Quick charging control circuit, charger and control method thereof

Abstract

The embodiment of the invention discloses a fast charging control circuit, a charger and a control method thereof. The circuit comprises a plurality of output ports used for connecting load equipment; the first voltage conversion module is used for converting the alternating-current voltage into first direct-current voltage; the plurality of second voltage conversion modules are respectively connected with the first voltage conversion module and the corresponding output ports and are used for converting the first direct-current voltage into corresponding second direct-current voltage; the plurality of control modules are respectively connected with the corresponding output ports and the corresponding second voltage conversion modules; the main control module is connected with the first voltage conversion module and used for adjusting the first direct-current voltage to the maximum expected voltage. According to the embodiment of the invention, the input voltage can be dynamically adjusted according to the actual load demand, so that the output DC-DC power supply works in the optimal duty ratio state, the overall conversion efficiency of the system is improved, and the problem of low efficiency caused by the fixed input voltage of the existing multi-port fast charging adapter is solved, so that the new energy efficiency standard requirement is met.

Description

Technical Field

[0001] The embodiments of the present invention relate to the field of USB fast charging, and in particular to a fast charging control circuit, a charger and a control method thereof. Background Technology

[0002] With the widespread adoption of USB Type-C devices and the promotion of the USB Power Delivery protocol, multi-port USB fast charging adapters have become mainstream in the market. Traditional USB interfaces have a maximum output power of only 7.5W (5V 1.5A), while the USB PD protocol supports a maximum power output of 240W, capable of handling 3A or 5A current, and with an output voltage up to 48V, providing powerful charging capabilities for various electronic devices. However, with the release of new energy efficiency standards, stricter requirements have been placed on the conversion efficiency and standby power consumption of multi-output power supplies. The minimum Level I energy efficiency requirement is a standby power consumption of no more than 50mW, making efficient and flexible power control of multiple Type-C ports a pressing technical challenge.

[0003] Existing multi-USB Type-C port fast charging adapters generally employ an independent output architecture, with each port equipped with an independent fast charging protocol controller and output DC-DC power module. In this approach, the input AC-DC power supply typically uses a fixed voltage output method. The output voltage is set to a fixed high voltage value during the initial system design phase. This voltage needs to be higher than the highest voltage that any Type-C port can possibly output to ensure that any port can stably output the expected maximum voltage. While the fixed voltage design ensures system reliability, it introduces serious efficiency problems.

[0004] The core flaw in existing technologies lies in their inability to dynamically adjust the input voltage according to actual load requirements. When a USB Type-C port needs to output a lower voltage, the constant high voltage output from the input AC-DC power supply leads to a significant voltage difference between the input and output voltages of that output DC-DC power supply. In this situation, the duty cycle of the output DC-DC power supply becomes very low. Since the efficiency of a switching power supply is directly proportional to the duty cycle, a low duty cycle directly results in a sharp drop in conversion efficiency. Specifically, when the duty cycle is low, both the conduction and switching losses of the switching transistors increase significantly, ultimately leading to low overall system efficiency and severe heat generation. This not only affects device reliability but also makes it difficult to meet the requirements of new energy efficiency standards. Summary of the Invention

[0005] The main technical problem solved by the embodiments of the present invention is to provide a fast charging control circuit, a charger and a control method thereof, which can solve at least some of the defects of the existing fast charging control circuit.

[0006] In a first aspect, embodiments of the present invention provide a fast charging control circuit, comprising: a plurality of output ports for connecting to load devices; a first voltage conversion module for converting AC voltage to a first DC voltage; a plurality of second voltage conversion modules, respectively connected to the first voltage conversion module and a corresponding output port, for converting the first DC voltage to a corresponding second DC voltage; a plurality of control modules, respectively connected to a corresponding output port and a corresponding second voltage conversion module; the control modules are used to adjust the second DC voltage to the output voltage required by the corresponding connected load device; a main control module is connected to the first voltage conversion module and is used to adjust the first DC voltage to a maximum desired voltage, the maximum desired voltage being obtained by dividing the maximum value among the output voltages required by each load device connected to the corresponding output port by the maximum duty cycle of the second voltage conversion module; the plurality of control modules includes one main control module.

[0007] Optionally, the first voltage conversion module includes a transformer T1, a diode D1, and a resistor R. LED And an optocoupler U1; the primary side of the transformer T1 is connected to the AC voltage, the first terminal of the secondary side of the transformer T1 is connected to the anode of the diode D1, and the cathode of the diode D1 is connected to the resistor R. LED The first terminal of the transformer T1 is connected to the voltage input terminal of the corresponding second voltage conversion module and the voltage input terminal of the corresponding control module; the second terminal of the secondary side of the transformer T1 is connected to the reference ground; the resistor R LED The second end is connected to the anode of the optocoupler U1, and the cathode of the optocoupler U1 is connected to the optocoupler feedback pin of the main control module.

[0008] Optionally, the main control module includes an error amplifier OP, a switching transistor U2, resistors R1 and R2, control switches S1 and S2, a current source IS1, and a current source IS2. The drain of the switching transistor U2 is connected to the controlled terminal of the first voltage conversion module, the gate of the switching transistor U2 is connected to the output terminal of the error amplifier OP, and the source of the switching transistor U2 is connected to reference ground. The non-inverting input terminal of the error amplifier OP is connected to the second terminal of the resistor R1 and the first terminal of the resistor R2. The first terminal of the resistor R1 is connected to the output terminal of the first voltage conversion module. The inverting input terminal of the error amplifier OP is connected to a reference voltage, and the second terminal of the resistor R2 is connected to reference ground. The positive terminal of the current source IS1 is connected to the supply voltage, the negative terminal of the current source IS1 is connected to the first terminal of the control switch S1, the second terminal of the control switch S1 is connected to the first terminal of the control switch S2 and the feedback output terminal of the corresponding second voltage conversion module, the second terminal of the control switch S2 is connected to the positive terminal of the current source IS2, and the negative terminal of the current source IS2 is connected to reference ground.

[0009] Optionally, the second voltage conversion module includes capacitor C1, capacitor C2, resistor R3, resistor R4, and a voltage conversion unit; the first terminal of capacitor C1 is connected to the output terminal of the first voltage conversion module and the positive input terminal of the voltage conversion unit, and the negative input terminal of capacitor C1 and the voltage conversion unit is connected to reference ground; the positive output terminal of the voltage conversion unit is connected to the first terminal of capacitor C2, the first terminal of resistor R3, and the output voltage pin of the corresponding output port; the negative output terminal of the voltage conversion unit is connected to the second terminal of capacitor C2, the second terminal of resistor R4, and the ground pin of the corresponding output port; and the second terminal of resistor R3 is connected to the first terminal of resistor R4 and the voltage feedback pin of the corresponding control module.

