WO2020103474A1 - Charging circuit and charging system - Google Patents

Abstract

The present invention relates to the technical field of batteries, and discloses a charging circuit and a charging system. The charging circuit comprises: a voltage input terminal, a first voltage output terminal, a second voltage output terminal, a buck-boost circuit, and a buck circuit. The buck-boost circuit is used for receiving and adjusting an input voltage inputted by the voltage input terminal to obtain a first adjusted voltage, and outputting the first adjusted voltage to the first voltage output terminal, in order to output a first output voltage by means of the first voltage output terminal to charge a battery; the buck circuit is used for receiving and adjusting the first adjusted voltage inputted by the buck-boost circuit to obtain a second adjusted voltage, and outputting the second adjusted voltage to the second voltage output terminal, in order to output a second output voltage by means of the second voltage output terminal to charge an electric device. The charging circuit provided in the embodiments of the present invention can adapt to the input voltages of different charging apparatuses, so that different charging apparatuses can meet battery charging requirements.

Description

Charging circuit and charging system

Related applications cross reference

The application requires the priority of the Chinese patent application filed on November 21, 2018, with the application number 201811391484.1 and the application name as "a charging circuit and charging system", the entire contents of which are incorporated by reference in this application.

Technical field

The invention relates to the technical field of batteries, in particular to a charging circuit and a charging system.

Background technique

The operation of electronic equipment depends on the battery to provide electrical energy. For example, taking an aircraft such as an unmanned aerial vehicle as an example, the realization of functions such as flying and aerial photography of an unmanned aerial vehicle is inseparable from the supply of battery power. At present, with the continuous improvement of UAV technology, UAVs are more and more popular, and at the same time, people's requirements for UAVs are becoming higher and higher. Among them, for drones, their endurance is an important indicator to measure the performance of drones. Due to the limited energy density of its batteries, the drone's battery life has been improving slowly. At present, the endurance of drones that are relatively good in terms of endurance is usually only about 30 minutes. If you want the drone to fly longer, you can carry more spare batteries to replace the battery when the battery power is low; or charge the battery to ensure the flight and aerial photography needs of the drone.

For the way of carrying more spare batteries, it will obviously increase the user's cost and carrying burden, thereby causing user annoyance. Especially for the case of users carrying drones to fly outdoors, due to the inconvenience of outdoor charging, usually carrying multiple spare batteries to improve the flight time of the aircraft, and carrying multiple spare batteries will increase the trouble of carrying. For the method of charging the battery, since the voltage of the charging device used to charge the battery does not normally match the voltage of the battery, and the output voltage of the charging device is not stable, the output voltage of the charging device needs to be Make adjustments and transmit the adjusted voltage to the battery to ensure the normal charging of the battery.

At present, a voltage step-down circuit or a step-up circuit is usually used for voltage adjustment. However, only using the step-down circuit or the step-up circuit can not adapt well to the input voltage of different charging devices, so that different charging devices cannot well meet the charging requirements of the battery. For example, in order to meet the needs of power supply, such as meeting the power requirements of the drone's motor, the battery generally adopts a multi-string battery structure, and its voltage is within a voltage range. The voltage range does not match the voltage range of the battery voltage well. For example, the battery voltage range is 9V-13V, while the charging device voltage is 10V-14V. At this time, if only the step-down circuit is used to adjust the voltage of the charging device, or only the step-up circuit is used to adjust the voltage of the charging device, the charging device cannot meet the requirements for battery charging.

Summary of the invention

Embodiments of the present invention are directed to provide a charging circuit and a charging system, which can adapt to input voltages of different charging devices, so that different charging devices can meet battery charging requirements.

The embodiments of the present invention disclose the following technical solutions:

In a first aspect, an embodiment of the present invention provides a charging circuit, including:

A voltage input terminal, a first voltage output terminal, a second voltage output terminal, a buck-boost circuit and a buck circuit, the voltage input terminal is connected to the buck-boost circuit, and the buck-boost circuit is connected to the first A voltage output terminal is connected to the step-down circuit, and the step-down circuit is connected to the second voltage output terminal;

The buck-boost circuit is used to receive and adjust the input voltage input from the voltage input terminal to obtain a first adjusted voltage, and output the first adjusted voltage to the first voltage output terminal to pass the The first voltage output terminal outputs the first output voltage to charge the battery;

The buck circuit is used to receive and adjust the first adjustment voltage input by the buck-boost circuit to obtain a second adjustment voltage, and output the second adjustment voltage to the second voltage output terminal To charge the electric device by outputting the second output voltage through the second voltage output terminal.

In some embodiments, the charging circuit further includes a feedback circuit connected to the first voltage output terminal and the buck-boost circuit;

The feedback circuit is used to feed back the first output voltage output from the first voltage output terminal to the buck-boost circuit, and the buck-boost circuit performs voltage adjustment according to the first output voltage and the input voltage.

In some embodiments, the buck-boost circuit includes any one of the following buck-boost chips: BQ25700A, SC8802, ISL95338.

In some embodiments, when the buck-boost circuit includes BQ25700A, if the BQ25700A detects that the input voltage is higher than the first output voltage, the BQ25700A is in a buck state to perform buck adjustment; If the BQ25700A detects that the input voltage is lower than the first output voltage, the BQ25700A is in a boosted state to perform boost adjustment.

