A fast charging switching circuit and method based on dual-interface plugging and unplugging detection

Abstract

The present invention discloses a fast charging switching circuit and method based on dual-interface plug-and-unplug detection. The circuit includes a power supply terminal, a rectifying and transforming circuit, a control system, a USB Type-A interface, and a USB Type-C interface. A filtering and degaussing circuit is connected between the rectifying and transforming circuit and the USB Type-A interface and the USB Type-C interface. A switching unit is connected to the USB Type-A interface and the USB Type-C interface. The control system is connected between the rectifying and transforming circuit and the USB Type-A interface and the USB Type-C interface. The control system includes a fast charging control unit and a plug-and-unplug detection unit. The method of the present invention is applied to the above circuit. The present invention can save the circuit design cost, expand the range of detectable devices, make the scenario switching more efficient and time-saving, and better meet the fast charging requirements.

Description

Technical Field

[0001] The present invention relates to the technical field of fast charging, and specifically, to a fast charging switching circuit based on dual-interface plug and unplug detection and a fast charging switching method applied to this circuit.

Background Art

[0002] In recent years, with the development of fast charging technology, more and more USB interface forms have emerged. As the latest interface form technology, TYPE-C is powerful and convenient to use. In the current situation where there are more and more electronic devices, sometimes it is necessary to charge multiple electronic devices. In order to better accommodate different USB interface forms, there are already many dual-port charging solutions on the market. However, some detections in existing solutions are not flexible enough, the action logic cannot adapt to the actual situation, and the efficiency is low. And those with higher efficiency have complex internal circuits, resulting in higher manufacturing costs for the required hardware circuits.

[0003] In the technical solution of the prior art one, ports A and C are not independent. When both dual-port NMOS are turned on, only 5V charging is supported. To re-awaken fast charging, plugging and unplugging are required, which is not flexible enough to switch according to the corresponding situation.

[0004] In the technical solution of the prior art two, ports A and C are independent, and the dual ports work separately. When both ports are inserted, fast charging can be performed on both ports A and C, but the manufacturing cost is high.

[0005] Therefore, for some small-current devices, if the corresponding NMOS is turned off when inserted, the insertion is not easily detected; in the case where both dual-port NMOS are turned on, only 5V charging can be performed, and the load cannot be detected flexibly; the cost is high and the occupied space is large.

Summary of the Invention

[0006] The main object of the present invention is to provide a fast charging switching circuit based on dual-interface plug and unplug detection that can save circuit design costs, expand the range of detectable devices, switch scenarios more efficiently and time-savingly, and better meet the fast charging requirements.

[0007] Another object of the present invention is to provide a fast charging switching method for a fast charging switching circuit based on dual-interface plug and unplug detection that can save circuit design costs, expand the range of detectable devices, switch scenarios more efficiently and time-savingly, and better meet the fast charging requirements.

[0008] To achieve the above main purpose, a fast charging switching circuit based on dual-interface plugging and unplugging detection provided by the present invention includes a power supply terminal, a rectifying and transforming circuit, a control system, a USB Type-A interface, and a USB Type-C interface. The power supply terminal inputs a power supply voltage to the rectifying and transforming circuit. A filtering and degaussing circuit is connected between the rectifying and transforming circuit and the USB Type-A interface and the USB Type-C interface. A switching unit is connected to the USB Type-A interface and the USB Type-C interface. The control system is connected between the rectifying and transforming circuit and the USB Type-A interface and the USB Type-C interface. The control system includes a fast charging control unit and a plugging and unplugging detection unit. The plugging and unplugging detection unit respectively detects the device plugging and unplugging signals of the USB Type-A interface and the USB Type-C interface. The fast charging control unit generates a switching control signal according to the detected device plugging and unplugging signals. The fast charging control unit sends a switching signal to the switching circuit according to the switching control signal to conduct / turn off the charging path from the power supply terminal to the USB Type-A interface and the USB Type-C interface.

[0009] A further solution is that the fast charging control unit includes a first fast charging control circuit and a second fast charging control circuit. The plugging and unplugging detection unit includes a first plugging and unplugging detection circuit and a second plugging and unplugging detection circuit. The switching unit includes a first switching circuit and a second switching circuit. The first plugging and unplugging detection circuit detects the device plugging and unplugging signal of the USB Type-A interface. The first fast charging control circuit generates a first switching control signal according to the detected device plugging and unplugging signal of the USB Type-A interface. The first fast charging control circuit sends a switching signal to the first switching circuit according to the first switching control signal to conduct / turn off the charging path from the power supply terminal to the USB Type-A interface. The second plugging and unplugging detection circuit detects the device plugging and unplugging signal of the USB Type-C interface. The second fast charging control circuit generates a second switching control signal according to the detected device plugging and unplugging signal of the USB Type-C interface. The second fast charging control circuit sends a switching signal to the second switching circuit according to the second switching control signal to conduct / turn off the charging path from the power supply terminal to the USB Type-C interface.