[0010] Optionally, the plurality of control modules includes one master control module and the rest are slave control modules. The master control module is communicatively connected to the slave control modules through clock signal lines and data signal lines.

[0011] Optionally, the slave control module includes a control switch S1, a control switch S2, a current source IS1, and a current source IS2; the positive terminal of the current source IS1 is connected to the power supply voltage, the negative terminal of the current source IS1 is connected to the first terminal of the control switch S1, the second terminal of the control switch S1 is connected to the first terminal of the control switch S2 and the feedback output terminal of the corresponding second voltage conversion module, the second terminal of the control switch S2 is connected to the positive terminal of the current source IS2, and the negative terminal of the current source IS2 is connected to the reference ground.

[0012] In a second aspect, embodiments of the present invention provide a charger, including: the fast charging control circuit as described in the first aspect.

[0013] Thirdly, embodiments of the present invention provide a control method applied to the fast charging control circuit as described in the first aspect, comprising: when any output port is connected to a load device, the main control module adjusts the first DC voltage to a preset maximum threshold; after waiting for a preset time, if a load device is detected connected to other output ports, the main control module adjusts the first DC voltage to the maximum desired voltage; if no load device is detected connected to other output ports, the first DC voltage is adjusted to the desired output voltage of the corresponding connected load device.

[0014] Optionally, if a load device is detected connected to another output port, the main control module adjusts the first DC voltage to the maximum desired voltage, including: when the slave control module detects that a load device is connected to the corresponding output port, it sends connection status information to the main control module; the main control module obtains the output voltage required by each connected load device; the main control module obtains the maximum value among the output voltages required by each load device and divides it by the maximum duty cycle of the second voltage conversion module to obtain the maximum desired voltage; the main control module adjusts the first DC voltage to the maximum desired voltage.

[0015] Optionally, if no load device is detected connected to other output ports, adjusting the first DC voltage to the desired output voltage of the corresponding connected load device includes: the main control module obtaining the output voltage required by the connected load device and dividing it by the maximum duty cycle of the second voltage conversion module to obtain the desired output voltage; the main control module adjusting the first DC voltage to the desired output voltage.

[0016] The beneficial effects of the embodiments of the present invention are as follows: Unlike the prior art, the embodiments of the present invention can dynamically adjust the input voltage according to the actual load demand, so that the output DC-DC power supply works in the optimal duty cycle state, significantly improving the overall conversion efficiency of the system, solving the problem of low efficiency caused by fixed input voltage in existing multi-port fast charging adapters, and meeting the requirements of the new energy efficiency standards. Attached Figure Description

[0017] One or more embodiments are illustrated by way of example with reference to the accompanying drawings. These illustrations do not constitute a limitation on the embodiments. Elements having the same reference numerals in the drawings are denoted as similar elements. Unless otherwise stated, the figures in the drawings are not to be limited by scale.

[0018] Figure 1This is a schematic diagram of an existing multi-USB Type-C port fast charging adapter circuit; Figure 2 It shows Figure 1 The circuit topology of the input AC-DC power supply in the circuit shown; Figure 3 This is a schematic diagram of a fast charging control circuit provided in an embodiment of the present invention; Figure 4 It shows Figure 3 The circuit topology of the main control module and the second voltage conversion module in the circuit shown; Figure 5 It shows Figure 3 The specific connection relationship of the fast charging control circuit is shown below. Figure 6 A flowchart illustrating a control method provided by an embodiment of the present invention. Detailed Implementation

[0019] To facilitate understanding of this application, a more detailed description is provided below with reference to the accompanying drawings and specific embodiments. It should be noted that when an element is described as being "fixed to" another element, it can be directly on the other element, or one or more intermediate elements may exist between them. When an element is described as being "connected" to another element, it can be directly connected to the other element, or one or more intermediate elements may exist between them. The terms "upper," "lower," "inner," "outer," "bottom," etc., used in this specification indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application. Furthermore, the terms "first," "second," "third," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0020] Unless otherwise defined, all technical and scientific terms used in this specification have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the scope of this application. The term "and / or" as used in this specification includes any and all combinations of one or more of the associated listed items.

[0021] Furthermore, the technical features involved in the different embodiments of this application described below can be combined with each other as long as they do not conflict with each other.

[0022] The technical solutions in this application will be described below with reference to the accompanying drawings.

[0023] Reference Figure 1The diagram shows a conventional multi-USB Type-C port fast charging adapter circuit. Existing solutions employ an independent output architecture to achieve multi-port charging functionality. In some embodiments of this application, the input AC-DC power supply is responsible for converting AC voltage to DC voltage (VAC-DC), and multiple output DC-DC power supplies are connected to their respective USB Type-C ports, each equipped with an independent fast charging protocol controller.

[0024] The fast charging protocol controller connects to the corresponding output DC-DC power supply via the FB pin to achieve precise control of the output voltage VBUS. As an example, and not a limitation, when a load device is connected to the adapter via a USB Type-C port, the fast charging protocol controller communicates and negotiates with the device via the CC pin to determine appropriate charging voltage and current parameters.

[0025] Reference Figure 2 The input AC-DC power supply circuit topology shown is typical of existing AC-DC power supplies that employ a flyback switching power supply topology. In some embodiments of this application, the primary side of transformer T1 is connected to the AC input voltage, and the secondary side generates a DC output voltage VAC-DC through rectifier diodes and filter capacitors.

[0026] To achieve stable control of the output voltage, the existing technical solution uses an optocoupler U1, a three-terminal adjustable shunt parallel voltage regulator U2, and a voltage divider resistor network R. UP R DOWN The feedback control circuit is composed of [various components]. As an example and not a limitation, when the output voltage VAC-DC deviates from the set value, the voltage divider network detects the voltage change and controls the conduction state of the optocoupler U1 through the three-terminal regulator U2, thereby adjusting the operating state of the transformer T1 to stabilize the output voltage.