In some embodiments, the BQ25700A includes: a control chip, a first MOS tube, a second MOS tube, a third MOS tube, a fourth MOS tube, a first inductor, and a first capacitor;

The drain of the first MOS tube is connected to the voltage input terminal, the gate of the first MOS tube is connected to the HIDVR1 pin of the control chip, and the source of the first MOS tube is connected to the first The drains of the two MOS tubes are connected, and the drain of the second MOS tube is also connected to one end of the first inductor, the source of the second MOS tube is grounded, and the gate of the second MOS tube It is connected to the LODRV1 pin of the control chip, the other end of the first inductor is connected to the drain of the third MOS tube, and the drain of the third MOS tube is also connected to the fourth MOS tube The source of the third MOS tube is connected to the ground, the gate of the third MOS tube is connected to the LODRV2 pin of the control chip, the gate of the fourth MOS tube is connected to the control chip Is connected to the LODRV2 pin, the drain of the fourth MOS tube is connected to the first voltage output terminal, and the drain of the fourth MOS tube is also connected to one end of the first capacitor, the first The other end of a capacitor is grounded;

When the input voltage is higher than the first output voltage, the first MOS tube and the second MOS tube are in a switching state, the third MOS tube is in an off state, and the fourth MOS tube is in On state for step-down adjustment; when the input voltage is lower than the first output voltage, the third MOS tube and the fourth MOS tube are in the switching state, and the second MOS tube is in the off state In the on state, the first MOS tube is in a conducting state to perform boost regulation.

In some embodiments, the charging circuit further includes a QC protocol detection circuit, and the QC protocol detection circuit is connected to the second voltage output terminal and the step-down circuit;

The QC protocol detection circuit is used to perform QC protocol detection on the second output voltage output from the second voltage output terminal, and if the QC protocol is met, the step-down circuit outputs the second adjusted voltage to the second voltage output terminal Adjust to the corresponding voltage that conforms to the QC protocol for input to the second voltage output terminal.

In some embodiments, the QC protocol detection circuit includes any one of the following QC protocol detection chips: IP2161, TP1001, FP6601Q.

In some embodiments, when the QC protocol detection circuit includes IP2161, the second voltage output terminal is a USB port, the USB port includes a data negative signal terminal and a data positive signal terminal, and the DM pin of the IP2161 It is connected to the negative data terminal of the USB port, and the DP pin of the IP2161 is connected to the positive data terminal of the USB port.

In some embodiments, the charging circuit further includes an overvoltage protection circuit, the overvoltage protection circuit includes an overvoltage input terminal and an overvoltage output terminal, the overvoltage input terminal is connected to a voltage input terminal, and the overvoltage The output terminal is connected to the buck-boost circuit;

The overvoltage protection circuit is used to prevent the input voltage from being too high.

In some embodiments, the charging circuit further includes a first current-sense resistor and a second current-sense resistor, the buck-boost circuit includes a buck-boost input terminal and a buck-boost output terminal, and the first current-sense resistor Connected to the input terminal of the buck-boost, and the second current detection resistor is connected to the output terminal of the buck-boost;

The input current input to the buck-boost circuit is detected by the first current detection resistor, the output current from the buck-boost circuit is detected by the second current detection resistor, and the input current and the The output circuit is stored in the buck-boost circuit.

In some embodiments, the charging circuit further includes a processor, and the processor is in communication connection with the buck-boost circuit;

The processor is used to transmit data to the buck-boost circuit through the communication connection to configure current and voltage parameters for the buck-boost circuit.

In some embodiments, the charging circuit further includes a temperature detection circuit, and the temperature detection circuit is connected to the processor;

The temperature detection circuit is used to detect temperature information during charging, and send the temperature information to the processor, and the processor performs temperature adjustment according to the temperature information.

In some embodiments, the charging circuit further includes a display device, and the display device is connected to the processor;

The display device is used to display charging state information.

In some embodiments, the charging circuit further includes a linear regulator connected to the processor, and the linear regulator is used to regulate the voltage input to the processor .

In a second aspect, an embodiment of the present invention provides a charging system, which is used to charge a battery and an electric device, respectively;

The charging system includes a charging device and a charging circuit as described above, the charging device is connected to the charging circuit, and the charging circuit is connected to the battery and the electric device, respectively;

The charging device is used to provide the input voltage, which is adjusted by the charging circuit to separately charge the battery and the electric device.

In some embodiments, the charging device is a car battery, the battery is an aircraft battery, and the electrical equipment is an aircraft remote control device.

In various embodiments of the present invention, the input voltage input to the voltage input terminal of the charging circuit is adjusted through the step-up and step-down circuit of the charging circuit, so that the charging circuit can adapt to the input voltage of different charging devices, so that different charging devices Can meet the charging requirements of the battery. Moreover, the charging circuit outputs the first output voltage through the first voltage output terminal to charge the battery, and also outputs the second output voltage through the second voltage output terminal to charge the electric device, so that the battery and the electric power can be simultaneously charged The effect of charging the device.

BRIEF DESCRIPTION

One or more embodiments are exemplarily illustrated by the pictures in the corresponding drawings. These exemplary descriptions do not constitute a limitation on the embodiments, and elements with the same reference numerals in the drawings represent similar elements. Unless otherwise stated, the figures in the drawings do not constitute a scale limitation.

1 is a schematic diagram of an application environment of a charging circuit provided by an embodiment of the present invention;

2 is a schematic diagram of a charging circuit provided by an embodiment of the present invention;

3 is a schematic diagram of another charging circuit provided by an embodiment of the present invention;

4 is a schematic diagram of the BQ25700A provided by an embodiment of the present invention;

5 is a schematic diagram of a DC-DC buck converter provided by an embodiment of the present invention;

6 is a schematic diagram of IP2161 provided by an embodiment of the present invention;

7 is a schematic diagram of a charging system provided by an embodiment of the present invention.

detailed description

In order to make the objectives, technical solutions and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. Obviously, the described embodiments are a part of the embodiments of the present invention, but not all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by a person of ordinary skill in the art without making creative efforts fall within the protection scope of the present invention.