[0010] An even further solution is that both the first switching circuit and the second switching circuit are MOS transistor switching circuits.

[0011] A further solution is that the first fast charging control circuit includes a first fast charging protocol control circuit, a first MTK fast charging control unit, a first DCP protocol circuit, and a first port control circuit. The enabling ends of the first fast charging protocol control circuit, the first MTK fast charging control unit, and the first DCP protocol circuit are respectively electrically connected to the first plug and unplug detection circuit through the first port control circuit.

[0012] A further solution is that the second fast charging control circuit includes a second fast charging protocol control circuit, a second MTK fast charging control unit, a second DCP protocol circuit, a second port control circuit, and a PD control circuit. The enabling ends of the second fast charging protocol control circuit, the second MTK fast charging control unit, the second DCP protocol circuit, and the PD control circuit are respectively electrically connected to the second plug and unplug detection circuit through the second port control circuit.

[0013] It can be seen that in the present invention, the USB Type-A interface is always open, and the USB Type-C interface also remains open when establishing a CC connection; in the normal charging state, the switch ground circuits of the two interfaces can be kept open, which is beneficial to detecting the insertion of small-current devices and improves the application universality; the two interfaces respectively support multiple fast charging protocols and have excellent protocol compatibility; when the MOS tube switch circuits of both interfaces are turned on, when one interface is lightly loaded, the other interface can still resume fast charging; it can save the circuit design cost and the cost is relatively low; it can expand the range of detectable devices; the scenario switching is more efficient and time-saving, and can meet the fast charging requirements as much as possible.

[0014] Therefore, compared with the traditional solution, the device detection ability of the present invention is more sensitive. Under the condition of permission, both interfaces are kept open as much as possible, which can more accurately detect small-current devices, and can more effectively and time-savingly complete the state switching for some charging scenarios.

[0015] To achieve the above-mentioned another object, the present invention also provides a fast charging switching method for a fast charging switching circuit based on dual-interface plugging and unplugging detection, which is applied to a fast charging switching circuit based on dual-interface plugging and unplugging detection. The method includes: after determining that the system is in the powered-on state, real-time detecting whether the loaded states and charging modes of the two interfaces change. If they change, then judging whether the current states of the MOS transistor switch circuits of the two interfaces are in the on state. If the MOS transistor switch circuits of the two interfaces are both in the on state, then judging whether the current state of the USB Type-A interface is in the heavy load state. After determining that the current state of the USB Type-A interface is in the heavy load state, judging whether the current state of the USB Type-C interface is in the heavy load state. If the current states of both interfaces are in the heavy load state, then turning off the fast charging enable, performing a simulated USB plugging and unplugging on the two interfaces, and entering the normal charging state; if it is determined that the current state of the USB Type-A interface is not in the heavy load state, then judging whether the current states of the two interfaces are in the light load state. If not, then it can be determined that the USB Type-C interface is in the heavy load state, then judging whether the fast charging enable is turned on. If not, then turning off the MOS transistor switch circuit of the USB Type-C interface, and controlling to turn on the fast charging enable, performing a simulated USB plugging and unplugging on the USB Type-C interface, and performing a turn-on and turn-off operation on its MOS transistor switch circuit to prompt the USB Type-C interface to re-apply for fast charging. Among them, when the USB Type-C interface enters the fast charging state, the USB Type-A interface remains in the normally open state.

[0016] A further solution is that after determining that the current state of the USB Type-A interface is in the heavy load state, judging whether the current state of the USB Type-C interface is in the heavy load state. If the current state of the USB Type-C interface is not in the heavy load state, then judging whether the current states of the two interfaces are in the light load state. If not, then judging whether the fast charging enable is turned on. If not, then turning off the MOS transistor switch circuit of the USB Type-A interface, and controlling to turn on the fast charging enable, performing a simulated USB plugging and unplugging on the USB Type-A interface, and performing a turn-on and turn-off operation on its MOS transistor switch circuit to prompt the USB Type-A interface to re-apply for fast charging. When the USB Type-A interface enters the fast charging state, if the USB Type-C interface does not establish a CC connection, then turning off the USB Type-C interface.

[0017] A further solution is that after determining that the USB Type-C interface is in an overloaded state, if fast charging is enabled, it is determined whether the USB Type-C interface enters fast charging. If so, the USB Type-C interface enters the fast charging state; after determining that the current state of the USB Type-A interface is in an overloaded state, if fast charging is enabled, it is determined whether the USB Type-A interface enters fast charging. If so, the USB Type-A interface enters the fast charging state.