[0027] The core problem with existing technical solutions lies in the use of a fixed voltage output for the input AC-DC power supply. In some embodiments of this application, to ensure that all USB Type-C ports can output the expected maximum voltage, the output voltage VAC-DC of the input AC-DC power supply is set to a fixed high voltage value, which is typically higher than the highest output voltage that all ports may require. While the fixed voltage design ensures system reliability and compatibility, it introduces serious efficiency problems. By way of example, and not limitation, when a USB Type-C port needs to output a lower voltage (e.g., 5V), because the input voltage VAC-DC is always maintained at a high level (e.g., above 20V), there is a large voltage difference between the input and output voltages of the output DC-DC power supply.

[0028] Specifically, the conversion efficiency of a switching power supply is closely related to its duty cycle, which is calculated by dividing the output voltage by the input voltage. In some embodiments of this application, when the input voltage is much higher than the output voltage, the duty cycle becomes very low, leading to a significant increase in the conduction and switching losses of the switching transistors, ultimately causing a sharp drop in the overall system conversion efficiency. Inefficient operation not only wastes energy but also generates a large amount of heat, affecting the reliability and lifespan of the equipment. As an example, and not a limitation, in actual testing, when the output voltage is 5V and the input voltage is 24V, the conversion efficiency of some output DC-DC power supplies may drop below 60%, far lower than the efficiency level of over 85% when operating at a high duty cycle. With the continuous improvement of energy efficiency standards, especially the release of new standards, more stringent requirements have been placed on the conversion efficiency and standby power consumption of multi-output power supplies. In some embodiments of this application, the minimum Level I energy efficiency requirement is that standby power consumption should not exceed 50mW, which is difficult for traditional fixed-voltage solutions to meet.

[0029] Another limitation of existing technical solutions is that the control of each port is relatively independent, lacking a system-level coordinated control mechanism. As an example, and not a limitation, when multiple ports operate simultaneously, each fast-charging protocol controller can only independently control its corresponding output DC-DC power supply, failing to achieve coordinated optimization between the input AC-DC power supply and multiple output ports. This independent control mode limits the potential for improving the overall system efficiency and increases the complexity and cost of the control circuitry. In some embodiments of this application, due to the lack of a unified power management strategy, the system cannot dynamically adjust the input voltage according to the actual load, thus missing opportunities for efficiency optimization.

[0030] To address the problems existing in the prior art, this invention provides a fast charging control circuit, the schematic diagram of which is shown below. Figure 3 As shown, Figure 3 The fast charging control circuit shown includes a first voltage conversion module 100, several second voltage conversion modules, several control modules, and several output ports.

[0031] In some embodiments of this application, the first voltage conversion module 100 is used to convert AC voltage into a first DC voltage. By way of example and not limitation, the first voltage conversion module 100 can employ various switching power supply topologies such as flyback, forward, or bridge to implement the AC-DC voltage conversion function. Specifically, when AC voltage is input to the first voltage conversion module 100, the internal switching circuit rectifies, filters, and stabilizes the AC voltage through high-frequency switching operations, ultimately outputting a stable first DC voltage for use by subsequent circuits.

[0032] It should be noted that the output voltage of the first voltage conversion module 100 is not a fixed value, but can be dynamically adjusted according to the actual load requirements under the action of the main control module, thereby maximizing system efficiency.

[0033] Specifically, such as Figure 3 As shown, the fast charging control circuit includes multiple second voltage conversion modules, including second voltage conversion module 210, second voltage conversion module 220, and second voltage conversion module 2N0, etc. By way of example and not limitation, each second voltage conversion module is connected to the first voltage conversion module 100 and the corresponding output port, and is used to convert the first DC voltage into the corresponding second DC voltage.

[0034] In some embodiments of this application, the second voltage conversion module operates based on DC-DC voltage conversion technology. It is easy to understand that when the first DC voltage is input to the second voltage conversion module, the internal switching regulation circuit controls the output voltage by adjusting the duty cycle of the switch according to the voltage requirements of the load device. Specifically, the duty cycle determines the voltage conversion efficiency; when the duty cycle is close to its maximum value, the conversion efficiency reaches its optimal state.

[0035] By way of example and not limitation, the second voltage conversion module 210 is connected to the output port 410 to provide the required second DC voltage to the load device connected to the port. In some embodiments of this application, different second voltage conversion modules can simultaneously output different voltage values ​​to meet the charging needs of different load devices.

[0036] Specifically, such as Figure 3 As shown, the fast charging control circuit includes multiple control modules, including control module 310, control module 320, and control module 3N0. Each control module is connected to a corresponding output port and a corresponding second voltage conversion module, and is responsible for adjusting the second DC voltage to the output voltage required by the corresponding connected load device.

[0037] In some embodiments of this application, the control module operates based on fast charging protocol identification and voltage regulation technology. By way of example and not limitation, when a load device is connected to the output port, the control module first establishes a handshake with the load device via a communication protocol to identify the device's charging needs and protocol type. Specifically, based on the protocol negotiation results, the control module sends a control signal to the corresponding second voltage conversion module to adjust the output voltage to the precise value required by the load device.

[0038] The control module also features real-time monitoring capabilities, continuously monitoring the output voltage and current status to ensure the safety and stability of the charging process. In some embodiments of this application, the control module uses a feedback control mechanism to precisely adjust the second voltage conversion module, immediately making adjustments when the output voltage deviates from the target value.

[0039] Specifically, such as Figure 3 As shown, the fast charging control circuit includes multiple output ports, including output port 410, output port 420, and output port 4N0. As an example and not a limitation, each output port is used to connect a load device, providing a charging interface for various electronic devices. It is easy to understand that the output ports can adopt USB Type-C, USB-A, or other standardized interface forms to accommodate the connection needs of different devices.

[0040] In some embodiments of this application, the output port not only provides power transmission functionality but also supports data communication functionality. Specifically, the output port integrates power transmission pins and communication pins, enabling the control module to negotiate protocols and monitor the status of connected load devices.

[0041] It should be noted that among the several control modules, there is one main control module and the rest are subordinate control modules. In some embodiments of this application, the main control module is connected to the first voltage conversion module 100 and is responsible for adjusting the first DC voltage to the maximum desired voltage.

[0042] As an example rather than a limitation, the main control module first collects the load voltage requirement information of each output port, then calculates the maximum value among the output voltages required by all load devices, and then divides the maximum value by the maximum duty cycle of the second voltage conversion module to obtain the maximum expected voltage as the output target of the first voltage conversion module 100.