It should be noted that when an element is referred to as being “fixed” to another element, it can be directly on the other element or there can also be a centered element. When an element is considered to be "connected" to another element, it may be directly connected to another element or there may be a center element at the same time. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are for illustrative purposes only and are not meant to be the only embodiments.

Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the technical field of the present invention. The terminology used in the description of the invention herein is for the purpose of describing specific embodiments and is not intended to limit the invention. The term "and / or" as used herein includes any and all combinations of one or more related listed items. In addition, the technical features involved in the embodiments of the present invention described below can be combined with each other as long as there is no conflict with each other.

The battery as an energy source is a necessary component for the operation of various electronic devices. However, due to the limitation of the energy density of the battery, the time during which the battery can provide electrical energy to the electronic device is limited. For example, taking an aircraft such as an unmanned aerial vehicle as an example, it relies on a battery to provide electrical energy to various systems of the unmanned aerial vehicle to ensure the flight and aerial photography of the unmanned aerial vehicle.

Among them, the power supply time of the battery determines the endurance of the UAV, that is, the endurance, and the endurance and endurance of the UAV are an important factor to measure the performance of the UAV. Due to battery limitations, the drone's battery life has been improving slowly. Generally, the endurance of drones that are currently relatively good in terms of endurance performance is about 30 minutes.

Therefore, in order to increase the flight time of the drone so that it can fly longer, it usually carries a few spare batteries, or usually a charging device to charge the battery of the drone.

The method of carrying multiple batteries increases the cost on the one hand and increases the carrying burden on the other hand. Especially for the flying of outdoor drones, carrying multiple spare batteries will inevitably cause great annoyance for users.

For the method of charging the battery through the charging device, since the voltage of the charging device and the battery voltage do not necessarily match, if they do not match, the voltage of the charging device is generally adjusted, and the adjusted voltage is transmitted to the battery To ensure the normal charging of the battery.

At present, voltage regulation is usually performed by using a buck circuit or a boost circuit. Although the charging device can be adjusted by the buck circuit or the boost circuit to charge the battery, the problem of inconvenience in carrying multiple batteries can be solved, but the use of the buck circuit or the boost circuit cannot be well adapted to different charging devices. Input voltage, so that different charging devices can not meet the charging requirements of the battery well.

For example, in order to meet the needs of power supply, such as meeting the power requirements of the drone's motor, the battery generally adopts a multi-string battery structure, and its voltage is within a voltage range. The voltage range does not match the voltage range of the battery voltage very well. For example, a battery formed by three single cells connected in series has a voltage range of 9V-13V and a charging device voltage of 10V-14V. At this time, if only the step-down circuit is used to adjust the voltage of the charging device, or only the step-up circuit is used to adjust the voltage of the charging device, the charging device cannot satisfy the battery charging well Requirements.

Based on this, an embodiment of the present invention provides a charging circuit and a charging system, and the input voltage input to the voltage input terminal of the charging circuit is adjusted by the voltage step-up and step-down circuit of the charging circuit, so that the charging circuit can adapt to different charging devices Input voltage, so that different charging devices can meet the charging requirements of the battery.

In addition, the charging circuit outputs the first output voltage through the first voltage output terminal to charge the battery, and also outputs the second output voltage through the second voltage output terminal to charge the electric device, so that the battery and the electric power can be simultaneously charged The effect of charging the device.

The charging circuit and charging system provided in the embodiments of the present invention will be described in detail below in conjunction with the drawings.

Please refer to FIG. 1 for a schematic diagram of an application environment of a charging circuit provided by an embodiment of the present invention. Wherein, the application environment includes: a charging device 100, a charging circuit 200, a battery 300, and an electric device 400. The charging device 100 is connected to the charging circuit 200, and the charging circuit 200 is connected to the battery 300 and the electric device 400, respectively.

The charging device 100 is used to provide the input voltage, and the input voltage is adjusted by the charging circuit 200 to charge the battery 300 and the electric device 400 respectively.

The adjustment of the input voltage by the charging circuit 200 includes: adjusting the input voltage to increase or decrease the voltage, so that the voltage output by the charging circuit 200 to the battery 300 matches the operating voltage of the battery 300, thereby realizing the Charging; after the input voltage is adjusted by buck-boost, then the buck is adjusted so that the voltage output by the charging circuit 200 to the electric device 400 conforms to the protocol specified by the output port, thereby realizing the electric device 400 Of charging.

It should be noted that the agreement can be any suitable agreement. For example, in order to realize the fast charging of the electric device 400, the protocol may be a QC (Qualcomm, Quick Charge) protocol. For example, QC2.0 fast charging protocol, QC3.0 fast charging protocol, QC4.0 fast charging protocol and so on.

The charging device 100 may be any charging device that can input a voltage to charge the battery 300 and the electric equipment 400, for example, a car battery, a power bank, a charger, and the like.

The charging circuit 200 is a hardware circuit constructed by various hardware devices, chips, etc. The hardware device may include a buck-boost chip, a pressure chip, a protection circuit, and the like.

The battery 300 may be a battery of various electronic devices. For example, the battery 300 may be an aircraft battery, an electric bicycle battery, or the like. The battery 300 may be a lithium battery, a nickel-cadmium battery, other storage batteries, or the like. Among them, the aircraft may include: airships, drones, unmanned ships, and so on. The following uses drone as an example of an aircraft.

