A power path switching circuit, method, all-in-one device, and medium

Abstract

This invention relates to the field of power bank and adapter combo devices, specifically a power supply path switching circuit, method, combo device, and medium, including a lithium battery, an AC input module, an AC input detection module, a first buck-boost module, a first MOSFET, a switching module, a second buck-boost module, an output module, and a main control module. The AC input module is connected to the lithium battery through the first MOSFET and the first buck-boost module. Both the AC input module and the lithium battery are connected to the output module through the switching module and the second buck-boost module. The charging path of the lithium battery is independently controlled by the first MOSFET. In AC direct supply mode, the battery charging circuit is shut off, avoiding continuous charging and discharging stress on the battery in scenarios where charging and discharging are simultaneous. By adding an independent power supply path from the AC input module to the output module, and mutually exclusive selection between this power supply path and the battery power supply path through the switching module, high-voltage signals can be prevented from being mistakenly applied to the lithium battery, effectively improving device safety.

Description

Technical Field

[0001] This invention relates to the field of mobile power supply and adapter combination technology, and in particular to a power supply path switching circuit, method, combination device and medium. Background Technology

[0002] Currently, integrated devices combining power bank and AC adapter functions are becoming increasingly common in the market. These devices typically use simple MOSFET switches or diodes to switch paths during the switching between multiple modes such as AC input power supply, battery power supply, and battery charging. This means that when the device is in adapter mode, the higher voltage of the AC input can be directly applied to both ends of the lithium battery cell due to switch failure, logic abnormalities, etc., causing safety accidents such as overcharging, overheating, bulging, or even fire. Furthermore, the existing switching logic cannot achieve mutual exclusion between the AC input path and the battery power supply path, making it difficult to eliminate the risk of high voltage accidentally touching the battery cell at the architectural level. This fails to meet the market's demand for high safety and long lifespan in two-in-one devices.

[0003] Therefore, it is of great importance to those skilled in the art to design a power supply path switching circuit, method, two-in-one device, and medium that can effectively isolate the battery in adapter mode. Summary of the Invention

[0004] This invention provides a power supply path switching circuit, method, two-in-one device, and medium that can effectively isolate the battery in adapter mode, in order to solve the problem of battery lacking effective isolation and having high voltage mischarging in adapter mode.

[0005] This invention discloses a power supply path switching circuit for use in a power bank and adapter combo device. The circuit comprises: a lithium battery, an AC input module, an AC input detection module, a first buck-boost module, a first MOSFET, a switching module, a second buck-boost module, an output module, and a main control module. The AC input module is used to connect to external AC power. The output terminal of the AC input module is connected to the source of the first MOSFET and the first input terminal of the switching module. The drain of the first MOSFET is connected to the input terminal of the first buck-boost module. The output terminal of the first buck-boost module is connected to the lithium battery. The lithium battery is connected to the second input terminal of the switching module. The output terminal of the switching module is connected to the input terminal of the second buck-boost module. The output terminal of the second buck-boost module is connected to the output module. The output module is used to connect to an external load.

[0006] The main control module is connected to the AC input detection module and the second buck-boost module, respectively, and is used to acquire AC input signals and load access signals. The main control module is connected to the gate of the first MOS transistor and the control terminal of the switching module, respectively, and is used to control the first MOS transistor and the switching module to switch power supply paths according to the AC input signals and load access signals.

[0007] Optionally, the switching module includes a second MOSFET, a third MOSFET, a fourth MOSFET, and a fifth MOSFET. The gates of the second MOSFET, the third MOSFET, the fourth MOSFET, and the fifth MOSFET are all connected to the main control module. The drain of the second MOSFET is connected to the second output terminal of the AC input module. The source of the second MOSFET is connected to the source of the third MOSFET. The drain of the fourth MOSFET is connected to the lithium battery. The source of the fourth MOSFET is connected to the source of the fifth MOSFET. The drains of the third MOSFET and the fifth MOSFET are both connected to the input terminal of the second buck-boost module.

[0008] Optionally, a sixth MOS transistor and a seventh MOS transistor are further provided between the switching module and the main control module. The gates of the sixth MOS transistor and the seventh MOS transistor are both connected to the main control module. The sources of the sixth MOS transistor and the seventh MOS transistor are both grounded. The drain of the sixth MOS transistor is connected to the gate of the second MOS transistor and the gate of the third MOS transistor, respectively. The drain of the seventh MOS transistor is connected to the gate of the fourth MOS transistor and the gate of the fifth MOS transistor, respectively.

[0009] Optionally, it also includes a lithium battery protection module, which is disposed between the lithium battery and the switching module for overcurrent, overvoltage and short circuit protection.