[0043] It should be noted that the maximum duty cycle refers to the maximum operating duty cycle value preset during the design of a single second voltage conversion module, not the maximum value of the duty cycle among multiple second voltage conversion modules. Second voltage conversion modules of the same type have the same maximum duty cycle. As an example and not a limitation, the maximum duty cycle is usually set to a fixed value between 0.8 and 0.95. This value is determined during the system design phase and represents the upper limit of the duty cycle at which the second voltage conversion module can operate stably.

[0044] In some embodiments of this application, the master control module communicates with the slave control module via clock signal lines and data signal lines. Specifically, the clock signal line is used to provide a synchronous clock signal to ensure coordinated operation between the various control modules; the data signal line is used to transmit control commands and status information, enabling the master control module to uniformly manage the slave control modules.

[0045] When the load demand of a certain output port changes, the corresponding slave control module reports the status information to the master control module through the data signal line. The master control module recalculates the maximum expected voltage based on the global information and optimizes the voltage by controlling the first voltage conversion module 100.

[0046] The slave control module is primarily responsible for local voltage regulation and device communication functions. In some embodiments of this application, the slave control module receives instructions from the master control module while independently completing protocol negotiation and voltage regulation tasks with the corresponding load device.

[0047] The specific working process is as follows: The main control module first adjusts the first DC voltage to the preset safe voltage level; when the load device is detected to be connected, the main control module dynamically adjusts the first DC voltage to the maximum expected voltage level according to the global load situation, so that each second voltage conversion module can work in a high duty cycle state, thereby maximizing the overall efficiency of the system.

[0048] In some embodiments of this application, reference is made to Figure 4 The specific circuit topology shown, taking the second voltage conversion module 210, control module 310, and output port 410 as examples, provides a detailed explanation of the specific circuit configuration of the fast charging control circuit. Specifically, the control module 310, as the main control module, is responsible for system-level voltage regulation and coordination control functions.

[0049] like Figure 4 The first voltage conversion module 100 shown includes a transformer T1, a diode D1, and a resistor R. LED In addition, there are devices such as optocoupler U1. In some embodiments of this application, the primary side of transformer T1 is connected to the AC voltage input terminal to achieve input voltage isolation and transformation functions.

[0050] Specifically, the first terminal of the secondary side of transformer T1 is connected to the anode of diode D1, and the cathode of diode D1 is connected to the first terminal of resistor RLED, the corresponding voltage input terminal of the second voltage conversion module 210, and the voltage input terminal of the control module 310. Diode D1 acts as a rectifier, rectifying the AC voltage output from the secondary side of transformer T1 into DC voltage while preventing the flow of reverse current.

[0051] In some embodiments of this application, the second terminal of the secondary side of transformer T1 is connected to reference ground, forming a complete voltage output circuit. As an example and not a limitation, resistor R... LED The second end is connected to the anode of the optocoupler U1, and the cathode of the optocoupler U1 is connected to the optocoupler feedback pin of the main control module 310, thus forming a feedback control path for the output voltage.

[0052] Specifically, the working principle of the optocoupler U1 is based on photoelectric conversion technology. When the control module 310 needs to adjust the output voltage of the first voltage conversion module 100, it controls the current flowing through the optocoupler U1 to change the brightness of its internal light-emitting diode, thereby affecting the conduction degree of the phototransistor and ultimately adjusting the working state of the transformer T1.

[0053] In some embodiments of this application, the main control module 310 includes core components such as an error amplifier OP, a switching transistor U2, resistors R1 and R2, control switches S1 and S2, current source IS1, and current source IS2. By way of example and not limitation, the switching transistor U2 is an NMOS transistor, which features fast switching characteristics and low on-resistance.

[0054] Specifically, the drain of the switching transistor U2 is connected to the controlled terminal of the first voltage conversion module 100 to control the current of the optocoupler U1. The gate of the switching transistor U2 is connected to the output terminal of the error amplifier OP, and the source of the switching transistor U2 is connected to the reference ground, forming a current control switching circuit.

[0055] In some embodiments of this application, the non-inverting input of the error amplifier OP is connected to the second terminal of resistor R1 and the first terminal of resistor R2 to form a voltage detection divider network. The first terminal of resistor R1 is connected to the output of the first voltage conversion module 100 for sampling the actual value of the first DC voltage.

[0056] Specifically, the inverting input of the error amplifier OP is connected to the reference voltage VDAC, and the second terminal of resistor R2 is connected to the reference ground. The error amplifier OP generates a corresponding control signal to drive the switching transistor U2 by comparing the difference between the actual voltage after voltage division and the reference voltage VDAC, thereby achieving precise adjustment of the first DC voltage.

[0057] In some embodiments of this application, the positive terminal of the current source IS1 is connected to the supply voltage VDD, and the negative terminal of the current source IS1 is connected to the first terminal of the control switch S1. By way of example and not limitation, the current source IS1 provides a stable output current for injecting a current signal into the feedback output terminal of the second voltage conversion module 210.

[0058] Specifically, the second terminal of control switch S1 and the first terminal of control switch S2, as well as the feedback output terminal of the corresponding second voltage conversion module 210, are connected to form a bidirectional current regulation path. The second terminal of control switch S2 is connected to the positive terminal of current source IS2, and the negative terminal of current source IS2 is connected to reference ground, forming a current extraction circuit.

[0059] In some embodiments of this application, the bidirectional adjustment of the output voltage of the second voltage conversion module 210 can be achieved by controlling the on / off states of switches S1 and S2. By way of example and not limitation, when it is necessary to increase the output voltage, control switch S2 is closed, and current is drawn from the feedback output terminal through current source IS2; when it is necessary to decrease the output voltage, control switch S1 is closed, and current is injected into the feedback output terminal through current source IS1.

[0060] Specifically, the second voltage conversion module 210 includes capacitors C1 and C2, resistors R3 and R4, and a voltage conversion unit 211. The first terminal of capacitor C1 is connected to the output terminal of the first voltage conversion module 100 and the positive input terminal of the voltage conversion unit 211, and the negative terminal of capacitor C1 and the negative input terminal of the voltage conversion unit 211 are connected to reference ground.

[0061] In some embodiments of this application, capacitor C1 serves as an input filter capacitor to filter out high-frequency ripple components in the first DC voltage, providing a stable input voltage for the voltage conversion unit 211. By way of example and not limitation, capacitor C1 may be a low-ESR electrolytic capacitor or a ceramic capacitor, which possesses good filtering characteristics and temperature stability.