The drone may be a rotorcraft, for example, a multi-rotor aircraft propelled by multiple propulsion devices through the air. The embodiments of the present invention are not limited thereto, and the drone may also be other types of unmanned aircraft. Aircraft, such as fixed-wing UAVs, unmanned airships, umbrella-wing UAVs, flapping-wing UAVs, etc.

UAVs can include: flight control systems, UAV batteries and motors. The battery of the UAV is connected with the flight control system and the motor respectively, so as to provide power for the flight control system and the motor, so as to ensure the flight of the UAV. In addition, the flight control system is in communication with the motor so as to send control commands to the motor to control the turning on or off of the motor.

Generally, in order to meet the power requirements of the drone's motor for lift-off, etc., its battery generally adopts a multi-string battery structure. For example, the battery of the drone is composed of 3 or 4 single batteries connected in series. Among them, the number of batteries constituting the drone is not limited here.

Moreover, it can be understood that the above naming of the components of the drone is for identification purposes only, and should not be understood as a limitation to the embodiments of the present invention.

The electric device 400 may be a remote control device of an aircraft, or the like. Wherein, the remote control device may be: a remote controller, a mobile phone, a tablet, a wearable device, etc. Through the remote control device, you can control the UAV and other aircraft.

The above charging circuit 200 can well adapt to the input voltage of various charging devices, so that different charging devices 100 can meet the charging requirements of the battery 300, and can simultaneously charge the battery 300 and the electric device 400.

For example, taking the charging device 100 as the battery of the car, the battery 300 as the battery of the aircraft, and the electrical equipment 400 as the remote controller as an example, when performing an outdoor flight of the aircraft, due to limited charging conditions, the battery of the vehicle can usually be used as the vehicle ’s battery. Charge the battery and remote control. However, because the voltage of the battery of the car cannot be well matched with the voltage of the aircraft, for example, the voltage range of the battery of the aircraft formed by connecting three single cells in series is 9V-13V, while the voltage range of the battery of the car is generally in 10V-14V. Therefore, in order to ensure that the battery of the vehicle can charge the battery of the aircraft, the voltage can be adjusted through the voltage boost and drop of the charging circuit 200, so that the battery of the vehicle can be adapted to the battery of the aircraft. Moreover, since the charging circuit 200 is provided with two voltage output ports, the charging device 100 can simultaneously charge the battery of the aircraft and the remote controller, so as to solve the problem of charging the aircraft, especially to charge the battery of the aircraft outdoors Puzzles.

It should be noted that the above charging circuit 200 can be further extended to other suitable application environments, and is not limited to the application environment shown in FIG. 1. In addition, in an actual application process, the application environment may also include more or less power-consuming devices.

The charging circuit 200 provided by the embodiment of the present invention will be specifically described below with reference to FIG. 2. The charging circuit 200 includes a voltage input terminal 10, a buck-boost circuit 20, a buck circuit 30, a first voltage output terminal 40, and a second voltage output terminal 50. Wherein, the voltage input terminal 10 is connected to the buck-boost circuit 20, the buck-boost circuit 20 is connected to the first voltage output terminal 40 and the buck circuit 30, and the buck circuit 30 is connected to The second voltage output 50 is connected.

The voltage input terminal 10 is used to receive the voltage input by the external device, that is, the input voltage of the external device can be applied to the voltage input terminal 10. The external device may be the above-mentioned charging device 100, such as a car battery or a power bank.

The buck-boost circuit 20 is connected to the voltage input terminal 10. The buck-boost circuit 20 is used to receive and adjust the input voltage input from the voltage input terminal 10 to obtain a first adjusted voltage. Furthermore, the buck-boost circuit 20 outputs the first adjusted voltage to the first voltage output terminal 40 to output the first output voltage through the first voltage output terminal 40 to charge the battery 300. For example, to charge the battery of the above aircraft.

Through the step-up and step-down adjustment of the input voltage by the step-up and step-down circuit 20, different charging devices 100 can meet the charging requirements of the battery 300, so that the battery 300 can be charged by various charging devices. This method is particularly suitable for charging inconveniences. For example, when charging outdoors, the buck-boost circuit 20 can be used to charge the battery of an aircraft with a car battery.

In some embodiments, in order to better adjust the input voltage and make the voltage input to the battery 300 stable, the charging circuit 200 further includes a feedback circuit 60. The feedback circuit 60 is a circuit that completes the output of the output to the input. As shown in FIG. 3, the feedback circuit 60 is connected to the first voltage output terminal 40 and the buck-boost circuit 20.

Wherein, the feedback circuit 60 is used to feed back the first output voltage output by the first voltage output terminal 40 to the buck-boost circuit 20, so that the buck-boost circuit 20 is based on the first output voltage and Input voltage for voltage adjustment, such as boost adjustment and buck adjustment.

The feedback circuit 60 may be a resistance voltage divider circuit for sampling the first output voltage. The resistance voltage divider circuit is coupled to the first voltage output terminal 40, directly divides and samples the first output voltage, and feeds back the sampled first output voltage to the buck-boost circuit 20, so that the rise and fall The voltage circuit 20 performs voltage adjustment according to the first output voltage and the input voltage. The resistance voltage-dividing circuit includes a first voltage-dividing resistor and a second voltage-dividing resistor connected in series, and the connection point of the first voltage-dividing resistor and the second voltage-dividing resistor is the output end of the resistance voltage-dividing circuit.