[0018] A further solution is that when determining whether the MOS transistor switch circuits of the two interfaces are in an open state, if only the MOS transistor switch circuit of a single USB Type-A interface or USB Type-C interface is in an open state, it is determined whether the single USB Type-A interface or USB Type-C interface is in a light load state. If so, the interface that has been closed is opened so that both interfaces are in an open state.

[0019] A further solution is that if both interfaces are in a light load state and both interfaces are in an open state, it is determined whether the USB Type-C interface establishes a CC connection. If not, the USB Type-C interface is closed; if it is determined that the USB Type-C interface establishes a CC connection, the current state is maintained, that is, both interfaces remain in an open state.

[0020] It can be seen that the method of the present invention adds a normally open function for the corresponding port, which can more accurately judge the plugging and unplugging of various devices in different scenarios; the opening and closing conditions of the MOS switch circuit make the device more flexible in switching between normal charging and fast charging; any single AC port supports multiple fast charging protocols, and when both ports are inserted and overloaded, it is automatically recognized and reduced to 5V charging, which can limit the power to ensure safety; when one interface enters a light load, the interface in a heavy load can resume fast charging, and both interfaces' MOS switch circuits are kept normally open under conditions allowing, to ensure the plugging and unplugging judgment of different characteristic devices can be recognized.

[0021] Therefore, compared with the traditional scheme, the present invention is more sensitive in detecting the device capabilities. Both interfaces are kept normally open as much as possible under conditions allowing, which can more accurately detect small current devices, and for some charging scenarios, the state switching can be completed more effectively and time-saving.

Description of the Drawings

[0022] Figure 1 It is a schematic diagram of an embodiment of a fast charging switching circuit based on dual-interface plugging and unplugging detection of the present invention.

[0023] Figure 2 It is a circuit schematic diagram of a first fast charging control circuit in an embodiment of a fast charging switching circuit based on dual-interface plugging and unplugging detection of the present invention.

[0024] Figure 3 It is the circuit schematic diagram of the second fast charging control circuit in an embodiment of a fast charging switching circuit based on dual-interface plugging and unplugging detection according to the present invention.

[0025] Figure 4 It is the circuit schematic diagram of the USB Type-A interface, the first switch circuit, and the first plugging and unplugging detection circuit in an embodiment of a fast charging switching circuit based on dual-interface plugging and unplugging detection according to the present invention.

[0026] Figure 5 It is the circuit schematic diagram of the USB Type-C interface and the second switch circuit in an embodiment of a fast charging switching circuit based on dual-interface plugging and unplugging detection according to the present invention.

[0027] Figure 6 It is the circuit schematic diagram of the first plugging and unplugging detection circuit and the second plugging and unplugging detection circuit in an embodiment of a fast charging switching circuit based on dual-interface plugging and unplugging detection according to the present invention.

[0028] Figure 7 It is the circuit schematic diagram of the first switch circuit in an embodiment of a fast charging switching circuit based on dual-interface plugging and unplugging detection according to the present invention.

[0029] Figure 8 It is the circuit schematic diagram of the current detection circuit in an embodiment of a fast charging switching circuit based on dual-interface plugging and unplugging detection according to the present invention.

[0030] Figure 9 It is the working flow block diagram of an embodiment of the fast charging switching method of a fast charging switching circuit based on dual-interface plugging and unplugging detection according to the present invention.

Detailed implementation manners

[0031] In order to make the objectives, technical solutions, and advantages of the invention more clear and understandable, 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 limited to the present invention.

[0032] An embodiment of a fast charging switching circuit based on dual-interface plugging and unplugging detection:

[0033] Refer to Figure 1, a fast charging switching circuit based on dual-interface plug-and-unplug detection of the present invention includes a power supply terminal 100, a rectification and transformation circuit 10, a control system 20, a USB Type-A interface 1, and a USB Type-C interface 2. The power supply terminal 100 inputs a power supply voltage to the rectification and transformation circuit 10. A filter and degaussing circuit 30 is connected between the rectification and transformation circuit 10 and the USB Type-A interface 1 and the USB Type-C interface 2. A switching unit is connected to the USB Type-A interface 1 and the USB Type-C interface 2. The control system 20 is connected between the rectification and transformation circuit 10 and the USB Type-A interface 1 and the USB Type-C interface 2.

[0034] In this embodiment, the control system 20 includes a fast charging control unit 40 and a plug-and-unplug detection unit 50. The plug-and-unplug detection unit 50 respectively detects the device plug-and-unplug signals of the USB Type-A interface 1 and the USB Type-C interface 2. The fast charging control unit 40 generates a switching control signal according to the detected device plug-and-unplug signals. The fast charging control unit 40 sends a switching signal to the switching circuit according to the switching control signal to turn on / off the charging path from the power supply terminal 100 to the USB Type-A interface 1 and the USB Type-C interface 2. It can be seen that the control system 20 is mainly divided into a fast charging control part and a plug-and-unplug detection part: the insertion detection part varies according to different actual chips. The USB Type-A interface 1 can be divided into DCP insertion detection and external interrupt insertion detection, and the USB Type-C interface 2 follows the Type-C connection and disconnection rules to perform insertion detection and judgment.