[0062] Specifically, the positive output terminal of voltage conversion unit 211 is connected to the first terminal of capacitor C2, the first terminal of resistor R3, and the output voltage pin of the corresponding output port 410. By way of example and not limitation, voltage conversion unit 211 adopts a switching regulator topology, which controls the magnitude of the output voltage by adjusting the duty cycle of the internal switch.

[0063] In some embodiments of this application, the negative output terminal of the voltage conversion unit 211 is connected to the second terminal of capacitor C2, the second terminal of resistor R4, and the ground pin of the corresponding output port 410 to form a complete output voltage loop. By way of example and not limitation, capacitor C2 serves as an output filter capacitor to reduce the ripple of the output voltage and improve voltage quality.

[0064] Specifically, the second end of resistor R3 and the first end of resistor R4 are connected to the voltage feedback pin of the corresponding control module 310 to form an output voltage detection divider network. By adjusting the ratio of resistors R3 and R4, the detection ratio of the output voltage can be set, thereby achieving precise control of different output voltage levels.

[0065] In some embodiments of this application, when a load device is connected to the system via output port 410, the control module 310 first negotiates a protocol with the device via a communication pin to determine the required output voltage level. As an example and not a limitation, the control module 310 adjusts the states of control switches S1 and S2 according to the negotiation result, changes the current flowing through the voltage divider network, and thereby adjusts the output voltage of the voltage conversion unit 211 to the target value.

[0066] Specifically, the main control module 310 simultaneously monitors the voltage signal fed back from the voltage divider network. When it detects that the first DC voltage needs adjustment, it controls the operating state of the optocoupler U1 through the error amplifier OP and the switching transistor U2, thereby dynamically adjusting the output voltage of the first voltage conversion module 100. It is easy to understand that by coordinating the control of the first voltage conversion module 100 and the second voltage conversion module 210, the voltage conversion unit 211 can operate at its optimal duty cycle, thus achieving efficient voltage conversion and power management.

[0067] Specifically, the control module is actually implemented using a fast charging protocol controller, such as... Figure 5 As shown, the fast charging protocol controller 310, as the main control module, has multiple functional pins, including OPTO, FB1, SCL, SDA, EN1, and VIN1. In some embodiments of this application, each pin assumes a different functional role, and through specific connection relationships, coordinates the control of the first voltage conversion module 100 and the second voltage conversion module 210.

[0068] Specifically, the OPTO pin of the fast charging protocol controller 310 is connected to the optocoupler U1 in the first voltage conversion module 100. As an example, and not a limitation, the OPTO pin outputs a control signal to drive the operating state of the optocoupler U1, thereby adjusting the output voltage level of the first voltage conversion module 100. It is easy to understand that the signal change on the OPTO pin directly affects the duty cycle of the transformer T1, thus achieving dynamic adjustment of the first DC voltage.

[0069] In some embodiments of this application, the FB1 pin of the fast charging protocol controller 310 is connected to the feedback output terminal of the second voltage conversion module 210. Specifically, the FB1 pin receives the voltage feedback signal from the second voltage conversion module 210, and can also inject or extract current into the feedback loop to achieve precise adjustment of the output voltage. It is easy to understand that the bidirectional control capability of the FB1 pin enables the fast charging protocol controller 310 to flexibly adjust the output voltage of the second voltage conversion module 210 to the value required by the load device.

[0070] By way of example and not limitation, the EN1 pin of the fast charging protocol controller 310 is connected to the enable control terminal of the second voltage conversion module 210 to control the operating state of the module. In some embodiments of this application, when no load device is connected to the output port 410, the fast charging protocol controller 310 can turn off the second voltage conversion module 210 through the EN1 pin, thereby reducing the standby power consumption of the system.

[0071] Specifically, the VIN1 pin of the fast charging protocol controller 310 is connected to the output of the first voltage conversion module 100 to monitor the actual value of the first DC voltage. The VIN1 pin provides input voltage information to the fast charging protocol controller 310, enabling it to calculate the optimal voltage regulation strategy based on the input voltage level and output voltage requirements.

[0072] In some embodiments of this application, the fast charging protocol controller 310 also includes communication and power pins directly connected to the output port 410. Specifically, the CC / D+ / D- pin group is connected to the corresponding pins of the output port 410 to enable communication with the USB fast charging protocol of the load device. By way of example and not limitation, the CC pin is used for configuration detection and power transfer negotiation, and the D+ and D- pins are used for data communication and signal transmission of certain fast charging protocols.

[0073] The fast charging protocol controller 310 can identify the type of connected device and its charging requirements through the CC / D+ / D- pins, and negotiate the corresponding voltage and current according to different fast charging protocols such as USB PD, QC, and AFC. In some embodiments of this application, after the negotiation is completed, the fast charging protocol controller 310 adjusts the control signal of the FB1 pin according to the negotiation result, so that the second voltage conversion module 210 outputs the precise voltage required by the device.

[0074] like Figure 5 As shown, the fast charging protocol controller 320, as a slave control module, has functional pins such as FB2, EN2, VIN2, and CC / D+ / D- pin groups. As an example and not a limitation, the pin functions of the fast charging protocol controller 320 are similar to those of the master control module 310, but its primary responsibility is to control the corresponding second voltage conversion module 220 and output port 420.

[0075] In some embodiments of this application, the master control module 310 and the slave control module 320 are connected via the SCL pin and the SDA pin. Specifically, the SCL pin transmits a synchronization clock signal, and the SDA pin transmits a data signal; together, they constitute an I2C communication bus. It is easy to understand that through the I2C bus, the master control module 310 can obtain the operating status and load requirements of each slave control module.

[0076] As an example and not a limitation, when the slave control module 320 detects a new load device connected to the output port 420, it reports the device information and voltage requirements to the master control module 310 via the SDA pin. In some embodiments of this application, after collecting the requirement information from all slave control modules, the master control module 310 calculates the maximum expected voltage required by the system and adjusts the output voltage of the first voltage conversion module 100 via the OPTO pin.

[0077] Specifically, the fast charging protocol controller 3N0, as another slave control module, also has FBn, ENn, VINn pins and CC / D+ / D- pin groups. It's easy to understand that the parallel connection of multiple slave control modules allows the system to support the simultaneous operation of multiple output ports, each providing the corresponding charging voltage and current according to the needs of the connected device.