The buck-boost circuit 20 may be a hardware circuit composed of buck-boost chips. Moreover, the buck-boost circuit 20 may be a DC-DC buck-boost circuit. The buck-boost circuit 20 includes any one of the following buck-boost chips: BQ25700A, SC8802, ISL95338. The following uses BQ25700A as an example of the buck-boost chip of the buck-boost circuit 20 to specifically describe the voltage regulation by the buck-boost circuit 20.

Wherein, the step-up and step-down circuit 20 performs voltage adjustment according to the first output voltage and the input voltage includes: if the BQ25700A detects that the input voltage is higher than the first output voltage, the BQ25700A is in the step-down state In order to adjust the buck; if the BQ25700A detects that the input voltage is lower than the first output voltage, the BQ25700A is in a boosted state to perform boost adjustment.

Specifically, as shown in FIG. 4, it is a schematic diagram of a BQ25700A provided by an embodiment of the present invention. The BQ25700A includes: a control chip 210, a first MOS tube Q1, a second MOS tube Q2, a third MOS tube Q3, a fourth MOS tube Q4, a first inductor L1, and a first capacitor C1.

The drain (D pole) of the first MOS transistor Q1 is connected to the voltage input terminal 10, and the gate (G pole) of the first MOS transistor Q1 is connected to the HIDVR1 pin of the control chip 210. The source (S pole) of the first MOS tube Q1 is connected to the drain of the second MOS tube Q2, and the drain of the second MOS tube Q2 is also connected to one end of the first inductor L1, The source of the second MOS transistor Q2 is grounded GND, the gate of the second MOS transistor Q2 is connected to the LODRV1 pin of the control chip 210, and the other end of the first inductor L1 is connected to the third MOS The drain of the tube Q3 is connected, and the drain of the third MOS tube Q3 is also connected to the source of the fourth MOS tube Q4, the source of the third MOS tube Q3 is grounded to GND, and the third The gate of the MOS transistor Q3 is connected to the LODRV2 pin of the control chip 210, the gate of the fourth MOS transistor Q4 is connected to the LODRV2 pin of the control chip 210, and the drain of the fourth MOS tube Q4 It is connected to the first voltage output terminal 40, and the drain of the fourth MOS transistor Q4 is also connected to one end of the first capacitor C1, and the other end of the first capacitor C1 is grounded to GND.

Among them, the working principle of adjusting the input voltage through BQ25700A is:

When it is detected that the input voltage is higher than the first output voltage, the first MOS transistor Q1 and the second MOS transistor Q2 are in a switching state, and the third MOS transistor Q3 is in an off state. The fourth MOS transistor Q4 is in a conducting state, so that the BQ25700A is in a step-down state to perform step-down adjustment. Wherein that the first MOS transistor Q1 and the second MOS transistor Q2 are in a switching state means that the first MOS transistor Q1 and the second MOS transistor Q2 are turned off or turned on at a certain switching frequency.

When it is detected that the input voltage is lower than the first output voltage, the third MOS transistor Q3 and the fourth MOS transistor Q4 are in a switching state, and the second MOS transistor Q2 is in an off state. The first MOS transistor Q1 is in a conducting state, so that the BQ25700A is in a boosting state to perform boosting adjustment. Where the third MOS transistor Q3 and the fourth MOS transistor Q4 are in a switching state means that the third MOS transistor Q3 and the fourth MOS transistor Q4 are turned off or turned on at a certain switching frequency.

By adjusting the BQ25700A, various charging devices 100 can meet the charging requirements of the battery 300, and provide a stable voltage for charging the battery 300.

Please refer back to FIG. 2, the buck circuit 30 is used to receive and adjust the first adjustment voltage input by the buck-boost circuit 20 to obtain a second adjustment voltage, and output the second adjustment voltage To the second voltage output terminal 50, the electric device 400 is charged by outputting the second output voltage through the second voltage output terminal 50. For example, charging electrical equipment such as the remote control of an aircraft.

The step-down circuit 30 may be a DC-DC step-down circuit. The step-down circuit 30 may be a hardware circuit composed of components. For example, the step-down circuit 30 may include a DC-DC step-down converter.

Specifically, as shown in FIG. 5, the DC-DC buck converter includes: a switch S, a diode VD, a second inductor L2, a second capacitor C2, and a resistor R. Among them, one end of the switch S is connected to the buck-boost circuit 20 as the input end of the DC-DC buck converter, the other end of the switch S is connected to the cathode of the diode VD, and the cathode of the diode VD is also connected to the One end is connected, the anode of the diode VD is grounded GND, the other end of the second inductor L2 is connected to one end of the second capacitor C2 and one end of the resistor R, and one end of the second capacitor C2 is used as the output of the DC-DC buck converter At the other end, the other end of the second capacitor C2 is grounded GND, and the other end of the resistor R is grounded GND. The working principle of the step-down adjustment of the first adjustment voltage input by the step-up and step-down circuit 20 through the DC-DC step-down converter is as follows:

Suppose that the voltage of the input DC-DC buck converter is V _i and the voltage of the output DC-DC buck converter is V _o . When the switch S is closed, the voltage across the second inductor L2 is (V _i- V _o ), at this time, the second inductance L2 is excited by the voltage (V _i -V _o ), and the magnetic flux increased by the second inductance L2 is: (V _i -V _o ) * T _on . _{Wherein, T on = t on / L} 2, L 2 is the inductance of the second inductor L2, _on switch S is closed for the duration of the time t.

When the switch S is turned off, the diode VD becomes conductive due to the continuous output current, the second inductor L2 is demagnetized, and the magnetic flux reduced by the second inductor L2 is: (V _o ) * T _off . Among them, T _off = t _off / L, t _off is the time that the switch S is off.