[0035] In this embodiment, the rectification and transformation circuit 10 can be any conventional rectification and transformation circuit, and the filter and degaussing circuit 30 can be any corresponding filter and degaussing circuit 30, or it can also be an integration of a filter circuit and a degaussing circuit. The power supply input of this embodiment can be an adapter or a vehicle charger power supply, etc. After being transformed and rectified by the rectification and transformation circuit 10, it is sent to the filter and degaussing circuit 30 for filtering and degaussing, and finally becomes a stable DC power supply.

[0036] In this embodiment, the fast charging control unit 40 includes a first fast charging control circuit 41 and a second fast charging control circuit 42. The plug and unplug detection unit 50 includes a first plug and unplug detection circuit and a second plug and unplug detection circuit. The switch unit includes a first switch circuit 61 and a second switch circuit 62. The first plug and unplug detection circuit detects the device plug and unplug signal of the USB Type-A interface 1. The first fast charging control circuit 41 generates a first switch control signal according to the detected device plug and unplug signal of the USB Type-A interface 1. The first fast charging control circuit 41 sends a switch signal to the first switch circuit 61 according to the first switch control signal to turn on / off the charging path from the power supply terminal 100 to the USB Type-A interface 1. The second plug and unplug detection circuit detects the device plug and unplug signal of the USB Type-C interface 2. The second fast charging control circuit 42 generates a second switch control signal according to the detected device plug and unplug signal of the USB Type-C interface 2. The second fast charging control circuit 42 sends a switch signal to the second switch circuit 62 according to the second switch control signal to turn on / off the charging path from the power supply terminal 100 to the USB Type-C interface 2.

[0037] See Figure 2 , the first fast charging control circuit 41 includes a first fast charging protocol control circuit 411, a first MTK fast charging control unit 412, a first DCP protocol circuit 413, and a first port control circuit 414. The enable terminals of the first fast charging protocol control circuit 411, the first MTK fast charging control unit 412, and the first DCP protocol circuit 413 are respectively electrically connected to the first plug and unplug detection circuit through the first port control circuit 414. Specifically, the first DCP protocol circuit 413 is mainly for BC1.2 and APPLE; the first fast charging protocol control circuit 411 is mainly for fast charging using DP and DM for communication such as QC2.0 / QC3.0 / AFC / FCP / SCP / SFCP, etc.; the first MTK fast charging control circuit 412 is mainly for the MTK protocol using current to communicate through VBUS.

[0038] See Figure 3, the second fast charging control circuit 42 includes a second fast charging protocol control circuit 421, a second MTK fast charging control unit 422, a second DCP protocol circuit 423, a second port control circuit 423, and a PD control circuit 425. The enable terminals of the second fast charging protocol control circuit 421, the second MTK fast charging control unit 422, the second DCP protocol circuit 423, and the PD control circuit 425 are respectively electrically connected to the second plug and unplug detection circuit through the second port control circuit 423. Specifically, the second DCP protocol circuit 423 is mainly for BC1.2 and APPLE; the second fast charging protocol control circuit 421 is mainly for fast charging using DP and DM for communication such as QC2.0 / QC3.0 / AFC / FCP / SCP / SFCP, etc.; the second MTK fast charging control circuit 422 is mainly for the MTK protocol that uses current to communicate through VBUS; the PD control circuit 425 operates on the terminal and the charger and uses the CC / communication protocol, which is the PD protocol, including PD2.0 / 3.0.

[0039] See Figures 4 to 8 , the switching unit further includes a current detection circuit. The ground terminal of the USB Type-A interface 1 is connected to a first sampling resistor R1, and the ground terminal of the USB Type-C interface 2 is connected to a second sampling resistor R2. The current detection circuit respectively detects the differential pressure signals of the first sampling resistor R1 and the second sampling resistor R2. In this embodiment, the operational amplifier method is used for current detection, which can make the current detection more accurate. Among them, the current detection circuit is divided into a power supply terminal 100 current detection circuit 204 and a ground terminal unplug current detection circuit 205 (using a differential operation circuit).

[0040] Among them, both the first plug and unplug detection circuit and the second plug and unplug detection circuit include a power supply terminal 100 plug and unplug detection circuit 201 and a ground terminal unplug detection circuit 202. Among them, see Figure 6 , the power supply terminal 100 plug and unplug detection circuit 201 includes a resistor R3 and a diode D1. One end of the resistor R3 is connected to the power supply terminal 100 VCC, the other end of the resistor R3 is connected to the positive electrode of the diode D1, and the negative electrode of the diode D1 is connected to VOUT; the ground terminal unplug detection circuit 202 includes a resistor R4, a resistor R5, and a MOS transistor Q1. The source electrode of the MOS transistor Q1 is connected to one end of the resistor R5, and both ends of the resistor R4 are connected between the drain electrode of the MOS transistor Q1 and the other end of the resistor R5.