[0078] In some embodiments of this application, the VIN pins of all fast charging protocol controllers are connected to the output of the first voltage conversion module 100, forming a common input voltage monitoring network. By way of example and not limitation, when the main control module 310 adjusts the first DC voltage, all fast charging protocol controllers can monitor the voltage change in real time and adjust their respective control strategies accordingly.

[0079] Specifically, the fast charging protocol controller integrates functional modules such as a voltage detection circuit, a protocol identification circuit, a PWM control circuit, and a communication interface circuit. It's easy to understand that the voltage detection circuit monitors the input and output voltage status through the VIN and FB pins; the protocol identification circuit communicates and negotiates with the load device through the CC / D+ / D- pins; and the PWM control circuit generates corresponding control signals to adjust the operating state of the second voltage conversion module.

[0080] In some embodiments of this application, when the system starts up, the main control module 310 first sets the first DC voltage to the safe startup voltage via the OPTO pin. As an example and not a limitation, when a load connection is detected at any output port, the corresponding fast charging protocol controller, after completing device identification and protocol negotiation, reports the voltage requirement information to the main control module 310 via the I2C bus.

[0081] Specifically, the main control module 310 calculates the maximum value of the output voltage required by each load device based on all collected voltage demand information, and divides this maximum value by the maximum duty cycle of the second voltage conversion module to obtain the maximum expected voltage. It is easy to understand that the main control module 310 then adjusts the output of the first voltage conversion module 100 to the maximum expected voltage level via the OPTO pin, thereby enabling all second voltage conversion modules to operate at a higher duty cycle, maximizing the overall system efficiency.

[0082] Unlike existing technologies, the embodiments of the present invention can dynamically adjust the input voltage according to the actual load requirements, so that the output DC-DC power supply works in the optimal duty cycle state, significantly improving the overall conversion efficiency of the system, solving the problem of low efficiency caused by fixed input voltage in existing multi-port fast charging adapters, and meeting the requirements of the new energy efficiency standards.

[0083] Based on the fast charging control circuit provided in the above embodiments, the present invention also provides a charger, which includes the fast charging control circuit provided in the above embodiments.

[0084] Based on the fast charging control circuit provided in the above embodiments, this invention also provides a control method, the flowchart of which is shown below. Figure 6 As shown, the control method specifically includes the following steps: Step S100: When any output port is connected to a load device, the main control module adjusts the first DC voltage to the preset maximum threshold.

[0085] In some embodiments of this application, the main control module determines whether a load device is connected by monitoring the device detection signals of each fast charging protocol controller. It is easy to understand that when the output port is in an unloaded state, the corresponding fast charging protocol controller will continuously monitor the voltage change of the CC pin, and once a load device is detected, it will immediately send a device connection notification to the main control module.

[0086] By way of example and not limitation, when a user plugs a smartphone's USB Type-C data cable into the output port, the fast charging protocol controller detects a voltage jump on the CC pin and identifies a connection event of the load device. In some embodiments of this application, after receiving the device access signal, the main control module immediately initiates a first DC voltage adjustment procedure.

[0087] Specifically, the preset maximum threshold is set based on system compatibility and safety considerations. It's easy to understand that the preset maximum threshold is typically set to the highest safe voltage value supported by the system, sufficient to meet the initialization requirements of various types of load devices. As an example, and not a limitation, for fast charging systems supporting the USB PD protocol, the preset maximum threshold can be set to 20V or a higher voltage level.

[0088] In some embodiments of this application, the main control module achieves rapid adjustment of the first DC voltage by adjusting the reference voltage VDAC of the error amplifier. Specifically, when it is necessary to increase the first DC voltage to a preset maximum threshold, the main control module reduces the value of the reference voltage VDAC, causing the error amplifier to output a stronger drive signal, increasing the conduction degree of the switching transistor U2, thereby reducing the current flowing through the optocoupler U1, and ultimately causing the transformer T1 to output a higher voltage.

[0089] Step S200: After waiting for a preset time, if a load device is detected connected to the other output ports, the main control module will adjust the first DC voltage to the maximum desired voltage.

[0090] In some embodiments of this application, the preset time is typically set in the range of several hundred milliseconds to several seconds, which ensures both rapid system response and avoids frequent voltage adjustments due to differences in connection timing. Specifically, the length of the preset time needs to strike a balance between response speed and system stability. As an example and not a limitation, when the preset time is set to 1 second, it can cover the typical time window for a user to continuously plug in multiple devices, while not significantly affecting the startup speed of charging a single device.

[0091] In some embodiments of this application, the main control module continuously monitors the connection status of all output ports during the waiting period. It is easy to understand that if a new load device is detected connecting to another output port within a preset time, the main control module will reassess the overall voltage requirements of the system and calculate the maximum expected voltage.

[0092] Specifically, the calculation of the maximum expected voltage is based on the voltage requirements of all connected load devices. As an example, and not a limitation, when the system is connected to three devices that require 5V, 9V, and 15V simultaneously, the main control module selects the maximum value, 15V, as the reference voltage, and then divides it by the maximum duty cycle of the second voltage conversion module (e.g., 0.9) to obtain a maximum expected voltage of approximately 16.7V.

[0093] In some embodiments of this application, the main control module obtains the voltage requirement information of the load device from each slave control module via the I2C communication bus. It is easy to understand that after completing protocol negotiation with the corresponding load device, each slave control module will report the negotiation result to the main control module via the SDA data line, including key information such as device type, supported voltage level, and currently requested charging voltage.

[0094] Step S300: If no load device is detected connected to the other output ports, adjust the first DC voltage to the desired output voltage of the corresponding connected load device.

[0095] In some embodiments of this application, when the system still has only one output port connected to the load device after the preset time has expired, the main control module adopts a single device optimization strategy to precisely adjust the first DC voltage to the optimal input voltage level corresponding to the expected output voltage of the device.

[0096] It's easy to understand that a single-device optimization strategy can maximize system efficiency. As an example, and not a limitation, when the only connected device requires a 9V charging voltage, the main control module adjusts the first DC voltage to 10V, obtained by dividing 9V by the maximum duty cycle (e.g., 0.9). This causes the corresponding second voltage conversion module to operate at a high duty cycle of 0.9, thereby achieving optimal conversion efficiency.

[0097] In some embodiments of this application, the main control module first obtains the specific voltage requirements of the connected load devices. Specifically, the main control module determines the charging voltage value currently requested by the load device by querying the negotiation results of the corresponding fast charging protocol controller. It is easy to understand that different load devices may support multiple voltage levels, and the fast charging protocol controller will select the most suitable voltage for charging based on the actual needs of the device.