When the state where the switch S is closed and the switch is open reaches equilibrium, (V _i -V _o ) * T _on = (V _o ) * T _off , because the duty ratio D <1, V _i > V _o , to achieve Buck function.

In some embodiments, in order to realize fast charging of the electric device 400, the second voltage output terminal 50 that generally provides the second output voltage for the electric device 400 is a fast charging output port, such as QC (Qualcomm, Quick Charge) Fast charge output port, etc. For the case of using the QC fast charge output port to achieve fast charging, before the second output voltage is output through the second voltage output terminal 50 to charge the electric device 400, the QC protocol detection is required. Among them, the QC protocol detection circuit can be implemented by the QC protocol detection circuit.

Specifically, as shown in FIG. 3, the charging circuit 200 further includes a QC protocol detection circuit 70. Wherein, the QC protocol detection circuit 70 is connected to the second voltage output terminal 50 and the step-down circuit 30.

The QC protocol detection circuit 70 is configured to perform QC protocol detection on the second output voltage output by the second voltage output terminal 50. If the QC protocol detection circuit 70 detects compliance with the QC protocol, the buck circuit 30 adjusts the second adjusted voltage output to the second voltage output terminal 50 to the corresponding voltage that conforms to the QC protocol for input to the second Voltage output 50.

The QC protocol detection circuit 70 may be a hardware circuit composed of a QC protocol detection chip. The QC protocol detection circuit 70 includes any one of the following QC protocol detection chips: IP2161, TP1001, FP6601Q. The following uses IP2161 as an example of the QC protocol detection chip of the QC protocol detection circuit 70 to specifically describe the implementation of the QC protocol detection by the QC protocol detection circuit 70.

As shown in FIG. 6, it is a schematic diagram of IP2161 provided by an embodiment of the present invention. The IP2161 is connected to the second voltage output terminal 50. Wherein, the second voltage output terminal 50 is a USB port, and the USB port includes a data negative signal terminal DM and a data positive signal terminal DP. The DM pin of the IP2161 is connected to the data negative signal terminal DM of the USB port, and the DP pin of the IP2161 is connected to the data positive signal terminal DP of the USB port.

Among them, the QC protocol detection is performed through IP2161, so that the voltage step-down circuit 30 performs voltage adjustment according to the detection results in the following situations:

1. If IP2161 detects that the voltage of the DM signal is 0.6V, and when the voltage of the DP signal is 0.6V, IP2161 draws current to its FB network, which changes the feedback voltage of IP2161, and then causes the step-down circuit 30 to output to the USB port The voltage is adjusted to 12V;

2. If IP2161 detects that the voltage of the DM signal is 0.6V, and when the voltage of the DP signal is 3.3V, IP2161 draws current to its FB network to change the feedback voltage of IP2161, which in turn causes the step-down circuit 30 to output to the USB port The voltage is adjusted to 9V;

3. If IP2161 detects that the voltage of the DM signal is 0V and the voltage of the DP signal is 0.6V, IP2161 draws current to its FB network to change the feedback voltage, which in turn causes the voltage step-down circuit 30 to output the voltage adjustment of the USB port To 5V.

In addition, the default output voltage of the QC fast charging protocol is 5V. Only after the completion of the QC protocol detection, the buck circuit 30 will output the corresponding voltage value.

In some embodiments, in order to ensure the safety of the battery 300 and the electrical equipment 400 during the charging process, the charging circuit 200 is provided with a detection circuit that detects undervoltage, overvoltage, overtemperature, overcurrent, short circuit, etc. during the charging process , Components and protection circuits.

Specifically, please refer back to FIG. 3, the charging circuit 200 further includes: an overvoltage protection circuit 80, a first current detection resistor 81, a second current detection resistor 82, a processor 83, a temperature detection circuit 84, a display device 85 and Linear regulator 86.

The overvoltage protection circuit 80 includes an overvoltage input terminal 801 and an overvoltage output terminal 802, the overvoltage input terminal 801 is connected to the voltage input terminal 10, and the overvoltage output terminal 802 is connected to the buck-boost circuit 20 connections.

The overvoltage protection circuit 80 is used to prevent the input voltage from being too high and damaging other components. For example, an excessively high input voltage may cause the BQ25700A to be burnt out. The overvoltage protection circuit 80 may be a hardware circuit composed of components. For example, the overvoltage protection circuit 80 may be composed of a chip with an overvoltage protection function. For example, the overvoltage protection circuit 80 includes TPS2400.

It should be noted that the overvoltage protection circuit 80 is not a necessary circuit of the charging circuit 200, and it can be added or omitted according to actual use. For example, in some other embodiments, if the input voltage is not very high, the overvoltage protection circuit 80 The voltage protection circuit 80 may be omitted.

The first current detection resistor 81 is used to detect the current input to the buck-boost circuit 20, and the second current detection resistor 82 is the current output by the buck-boost circuit 20. Through the detection of input current and output current, in order to detect the overcurrent and short circuit in the charging process.

Specifically, the buck-boost circuit 20 includes a buck-boost input end 201 and a buck-boost output end 202, the first current-sense resistor 81 is connected to the buck-boost input end 201, and the second current-sense The resistor 82 is connected to the buck-boost output terminal 202.

Wherein, the first current detection resistor 81 detects the input current input to the buck-boost circuit 20, and the second current detection resistor 82 detects the output current from the buck-boost circuit 20, and The input current and the output circuit are stored in the buck-boost circuit 20.