[0041] See Figure 7 , the first switching circuit 61 and the second switching circuit 62 are both MOS transistor switching circuits. Using MOS transistors as switching elements, they also operate in two states: cutoff or conduction.

[0042] It can be seen that in the present invention, the USB Type-A interface 1 is always on, and when the USB Type-C interface 2 establishes a CC connection, it also remains always on; in the normal charging state, the switching circuits of the two interfaces can be kept in the always-on state, which is beneficial to detecting the insertion of small-current devices and improves the application universality; the two interfaces respectively support multiple fast-charging protocols and have excellent protocol compatibility; when the MOSFET switching circuits of both interfaces are turned on, when one interface is lightly loaded, the other interface can still resume fast charging; it can save the circuit design cost and has a low cost; it can expand the range of detectable devices; the scenario switching is more efficient and time-saving, and can meet the fast-charging requirements as much as possible.

[0043] Therefore, compared with the traditional solution, the device detection ability of the present invention is more sensitive. When conditions permit, both interfaces are kept as always on as much as possible, which can more accurately detect small-current devices, and for some charging scenarios, the state switching can be completed more effectively and time-saving.

[0044] An embodiment of the fast-charging switching method for a fast-charging switching circuit based on dual-interface plugging and unplugging detection:

[0045] A fast-charging switching method for a fast-charging switching circuit based on dual-interface plugging and unplugging detection, which is applied to the above fast-charging switching circuit. The method includes: after determining that the system is in the powered-on state, detecting in real time whether the loaded states and charging modes of the two interfaces change. If they change, then judge whether the current states of the MOSFET switching circuits of the two interfaces are in the on state. If the MOSFET switching circuits of both interfaces are in the on state, then judge whether the current state of the USB Type-A interface 1 is in the heavily loaded state. After determining that the current state of the USB Type-A interface 1 is in the heavily loaded state, judge whether the current state of the USB Type-C interface 2 is in the heavily loaded state. If the current states of both interfaces are in the heavily loaded state, then turn off the fast-charging enable, perform a simulated USB plugging and unplugging on the two interfaces, and enter the normal charging state; if it is determined that the current state of the USB Type-A interface 1 is not in the heavily loaded state, then judge whether the current states of the two interfaces are in the lightly loaded state. If not, then it can be determined that the USB Type-C interface 2 is in the heavily loaded state, then judge whether the fast-charging enable is turned on. If not, then turn off the MOSFET switching circuit of the USB Type-C interface 2, and control to turn on the fast-charging enable, perform a simulated USB plugging and unplugging on the USB Type-C interface 2, and perform a turn-on and turn-off operation on its MOSFET switching circuit to prompt the USB Type-C interface 2 to re-apply for fast charging. Among them, when the USB Type-C interface 2 enters the fast-charging state, the USB Type-A interface 1 remains always on.

[0046] In this embodiment, the change in the loaded state of the interface can be detected from the current threshold. When it is greater than the current threshold, it is considered a transition from light load to heavy load. When it is less than the current threshold, it is a transition from heavy load to light load; the charging mode is the fast charging protocol triggered by the current charging port to determine which fast charging mode it is, or whether it is in the fast charging mode or the normal charging mode, that is, to monitor the loaded state of the dual ports and the triggered fast charging in real time.

[0047] In this embodiment, light load means within the load capacity range of the circuit. When it is lower than a certain load threshold, it is determined as light load. This threshold can vary according to actual applications and can be determined by the percentage of the output power in the total power. When it is lower than this value, it is light load; heavy load means when it is higher than this threshold, it is determined as heavy load. In this application, the light load / heavy load can also be judged according to the magnitude of the current drawn by the load device.

[0048] Further, after determining that the current state of the USB Type-A interface 1 is the heavy load state, judge whether the current state of the USB Type-C interface 2 is the heavy load state. If the current state of the USB Type-C interface 2 is not the heavy load state, then judge whether the current states of the two interfaces are the light load states. If not, then judge whether the fast charging enable is turned on. If not, then turn off the MOS tube switching circuit of the USB Type-A interface 1 and control the turn-on of the fast charging enable, perform a simulated USB plug and unplug operation on the USB Type-A interface 1, and perform a turn-on and turn-off operation on its MOS tube switching circuit to prompt the USB Type-A interface 1 to re-apply for fast charging. When the USB Type-A interface 1 enters the fast charging state, if the USB Type-C interface 2 does not establish a CC connection, then turn off the USB Type-C interface 2.