[0010] Optionally, the output module includes a Type-C port and a Type-A port, and the second buck-boost module is connected to the CC pin of the Type-C port, the VBUS pin of the Type-C port, and the BVBUSA pin of the Type-A port, respectively, to detect the load access signal.

[0011] Optionally, the main control module is configured with an I2C signal terminal and a detection terminal. The detection terminal of the main control module is connected to the AC input detection module to obtain the AC input signal, and the I2C signal terminal of the main control module is connected to the second buck-boost module to obtain the load access signal.

[0012] To address the problems existing in the prior art, the present invention also provides a power supply path switching method, which is implemented through any of the power supply path switching circuits described above, specifically including the following steps: It has three preset working modes: AC charging lithium battery, AC charging load, and lithium battery charging load. Acquire the current AC input signal and load access signal, and determine the current operating mode based on the current AC input signal and load access signal; When the current working mode is AC lithium battery charging mode, the first MOS transistor is turned on, and the first and second input terminals of the switching module are both disconnected from the output terminal of the switching module. When the current operating mode is AC charging mode, the first MOSFET is turned off, and the first input terminal of the switching module is turned on to the output terminal of the switching module. When the current working mode is lithium battery charging load, the first MOS transistor is controlled to disconnect, and the second output terminal of the switching module is controlled to be connected to the output terminal of the switching module.

[0013] Optionally, the following steps are also included: When no AC input signal is detected but a load connection signal is detected, the current working mode is determined to be lithium battery charging load mode. When an AC input signal is detected but no load is connected, the current working mode is determined to be AC ​​lithium battery charging mode. When an AC input signal and a load connection signal are detected, the current operating mode is determined to be AC ​​charging load mode.

[0014] To address the problems existing in the prior art, the present invention also provides a two-in-one device that combines a power bank and an adapter. The device includes a housing and a circuit board, wherein the circuit board is disposed within the housing and the circuit board is provided with a power supply path switching circuit as described above.

[0015] To address the problems existing in the prior art, the present invention also provides a computer-readable storage medium, wherein the medium stores a computer program, which, when executed by a processor, causes the processor to perform the steps of the method described in any of the preceding claims.

[0016] The beneficial effects of the power supply path switching circuit provided in this embodiment of the invention are as follows: the circuit can automatically identify the working scenario of the device and control the on / off state of the first MOSFET and the switching module by acquiring the AC input signal and the load access signal, thereby realizing the automatic switching of modes such as pure battery discharge, AC direct power supply and battery charging; the charging path of the lithium battery is independently controlled by the first MOSFET, and the charging circuit of the battery can be turned off in the AC direct power supply mode, avoiding the battery from continuously bearing charging and discharging stress in the scenario of charging and discharging simultaneously; furthermore, by adding an independent power supply path that directly leads from the AC input module to the output port, and mutually selecting this power supply path and the battery power supply path through the switching module, it is possible to effectively prevent high voltage signals from being mistakenly applied to the lithium battery, effectively avoid safety risks such as overcharging and overheating, and extend the cycle life of the lithium battery. Attached Figure Description

[0017] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. In the accompanying drawings: Figure 1 This is a system block diagram of the power supply path switching circuit in an embodiment of the present invention; Figure 2 This is a circuit diagram of the switching module in an embodiment of the present invention; Figure 3 This is a circuit diagram of the AC input module in an embodiment of the present invention; Figure 4 This is a circuit diagram of the first buck-boost module in an embodiment of the present invention; Figure 5 This is a circuit diagram of the lithium battery protection module in an embodiment of the present invention; Figure 6 This is a circuit diagram of the main control module in an embodiment of the present invention; Figure 7 This is a circuit diagram of the AC input detection module in an embodiment of the present invention; Figure 8 This is a circuit diagram of the output module in an embodiment of the present invention; Figure 9 This is a circuit diagram of the second buck-boost module in an embodiment of the present invention; Figure 10 This is the flowchart of the power supply path switching method in the embodiment of the present invention. Figure 1 ; Figure 11 This is the flowchart of the power supply path switching method in the embodiment of the present invention. Figure 2 .

[0018] The labels for the attached figures are as follows: 1. Lithium battery; 2. AC input module; 3. AC input detection module; 4. First buck-boost module; 5. First MOSFET; 6. Switching module; 7. Second buck-boost module; 8. Output module; 9. Main control module; 10. Lithium battery protection module; 61. Second MOSFET; 62. Third MOSFET; 63. Fourth MOSFET; 64. Fifth MOSFET; 65. Sixth MOSFET; 66. Seventh MOSFET; 81. USB-C interface; 82. USB-A interface. Detailed Implementation

[0019] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. The preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0020] like Figures 1 to 9 As shown, the present invention provides a specific embodiment of a power supply path switching circuit.