The processor 83 is communicatively connected to the buck-boost circuit 20 so as to realize data interaction with the buck-boost circuit 20. Wherein, the processor 83 and the buck-boost circuit 20 can communicate through various suitable communication protocols, for example, I2C, serial port protocol or other protocols and so on.

The processor 83 is used to transmit data to the buck-boost circuit 20 through the communication connection to configure current-voltage parameters for the buck-boost circuit 20. The current and voltage parameters can be input undervoltage, input overvoltage, input current, output voltage, output current and other parameters. Through the configuration of current and voltage parameters, in order to protect the undervoltage, overvoltage, overcurrent, short circuit and other conditions during the charging process.

It should be noted that the processor 83 may be any suitable processor, for example, a control unit (Control Unit, CU), a micro control unit (Micro Controller Unit, MCU), a single-chip microcomputer, and so on.

The temperature detection circuit 84 is connected to the processor 83. The temperature detection circuit 84 is used to detect the temperature information during the charging process, so as to detect the over-temperature condition during the charging process. In addition, the temperature detection circuit 84 sends the temperature information to the processor 83, so that the processor 83 performs temperature adjustment according to the temperature information to prevent overheating during charging.

For example, when the temperature detection circuit 84 detects that the temperature rises to a certain value, for example, when the temperature detection circuit 84 detects that the temperature is greater than a preset temperature threshold, the processor 83 starts to configure parameters for the buck-boost circuit 20 so that the rise The output current of the buck circuit 20 is reduced, or the buck-boost circuit 20 is turned off, thereby reducing the temperature during charging.

The temperature detection circuit 84 may be a hardware circuit composed of components. For example, the temperature detection circuit 84 may be composed of a sensor with a temperature detection function, such as a temperature sensor.

The display device 85 is connected to the processor 83, and the display device 85 is used to display charging state information. For example, the state of charge information may include current information, voltage information, temperature information, and the like. For example, when an over-temperature condition occurs during charging, the display device 85 displays an over-temperature status indication. The display device 85 may be a display or the like.

The linear regulator 86 is connected to the processor 83. The linear regulator 86 is used to regulate the voltage input to the processor 83 so as to provide the processor 83 with a stable voltage. The linear regulator 86 may be a linear regulator such as a low dropout linear regulator (LDO).

The charging circuit 200 provided by the embodiment of the present invention adjusts the input voltage of the voltage input terminal 10 through the voltage step-up and step-down circuit 20 of the charging circuit 200, so that the charging circuit 200 can adapt to the input voltage of different charging devices , So that different charging devices can meet the charging requirements of the battery. Moreover, the charging circuit 200 outputs the first output voltage through the first voltage output terminal 40 to charge the battery 300, and also outputs the second output voltage through the second voltage output terminal 50 to charge the electric device 400, so that The effect of charging the battery 300 and the electric device 400.

In addition, the charging circuit 200 can also detect under-voltage, over-voltage, over-temperature, over-current, short circuit, etc. during the charging process to protect the safety during the charging process.

Please refer to FIG. 7, which is a schematic diagram of a charging system according to an embodiment of the present invention. The charging system 700 is used to charge the battery 300 and the electric equipment 400 respectively. The charging system 700 includes a charging device 100 and the above charging circuit 200. The charging device 100 is connected to the charging circuit 200, and the charging circuit 200 is connected to the battery 300 and the electric device 400, respectively.

The charging device 100 is used to provide the input voltage, and the input voltage is adjusted by the charging circuit 200 to charge the battery 300 and the electric device 400 respectively.

Wherein, the charging device 100 may be a storage battery of an automobile, the battery 300 may be a battery of an aircraft, etc., and the electrical equipment 400 may be a remote control device of the aircraft.

The charging system 700 provided by the embodiment of the present invention can realize that different charging devices can charge the battery 300. In addition to charging the battery 300, the electric device 400 can also be charged.

Finally, it should be noted that the above embodiments are only for illustrating the technical solutions of the present invention, rather than limiting them; under the idea of the present invention, the technical features in the above embodiments or different embodiments may also be combined, The steps can be implemented in any order, and there are many other variations of the different aspects of the present invention as described above. For simplicity, they are not provided in the details; although the present invention has been described in detail with reference to the foregoing embodiments, the ordinary The skilled person should understand that they can still modify the technical solutions described in the foregoing embodiments, or equivalently replace some of the technical features; and these modifications or replacements do not deviate the essence of the corresponding technical solutions from the implementation of this application. Examples of technical solutions.

Claims (16)

1. A charging circuit is characterized by comprising:

   A voltage input terminal, a first voltage output terminal, a second voltage output terminal, a buck-boost circuit and a buck circuit, the voltage input terminal is connected to the buck-boost circuit, and the buck-boost circuit is connected to the first A voltage output terminal is connected to the step-down circuit, and the step-down circuit is connected to the second voltage output terminal;

   The buck-boost circuit is used to receive and adjust the input voltage input from the voltage input terminal to obtain a first adjusted voltage, and output the first adjusted voltage to the first voltage output terminal to pass the The first voltage output terminal outputs the first output voltage to charge the battery;

   The buck circuit is used to receive and adjust the first adjustment voltage input by the buck-boost circuit to obtain a second adjustment voltage, and output the second adjustment voltage to the second voltage output terminal To charge the electric device by outputting the second output voltage through the second voltage output terminal.
2. The charging circuit according to claim 1, wherein the charging circuit further comprises a feedback circuit, and the feedback circuit is connected to the first voltage output terminal and the buck-boost circuit;