[0049] Further, after determining that the USB Type-C interface 2 is in the heavy load state, if the fast charging enable has been turned on, then judge whether the USB Type-C interface 2 enters the fast charging state. If so, the USB Type-C interface 2 enters the fast charging state; after determining that the current state of the USB Type-A interface 1 is the heavy load state, if the fast charging enable has been turned on, then judge whether the USB Type-A interface 1 enters the fast charging state. If so, the USB Type-A interface 1 enters the fast charging state.

[0050] Further, when judging whether the current states of the MOS tube switching circuits of the two interfaces are in the on state, if only the MOS tube switching circuit of a single USB Type-A interface 1 or USB Type-C interface 2 is in the on state, then judge whether the single USB Type-A interface 1 or USB Type-C interface 2 is in the light load state. If so, then turn on the interface that has been turned off to make both interfaces in the on state.

[0051] Further, if both interfaces are in a light load state and both interfaces are in an enabled state, determine whether the USB Type-C interface 2 has established a CC connection. If not, turn off the USB Type-C interface 2; if it is determined that the USB Type-C interface 2 has established a CC connection, maintain the current state, that is, both interfaces remain in the enabled state.

[0052] Specifically, Table 1 shows the dual-port states and fast charge switch states corresponding to different scenarios:

[0053]

[0054]

[0055] Table 1

[0056] In practical applications, refer to Figure 9 , the method includes the following steps:

[0057] Step 1, after the system is powered on, it is in a resident state. In the resident state, the MOS tube switch circuit of the USB Type-A interface 1 is turned on when powered on.

[0058] Step 2, determine whether the load states and charging modes (normal charging / fast charging) of the two interfaces have changed. If they have changed, execute Step 3; otherwise, execute Step 16.

[0059] Step 3, determine the opening status of the MOS tube switch circuits of the two interfaces in the current state. Among them, the steps corresponding to the opening status of the MOS tube switch circuits of the two interfaces are as follows: (1). If the MOS tube switch circuit of a single USB Type-A interface 1 or USB Type-C interface 2 is in an enabled state, execute Step 12. (2). If the MOS tube switch circuits of both interfaces are open, execute Step 4.

[0060] Step 4, determine whether the current state of the USB Type-A interface 1 is a heavy load. After it is determined that the current state of the USB Type-A interface 1 is a heavy load state, execute Step 5; if it is determined that the current state of the USB Type-A interface 1 is not a heavy load state, execute Step 7.

[0061] Step 5, determine whether the current state of the USB Type-C interface 2 is a heavy load state. If the current state of the USB Type-C interface 2 is not a heavy load state, execute Step 7; after it is determined that the current state of the USB Type-A interface 1 is a heavy load state, execute Step 6.

[0062] Step 6, if the current states of both interfaces are overload states, turn off the fast charging enable, perform simulated plug and unplug switching of the NMOS for both interfaces, and enter the dual-port normal charging state, then execute Step 16.

[0063] Step 7, determine whether the current states of both interfaces are light load states. If so, execute Step 14; otherwise, execute Step 8.

[0064] Among them, in Step 7, if it is determined that the current states of both interfaces are not light load states, it can be determined that one of the USB Type-A interface 1 or the USB Type-C interface 2 is in an overload state.

[0065] Step 8, determine whether the fast charging enable is turned on. If not, execute Step 9; if so, execute Step 10.

[0066] Step 9, then turn off the MOS tube switch circuit of the USB Type-A interface 1, control the turn-on of the fast charging enable, perform simulated USB plug and unplug on the overload port USB Type-A interface 1, and perform a turn-on and turn-off operation on its MOS tube switch circuit to prompt the USB Type-A interface 1 to re-apply for fast charging. Then, jump to Step 16. Among them, when the USB Type-A interface 1 enters the fast charging state, if the USB Type-C interface 2 does not establish a CC connection, turn off the USB Type-C interface 2.

[0067] Step 10, determine whether the overload port enters fast charging. If it enters fast charging, execute Step 11; otherwise, jump to Step 16.

[0068] Among them, in Step 10, after determining that the USB Type-C interface 2 is in an overload state, if the fast charging enable has been turned on, determine whether the USB Type-C interface 2 enters fast charging. If so, the USB Type-C interface 2 enters the fast charging state; after determining that the current state of the USB Type-A interface 1 is in an overload state, if the fast charging enable has been turned on, determine whether the USB Type-A interface 1 enters fast charging. If so, the USB Type-A interface 1 enters the fast charging state.

[0069] Step 11, when the overload port enters the fast charging state, turn off the light load port, and then jump to Step 16.

[0070] Step 12, if only the MOS tube switch circuit of a single USB Type-A interface 1 or USB Type-C interface 2 is in the on state, determine whether this interface is in a light load state. If it is in a light load state, jump to Step 13; otherwise, jump to Step 16.