[0098] As an example and not a limitation, for load devices that support multiple voltage levels such as 5V, 9V, and 12V, the fast charging protocol controller will select an appropriate voltage level for charging based on the device's current battery status, charging protocol type, and safety considerations. In some embodiments of this application, after obtaining the voltage requirement, the main control module calculates the corresponding desired output voltage and further calculates the first DC voltage level required for the second voltage conversion module to operate at its maximum duty cycle.

[0099] In some embodiments, step S200 specifically includes the following steps: Step S210: When the slave control module detects that a load device has been connected to the corresponding output port, it sends the access status information to the master control module.

[0100] In some embodiments of this application, the slave control module determines the connection status of the load device by continuously monitoring the voltage state of the CC pin. Specifically, when the output port is in an unloaded state, the CC pin typically exhibits a high impedance state or a specific voltage level; when the load device is plugged in, the voltage of the CC pin undergoes a characteristic jump, thereby triggering a device detection event.

[0101] The slave control module integrates a dedicated detection circuit that can accurately identify different types of connection events. As an example, and not a limitation, for a USB Type-C interface, the slave control module can distinguish between different states such as device insertion, device removal, and device type by the voltage change of the CC pin.

[0102] Specifically, once the slave control module confirms the detection of a load device connection, it immediately sends access status information to the master control module via the I2C communication bus. In some embodiments of this application, the access status information includes key data such as port identifier, device type, and connection timestamp, providing necessary basic information for the master control module's subsequent decisions.

[0103] Step S220: The main control module obtains the required output voltage of each connected load device.

[0104] In some embodiments of this application, after receiving a device access notification, the main control module needs to further obtain the specific voltage requirements of each load device. Specifically, the main control module sends a query command to the relevant slave control module via the I2C bus, requesting detailed charging parameters for the load devices.

[0105] It's easy to understand that the voltage requirements of the load device need to be determined through the fast charging protocol negotiation process. As an example, and not a limitation, the slave control module and the load device perform a USB PD protocol handshake via the CC pin to negotiate and determine parameters such as the voltage level supported by the device, the currently requested charging voltage, and the maximum allowable current.

[0106] Specifically, the negotiation process typically includes stages such as capability discovery, power object selection, and contract establishment. In some embodiments of this application, after the slave control module completes the protocol negotiation, it feeds back the negotiation result to the master control module via the I2C bus, including information such as the output voltage value currently requested by the device, a negotiation success flag, and the expected power requirements.

[0107] Step S230: The main control module obtains the maximum value of the output voltage required by each load device and divides it by the maximum duty cycle of the second voltage conversion module to obtain the maximum expected voltage.

[0108] In some embodiments of this application, the main control module analyzes and processes all collected voltage demand information and determines the maximum voltage demand value through a comparison algorithm. Specifically, the main control module traverses the voltage demand list, compares the voltage requirements of each device one by one, and finally determines the highest voltage value as the system's reference voltage.

[0109] It's easy to understand that choosing the maximum voltage value as the benchmark ensures that all devices receive a sufficient voltage supply. As an example, and not a limitation, in the aforementioned list of voltage requirements ("5V, 12V, 9V"), the main control module will select 12V as the maximum voltage value.

[0110] Specifically, the formula for calculating the maximum expected voltage is: Maximum expected voltage = Maximum output voltage requirement / Maximum duty cycle. In some embodiments of this application, the maximum duty cycle is a preset design parameter of the second voltage conversion module, typically set between 0.8 and 0.95, representing the upper limit of the duty cycle at which the module can operate stably.

[0111] It's easy to understand that by dividing the maximum output voltage requirement by the maximum duty cycle, one can calculate the input voltage level needed for the device with the highest voltage requirement to operate at optimal efficiency. As an example, and not a limitation, when the maximum output voltage requirement is 12V and the maximum duty cycle is 0.9, the maximum expected voltage is 12V / 0.9 ≈ 13.3V.

[0112] Step S240: The main control module adjusts the first DC voltage to the maximum desired voltage.

[0113] In some embodiments of this application, the main control module achieves precise control of the first DC voltage by adjusting the reference voltage of the error amplifier. Specifically, the main control module controls the operating state of the optocoupler through the OPTO pin, thereby adjusting the output voltage of the first voltage conversion module. In some embodiments of this application, when it is necessary to increase the first DC voltage, the main control module reduces the current flowing through the optocoupler, reducing its impact on the transformer's operating state, thereby raising the output voltage to the target level.

[0114] In some embodiments, step S300 specifically includes the following steps: Step S310: The main control module obtains the output voltage required by the connected load device and divides it by the maximum duty cycle of the second voltage conversion module to obtain the desired output voltage.

[0115] In some embodiments of this application, for single-device connection scenarios, the main control module employs a specially optimized voltage calculation strategy. Specifically, the main control module first obtains the voltage requirement information of the only connected device via the I2C bus to determine the specific charging voltage value currently requested by the device. As an example and not a limitation, when the only device requires a 9V charging voltage, the main control module does not need to consider the voltage requirements of other devices and can provide the optimal input voltage configuration specifically for that device.

[0116] Specifically, the formula for calculating the desired output voltage is similar to that in step S230, but only applies to a single device: Desired output voltage = Load device voltage requirement / Maximum duty cycle. In some embodiments of this application, the desired output voltage obtained through this calculation method enables the corresponding second voltage conversion module to operate at a preset maximum duty cycle.

[0117] It's easy to understand that the maximum duty cycle operating state represents the optimal efficiency point of the second voltage conversion module. As an example, and not a limitation, when the device requires 9V and the maximum duty cycle is 0.9, the desired output voltage is 9V / 0.9 = 10V. At this point, the operating duty cycle of the second voltage conversion module is 9V / 10V = 0.9, achieving optimal efficiency.

[0118] Step S320: The main control module adjusts the first DC voltage to the desired output voltage.

[0119] Specifically, the main control module precisely adjusts the output voltage of the first voltage conversion module according to the expected output voltage value calculated in step S310, so that it is stable at the optimal value.

[0120] It's easy to understand that single-device optimization requires higher precision compared to multi-device scenarios. As an example, and not a limitation, the main control module can employ finer voltage adjustment steps and more stringent stability criteria to ensure the second voltage conversion module operates stably at the target duty cycle. Specifically, after voltage adjustment, the corresponding second voltage conversion module will operate at its maximum duty cycle, achieving optimal conversion efficiency, while effectively controlling the overall system power consumption and heat generation.