   The feedback circuit is used to feed back the first output voltage output from the first voltage output terminal to the buck-boost circuit, and the buck-boost circuit performs voltage adjustment according to the first output voltage and the input voltage.
3. The charging circuit according to claim 2, wherein the buck-boost circuit includes any one of the following buck-boost chips: BQ25700A, SC8802, ISL95338.
4. The charging circuit according to claim 3, wherein when the buck-boost circuit includes a BQ25700A, if the BQ25700A detects that the input voltage is higher than the first output voltage, the BQ25700A is in a buck State to adjust the buck; if the BQ25700A detects that the input voltage is lower than the first output voltage, the BQ25700A is in the boosted state to perform the boost adjustment.
5. The charging circuit according to claim 4, wherein the BQ25700A includes: a control chip, a first MOS tube, a second MOS tube, a third MOS tube, a fourth MOS tube, a first inductor, and a first capacitor;

   The drain of the first MOS tube is connected to the voltage input terminal, the gate of the first MOS tube is connected to the HIDVR1 pin of the control chip, and the source of the first MOS tube is connected to the first The drains of the two MOS tubes are connected, and the drain of the second MOS tube is also connected to one end of the first inductor, the source of the second MOS tube is grounded, and the gate of the second MOS tube It is connected to the LODRV1 pin of the control chip, the other end of the first inductor is connected to the drain of the third MOS tube, and the drain of the third MOS tube is also connected to the fourth MOS tube The source of the third MOS tube is connected to the ground, the gate of the third MOS tube is connected to the LODRV2 pin of the control chip, the gate of the fourth MOS tube is connected to the control chip Is connected to the LODRV2 pin, the drain of the fourth MOS tube is connected to the first voltage output terminal, and the drain of the fourth MOS tube is also connected to one end of the first capacitor, the first The other end of a capacitor is grounded;

   When the input voltage is higher than the first output voltage, the first MOS tube and the second MOS tube are in a switching state, the third MOS tube is in an off state, and the fourth MOS tube is in On state for buck adjustment; when the input voltage is lower than the first output voltage, the third MOS tube and the fourth MOS tube are in the switching state, and the second MOS tube is in the off state In the on state, the first MOS tube is in a conducting state to perform boost regulation.
6. The charging circuit according to any one of claims 1 to 5, wherein the charging circuit further comprises a QC protocol detection circuit, the QC protocol detection circuit and the second voltage output terminal and the step-down circuit connection;

   The QC protocol detection circuit is used to perform QC protocol detection on the second output voltage output from the second voltage output terminal, and if the QC protocol is met, the step-down circuit outputs the second adjusted voltage to the second voltage output terminal Adjust to the corresponding voltage that conforms to the QC protocol for input to the second voltage output terminal.
7. The charging circuit according to claim 6, wherein the QC protocol detection circuit includes any one of the following QC protocol detection chips: IP2161, TP1001, FP6601Q.
8. The charging circuit according to claim 7, wherein when the QC protocol detection circuit includes IP2161, the second voltage output terminal is a USB port, and the USB port includes a data negative signal terminal and a data positive signal terminal The DM pin of the IP2161 is connected to the negative data terminal of the USB port, and the DP pin of the IP2161 is connected to the positive data terminal of the USB port.
9. The charging circuit according to any one of claims 1-8, wherein the charging circuit further includes an overvoltage protection circuit, and the overvoltage protection circuit includes an overvoltage input terminal and an overvoltage output terminal. The voltage input terminal is connected to the voltage input terminal, and the overvoltage output terminal is connected to the buck-boost circuit;

   The overvoltage protection circuit is used to prevent the input voltage from being too high.
10. The charging circuit according to any one of claims 1-9, wherein the charging circuit further includes a first current-sense resistor and a second current-sense resistor, and the buck-boost circuit includes a buck-boost input terminal and At the buck-boost output end, the first current-sense resistor is connected to the buck-boost input end, and the second current-sense resistor is connected to the buck-boost output end;

    The input current input to the buck-boost circuit is detected by the first current detection resistor, the output current from the buck-boost circuit is detected by the second current detection resistor, and the input current and the The output circuit is stored in the buck-boost circuit.
11. The charging circuit according to any one of claims 1-10, wherein the charging circuit further comprises a processor, and the processor is in communication connection with the buck-boost circuit;

    The processor is used to transmit data to the buck-boost circuit through the communication connection to configure current and voltage parameters for the buck-boost circuit.
12. The charging circuit according to claim 11, wherein the charging circuit further comprises a temperature detection circuit, and the temperature detection circuit is connected to the processor;

    The temperature detection circuit is used to detect temperature information during charging, and send the temperature information to the processor, and the processor performs temperature adjustment according to the temperature information.
13. The charging circuit according to claim 11 or 12, wherein the charging circuit further comprises a display device, and the display device is connected to the processor;

    The display device is used to display charging state information.
14. The charging circuit according to any one of claims 11 to 13, wherein the charging circuit further comprises a linear regulator, the linear regulator is connected to the processor, and the linear regulator is used for The voltage input to the processor is regulated.
15. A charging system, characterized in that the charging system is used to charge the battery and the electrical equipment, respectively;

    The charging system includes a charging device and the charging circuit according to any one of claims 1 to 14, the charging device is connected to the charging circuit, and the charging circuit is connected to the battery and the electricity Device connection

    The charging device is used to provide the input voltage, which is adjusted by the charging circuit to separately charge the battery and the electric device.
16. The charging system according to claim 15, wherein the charging device is a battery of an automobile, the battery is a battery of an aircraft, and the electric equipment is a remote control device of the aircraft.

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