[0071] Step 13, when only one interface is open and this interface is lightly loaded, open the interface that has been closed so that both interfaces are in the open state, and then jump to Step 16. Among them, if you want to open USB Type-C interface 2, it must be in the state where CC is connected. If CC is not connected, directly jump to Step 16.

[0072] Step 14, if both interfaces are in the lightly loaded state and both interfaces are in the open state, determine whether USB Type-C interface 2 has established a CC connection. If it is determined that USB Type-C interface 2 has established a CC connection, maintain the current state; otherwise, jump to Step 15.

[0073] Step 15, close USB Type-C interface 2. Jump to Step 16.

[0074] Step 16, permanent state. Any branch finally jumps to this state. After that, jump to Step 1, and continuously detect the loaded state and charging mode in this state.

[0075] Thus, it can be seen that the method of the present invention adds the normally open function of the corresponding port, and can more accurately judge the plugging and unplugging of various devices in different scenarios; the opening and closing conditions of the MOS switch circuit make the device more flexible in switching between general charging and fast charging; any single AC port supports multiple fast charging protocols. When both ports are inserted and in the heavily loaded state, it will automatically recognize and reduce to 5V charging, which can limit the power to ensure safety; when one interface enters the lightly loaded state, the interface in the heavily loaded state can resume fast charging. Under the condition of permission, the MOS switch circuits of both interfaces are kept normally open to ensure that the insertion of different characteristic devices can be recognized and judged.

[0076] Therefore, compared with the traditional scheme, the present invention is more sensitive in detecting the capabilities of devices. Under the condition of permission, both interfaces are preferably kept normally open, which can more accurately detect small-current devices, and can more effectively and time-savingly complete the state switching for some charging scenarios. It mainly has the following characteristics:

[0077] 1. The USB Type-A interface is set to be normally open and is powered on and opened immediately. The only scenario for closing is when the USB Type-C interface enters fast charging.

[0078] 2. The scenarios for closing the USB Type-C interface are: (1) CC is not connected; (2) The USB Type-A interface requests fast charging; in other scenarios, the USB Type-C interface remains normally open.

[0079] 3. Software controls to simulate plugging and unplugging, eliminating the need for manual physical plugging and unplugging, saving time and being more efficient.

[0080] 4. Any single port supports multiple fast charging modes. When charging with two ports simultaneously, the output voltage automatically drops to 5V. When one of the interfaces becomes lightly loaded, if the heavily loaded port is simulated to be unplugged and replugged, the heavily loaded port can automatically resume fast charging.

[0081] 5. Single-channel voltage transformation, with branching after the control system 20, which saves costs and makes the hardware circuit simpler. It can be externally equipped with dual switches for separate control, providing more flexible control.

[0082] 6. The detection and judgment conditions for heavy and light loads cover a wide range, enabling effective detection of devices with different electrical characteristics. Limitations can be imposed in terms of current value, fast charging high voltage, DCP and CC connection status, fast charging mode, etc.

[0083] It should be noted that the above are only the preferred embodiments of the present invention, but the design concept of the invention is not limited thereto. Any non-substantive modifications made using this concept also fall within the protection scope of the present invention.

Claims

1. A fast charging switching method for a fast charging switching circuit based on dual-interface plugging and unplugging detection, characterized in that, the fast charging switching circuit includes: a power supply terminal, a rectifying and transforming circuit, a control system, a USB Type-A interface, and a USB Type-C interface. The power supply terminal inputs a power supply voltage to the rectifying and transforming circuit. A filtering and degaussing circuit is connected between the rectifying and transforming circuit and the USB Type-A interface and the USB Type-C interface. A switching unit is connected to the USB Type-A interface and the USB Type-C interface. The control system is connected between the rectifying and transforming circuit and the USB Type-A interface and the USB Type-C interface; the control system includes a fast charging control unit and a plugging and unplugging detection unit. The plugging and unplugging detection unit respectively detects the device plugging and unplugging signals of the USB Type-A interface and the USB Type-C interface. The fast charging control unit generates a switching control signal according to the detected device plugging and unplugging signals. The fast charging control unit sends a switching signal to the switching unit according to the switching control signal to conduct / close the charging path from the power supply terminal to the USB Type-A interface and the USB Type-C interface; the method includes: after determining that the system is in the power-on state, real-time detect whether the loaded state and the charging mode of the two interfaces change. If they change, then judge whether the current state of the MOS transistor switching circuits of the two interfaces is in the on state. If the MOS transistor switching circuits of both interfaces are in the on state, then judge whether the current state of the USB Type-A interface is in the heavy load state. After determining that the current state of the USB Type-A interface is in the heavy load state, judge whether the current state of the USB Type-C interface is in the heavy load state. If the current states of both interfaces are in the heavy load state, then turn off the fast charging enable, perform a simulated USB plugging and unplugging on the two interfaces, and enter the normal charging state; if it is determined that the current state of the USB Type-A interface is not in the heavy load state, then judge whether the current states of the two interfaces are in the light load state. If not, it can be determined that the USB Type-C interface is in the heavy load state. Then judge whether the fast charging enable is turned on. If not, then turn off the MOS transistor switching circuit of the USB Type-C interface, and control to turn on the fast charging enable, perform a simulated USB plugging and unplugging on the USB Type-C interface, and perform a turn-on and turn-off operation on its MOS transistor switching circuit to prompt the USB Type-C interface to re-apply for fast charging. Among them, when the USB Type-C interface enters the fast charging state, the USB Type-A interface remains in the normally open state.

