circuit according to claim 6, wherein the second three-port semiconductor switch is an NPN transistor, the voltage value of the second bias voltage is 0.7V, the resistance value of the third resistor is 1-100 kilo ohms, and the resistance value of the fourth resistor is 10-200 kilo ohms.

9. The USB adjustable quick charging circuit according to claim 5, wherein the first three-port semiconductor switch is a PNP field effect transistor, the voltage value of the first bias voltage is 3V, the resistance value of the first resistor is 1-100 kilo ohms, and the resistance value of the second resistor is 0-200 ohms.

10. The USB adjustable fast charging circuit according to claim 6, wherein the second three-port semiconductor switch is an NPN field effect transistor, the voltage value of the second bias voltage is 3V, the resistance value of the third resistor is 1-100 kilo ohms, and the resistance value of the fourth resistor is 0-200 ohms.