[0021] A power path switching circuit is applied in a power bank and adapter combo device, referenced. Figures 1 to 9 The power supply path switching circuit includes a lithium battery 1, an AC input module 2, an AC input detection module 3, a first buck-boost module 4, a first MOSFET 5, a switching module 6, a second buck-boost module 7, an output module 8, and a main control module 9. The AC input module 2 is used to connect to external AC mains power. The output terminal of the AC input module 2 is connected to the source (S) of the first MOSFET 5 and the first input terminal of the switching module 6, respectively. The drain (D) of the first MOSFET 5 is connected to the input terminal of the first buck-boost module 4, and the output terminal of the first buck-boost module 4 is connected to the lithium battery 1. The lithium battery 1 is connected to the second input terminal of the switching module 6, and the output terminal of the switching module 6 is connected to the input terminal of the second buck-boost module 7. The output terminal of the second buck-boost module 7 is connected to the output module 8, which is used to connect to an external load.

[0022] The main control module 9 is connected to the AC input detection module 3 and the second buck-boost module 7 respectively, and is used to acquire AC input signals and load access signals. The main control module 9 is connected to the gate G of the first MOS transistor 5 and the control terminal of the switching module 6 respectively, and is used to control the first MOS transistor 5 and the switching module 6 to switch the power supply path according to the AC input signals and load access signals.

[0023] AC input module 2 is an AC-DC conversion module used to convert 90-264V AC power into a stable 22V DC power output. The 22V DC power output by AC input module 2 can be divided into two power supply paths: one path serves as the charging power for a mobile power bank, supplying power to the first buck-boost module 4 through the first MOSFET 5; the other path serves as the power input in adapter mode, directly connected to the switching module 6 to provide power to the subsequent second buck-boost module 7.

[0024] The first MOSFET 5 is a P-type MOSFET connected in series between the AC input module 2 and the first buck-boost module 4. Its gate G level is controlled by the main control module 9 to control the on / off state of the charging path of the lithium battery 1. The first buck-boost module 4 is a charging management circuit that receives the 22V voltage from the AC input module 2 and adjusts it to the voltage and current suitable for charging the lithium battery 1, realizing constant current / constant voltage safe charging of the lithium battery 1. When the first MOSFET 5 is turned off, the loop between the AC input module 2 and the first buck-boost module 4 is broken, and charging of the lithium battery 1 stops. The lithium battery 1 is the energy storage unit of the device. Its positive output terminal (PACK+) is connected to the second input terminal of the switching module 6 as the power supply in the mobile power supply mode. The negative terminal of the lithium battery 1 is connected to the system ground to provide a reference potential for the circuit.

[0025] The switching module 6 is an electronic switch with two inputs and one output. The first input terminal of the switching module 6 receives the 22V voltage from the AC input module 2, and the second input terminal receives the voltage from the lithium battery 1PACK+. The two inputs of the switching module 6 are switched on and off under the control of the main control module 9 to achieve mutual exclusion between the AC input path and the discharge path of the lithium battery 1, so as to avoid the two power supplies simultaneously supplying power to the second step-up / step-down module 7 and prevent high voltage from being mistakenly applied to the lithium battery 1.

[0026] The output module 8 includes a USB-C interface 81 and a USB-A interface 82, which are used to connect to an external load and realize the external charging function. At the same time, the output module 8 can feed back the load access signal to the second buck-boost module 7, thereby feeding back the load access signal to the main control module 9, and then providing a trigger signal for path switching control.

[0027] The second buck-boost module 7 is a buck-boost circuit. Its input terminal receives the B+ voltage output by the switching module 6 and adjusts the input B+ voltage to a charging voltage (such as 5V, 9V, 12V, 15V, 20V, etc.) that is compatible with the external load according to the load access signal (such as the PD protocol handshake result of the USB-C interface 81), and outputs it to the output module 8, thereby providing a suitable power supply for electronic devices of different specifications.

[0028] The AC input detection module 3 is used to monitor in real time whether the AC input module 2 is connected to the mains power and outputs an AC-INT detection signal to the main control module 9. The main control module 9 receives the AC input signal from the AC input detection module 3 and the load access signal fed back by the second buck-boost module 7 to determine the current working scenario of the device. On the other hand, it outputs a control signal according to the judgment result to drive the gate G of the first MOS transistor 5 and the control terminal of the switching module 6 to realize the switching of the power supply path.