2. The fast charging switching method according to claim 1, characterized in that: The fast charging control unit includes a first fast charging control circuit and a second fast charging control circuit. The plugging and unplugging detection unit includes a first plugging and unplugging detection circuit and a second plugging and unplugging detection circuit. The switching unit includes a first switching circuit and a second switching circuit. The first plugging and unplugging detection circuit detects the device plugging and unplugging signal of the USB Type-A interface. The first fast charging control circuit generates a first switching control signal according to the detected device plugging and unplugging signal of the USB Type-A interface. The first fast charging control circuit sends a switching signal to the first switching circuit according to the first switching control signal to turn on / off the charging path from the power supply terminal to the USB Type-A interface; The second plugging and unplugging detection circuit detects the device plugging and unplugging signal of the USB Type-C interface. The second fast charging control circuit generates a second switching control signal according to the detected device plugging and unplugging signal of the USB Type-C interface. The second fast charging control circuit sends a switching signal to the second switching circuit according to the second switching control signal to turn on / off the charging path from the power supply terminal to the USB Type-C interface.

3. The fast charging switching method according to claim 2, characterized in that: Both the first switching circuit and the second switching circuit are MOS transistor switching circuits.

4. The fast charging switching method according to claim 2 or 3, characterized in that: The first fast charging control circuit includes a first fast charging protocol control circuit, a first MTK fast charging control unit, a first DCP protocol circuit, and a first port control circuit. The enable terminals of the first fast charging protocol control circuit, the first MTK fast charging control unit, and the first DCP protocol circuit are respectively electrically connected to the first plugging and unplugging detection circuit through the first port control circuit.

5. The fast charging switching method according to claim 2 or 3, characterized in that: The second fast charging control circuit includes a second fast charging protocol control circuit, a second MTK fast charging control unit, a second DCP protocol circuit, a second port control circuit, and a PD control circuit. The enable terminals of the second fast charging protocol control circuit, the second MTK fast charging control unit, the second DCP protocol circuit, and the PD control circuit are respectively electrically connected to the second plugging and unplugging detection circuit through the second port control circuit.

6. The fast charging switching method according to claim 1, characterized in that: After determining that the current state of the USB Type-A interface is the overload state, it is judged whether the current state of the USB Type-C interface is the overload state. If the current state of the USB Type-C interface is not the overload state, it is judged whether the current states of the two interfaces are the light load states. If not, it is judged whether the fast charging enable is turned on. If not, the MOS tube switching circuit of the USB Type-A interface is turned off, and the fast charging enable is controlled to be turned on. The USB Type-A interface is simulated to be plugged and unplugged, and its MOS tube switching circuit is executed for turning on and off operations to prompt the USB Type-A interface to re-apply for fast charging. When the USB Type-A interface enters the fast charging state, if the USB Type-C interface does not establish a CC connection, the USB Type-C interface is turned off.

7. The fast charging switching method according to claim 6, characterized in that: After determining that the USB Type-C interface is in the overload state, if the fast charging enable has been turned on, it is judged whether the USB Type-C interface enters the fast charging state. If so, the USB Type-C interface enters the fast charging state; After determining that the current state of the USB Type-A interface is the overload state, if the fast charging enable has been turned on, it is judged whether the USB Type-A interface enters the fast charging state. If so, the USB Type-A interface enters the fast charging state.

8. The fast charging switching method according to claim 6, characterized in that: When judging whether the current states of the MOS tube switching circuits of the two interfaces are in the on state, if only the MOS tube switching circuit of a single USB Type-A interface or the USB Type-C interface is in the on state, it is judged whether the single USB Type-A interface or the USB Type-C interface is in the light load state. If so, the interface that has been turned off is turned on to make both interfaces in the on state.

9. The fast charging switching method according to claim 6, characterized in that: If both interfaces are in the light load state and both interfaces are in the on state, it is judged whether the USB Type-C interface establishes a CC connection. If not, the USB Type-C interface is turned off; if it is determined that the USB Type-C interface establishes a CC connection, the current state is maintained, that is, both interfaces remain in the on state.

Images