[0121] Unlike existing technologies, the embodiments of the present invention can dynamically adjust the input voltage according to the actual load requirements, so that the output DC-DC power supply works in the optimal duty cycle state, significantly improving the overall conversion efficiency of the system, solving the problem of low efficiency caused by fixed input voltage in existing multi-port fast charging adapters, and meeting the requirements of the new energy efficiency standards.

[0122] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and not to limit them; under the concept of this application, the technical features of the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other variations of different aspects of this application as described above. For the sake of brevity, they are not provided in detail; although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or make equivalent substitutions for some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A fast charging control circuit, characterized in that, include: Several output ports are used to connect load devices; The first voltage conversion module is used to convert AC voltage into a first DC voltage; Several second voltage conversion modules are respectively connected to the first voltage conversion module and the corresponding output port, and are used to convert the first DC voltage into the corresponding second DC voltage; Several control modules are connected to corresponding output ports and corresponding second voltage conversion modules, respectively; the control modules are used to adjust the second DC voltage to the output voltage required by the corresponding connected load device; The main control module is connected to the first voltage conversion module and is used to adjust the first DC voltage to the maximum desired voltage. The maximum desired voltage is obtained by dividing the maximum value of the output voltage required by each load device connected to the corresponding output port by the maximum duty cycle of the second voltage conversion module. The plurality of control modules includes one of the main control modules.

2. The circuit according to claim 1, characterized in that, The first voltage conversion module includes a transformer T1, a diode D1, and a resistor R. LED And optocoupler U1; The primary side of transformer T1 is connected to the AC voltage, the first terminal of the secondary side of transformer T1 is connected to the anode of diode D1, and the cathode of diode D1 is connected to resistor R. LED The first end of the transformer T1 is connected to the voltage input terminal of the corresponding second voltage conversion module and the voltage input terminal of the corresponding control module, and the second end of the secondary side of the transformer T1 is connected to the reference ground. The resistor R LED The second end is connected to the anode of the optocoupler U1, and the cathode of the optocoupler U1 is connected to the optocoupler feedback pin of the main control module.

3. The circuit according to claim 1, characterized in that, The main control module includes an error amplifier OP, a switching transistor U2, resistors R1 and R2, control switches S1 and S2, current source IS1, and current source IS2. The drain of the switching transistor U2 is connected to the controlled terminal of the first voltage conversion module, the gate of the switching transistor U2 is connected to the output terminal of the error amplifier OP, and the source of the switching transistor U2 is connected to the reference ground. The non-inverting input terminal of the error amplifier OP is connected to the second terminal of the resistor R1 and the first terminal of the resistor R2. The first terminal of the resistor R1 is connected to the output terminal of the first voltage conversion module. The inverting input terminal of the error amplifier OP is connected to the reference voltage. The second terminal of the resistor R2 is connected to the reference ground. The positive terminal of the current source IS1 is connected to the power supply voltage, the negative terminal of the current source IS1 is connected to the first terminal of the control switch S1, the second terminal of the control switch S1 is connected to the first terminal of the control switch S2 and the feedback output terminal of the corresponding second voltage conversion module, the second terminal of the control switch S2 is connected to the positive terminal of the current source IS2, and the negative terminal of the current source IS2 is connected to the reference ground.

4. The circuit according to claim 1, characterized in that, The second voltage conversion module includes capacitor C1, capacitor C2, resistor R3, resistor R4, and a voltage conversion unit; The first terminal of capacitor C1 is connected to the output terminal of the first voltage conversion module and the positive input terminal of the voltage conversion unit, and capacitor C1 and the negative input terminal of the voltage conversion unit are connected to reference ground. The positive output terminal of the voltage conversion unit is connected to the first terminal of the capacitor C2, the first terminal of the resistor R3, and the output voltage pin of the corresponding output port. The negative output terminal of the voltage conversion unit is connected to the second terminal of the capacitor C2, the second terminal of the resistor R4, and the ground pin of the corresponding output port. The second terminal of the resistor R3 is connected to the first terminal of the resistor R4 and the voltage feedback pin of the corresponding control module.

5. The circuit according to claim 1, characterized in that, The plurality of control modules includes one master control module and the rest are slave control modules. The master control module is communicatively connected to the slave control modules through clock signal lines and data signal lines.

6. The circuit according to claim 5, characterized in that, The slave control module includes control switch S1, control switch S2, current source IS1, and current source IS2. The positive terminal of the current source IS1 is connected to the power supply voltage, the negative terminal of the current source IS1 is connected to the first terminal of the control switch S1, the second terminal of the control switch S1 is connected to the first terminal of the control switch S2 and the feedback output terminal of the corresponding second voltage conversion module, the second terminal of the control switch S2 is connected to the positive terminal of the current source IS2, and the negative terminal of the current source IS2 is connected to the reference ground.

7. A charger, characterized in that, include: The fast charging control circuit as described in any one of claims 1-6.

8. A control method applied to the fast charging control circuit as described in any one of claims 1-6, characterized in that, include: When any output port is connected to a load device, the main control module will adjust the first DC voltage to the preset maximum threshold. After waiting for a preset time, if a load device is detected connected to the other output ports, the main control module will adjust the first DC voltage to the maximum desired voltage. If no load device is detected connected to the other output ports, the first DC voltage is adjusted to the desired output voltage of the corresponding connected load device.

9. The method according to claim 8, characterized in that, If a load device is detected connected to any of the other output ports, the main control module adjusts the first DC voltage to the maximum desired voltage, including: When the slave control module detects that a load device has been connected to the corresponding output port, it sends the connection status information to the master control module. The main control module acquires the output voltage required by each connected load device; The main control module obtains the maximum value of the output voltage required by each load device and divides it by the maximum duty cycle of the second voltage conversion module to obtain the maximum expected voltage. The main control module adjusts the first DC voltage to the maximum desired voltage.

10. The method according to claim 8, characterized in that, If no load device is detected connected to any of the other output ports, adjusting the first DC voltage to the desired output voltage of the corresponding connected load device includes: The main control module obtains the output voltage required by the connected load device and divides it by the maximum duty cycle of the second voltage conversion module to obtain the desired output voltage. The main control module adjusts the first DC voltage to the desired output voltage.

Images