[0029] In this embodiment, the control logic of the main control module 9 includes the following three operating modes: 1. Power Bank Mode (No AC Input, Load Received): When the device is not connected to mains power, the AC input detection module 3 outputs a corresponding low-level signal. The main control module 9 determines that there is no AC input. At this time, the main control module 9 controls the first MOSFET 5 to turn off, cutting off the circuit between the AC input module 2 and the first buck-boost module 4. At the same time, it controls the switching module 6 to conduct the discharge path of the lithium battery 1 and turn off the AC input path. The voltage of the lithium battery 1PACK+ is output to the second buck-boost module 7 through the switching module 6. The second buck-boost module 7 adjusts the voltage according to the load requirements and then supplies power to the external load through the output module 8.

[0030] 2. Adapter Mode (AC Input and Load Connection): When the device is connected to AC power and a load is connected, the AC input detection module 3 outputs a corresponding high-level signal. The main control module 9 determines that there is an AC input scenario and simultaneously receives the load connection signal from the second buck-boost module 7. At this time, the main control module 9 controls the first MOSFET 5 to turn off, cutting off the charging path of the lithium battery 1 to prevent simultaneous charging and discharging. Simultaneously, it controls the switching module 6 to turn on the AC input path and turn off the discharge path of the lithium battery 1. The 22V voltage output from the AC input module 2 is directly output to the second buck-boost module 7 via the switching module 6. The second buck-boost module 7 adjusts the voltage according to the load requirements and then supplies power to the external load through the output module 8. In this mode, the lithium battery 1 and the AC input path are mutually exclusive and isolated, preventing high voltage from being mistakenly applied to the lithium battery 1.

[0031] 3. Battery charging mode (AC input present, no load connected): When the device is connected to AC power but no load is connected, the AC input detection module 3 outputs a high-level signal, and the main control module 9 determines that there is an AC input scenario. At the same time, it receives the no-load signal fed back by the second buck-boost module 7. At this time, the main control module 9 controls the switching module 6 to turn off the AC input path and the discharge path of the lithium battery 1. At the same time, it controls the first MOSFET 5 to turn on. The 22V voltage of the AC input module 2 charges the lithium battery 1 through the first MOSFET 5 and the first buck-boost module 4. After charging is completed, the main control module 9 can control the first MOSFET 5 to turn off and stop charging to avoid overcharging.

[0032] In this embodiment, a power supply path switching circuit is designed to automatically realize intelligent switching of charging and discharging and power supply path according to AC input status and load access status. In adapter working mode, the switching module 6 can effectively isolate the lithium battery 1 from the high-voltage power supply path, avoiding the direct application of AC input voltage to the battery cell. This eliminates safety hazards such as overcharging, overheating, and high-voltage accidental contact from the circuit architecture, significantly improving the safety of equipment use. At the same time, the first MOSFET 5 independently controls the on / off of the charging path of the lithium battery 1. When supplying power to the outside, the charging circuit can be turned off, avoiding the battery from continuously bearing charging and discharging stress in the scenario of charging and discharging simultaneously, effectively slowing down cell aging and extending the service life of the lithium battery 1.

[0033] In one embodiment, reference Figures 1 to 9 The switching module 6 includes a second MOSFET 61, a third MOSFET 62, a fourth MOSFET 63, and a fifth MOSFET 64. The gates G of the second MOSFET 61, the third MOSFET 62, the fourth MOSFET 63, and the fifth MOSFET 64 are all connected to the main control module 9. The drain D of the second MOSFET 61 is connected to the second output terminal of the AC input module 2. The source S of the second MOSFET 61 is connected to the source S of the third MOSFET 62. The drain D of the fourth MOSFET 63 is connected to the lithium battery 1. The source S of the fourth MOSFET 63 is connected to the source S of the fifth MOSFET 64. The drains D of the third MOSFET 62 and the fifth MOSFET 64 are both connected to the input terminal of the second buck-boost module 7.

[0034] Specifically, the switching module 6 consists of two pairs of N-channel MOSFETs forming a bidirectional conduction structure to achieve mutual exclusion between the AC input path and the discharge path of the lithium battery 1; that is, the second MOSFET 61 and the third MOSFET 62 form the first set of bidirectional switches to control the power supply path from the AC input module 2 to the second buck-boost module 7; the fourth MOSFET 63 and the fifth MOSFET 64 form the second set of bidirectional switches to control the power supply path from the lithium battery 1 to the second buck-boost module 7.

[0035] In adapter operating mode, the main control module 9 outputs a drive signal to the gates G of the second MOSFET 61 and the third MOSFET 62 to turn them on. The 22V DC power output from the AC input module 2 is then output to the second buck-boost module 7 via the second MOSFET 61 and the third MOSFET 62. At the same time, the main control module 9 outputs a turn-off signal to the gates G of the fourth MOSFET 63 and the fifth MOSFET 64 to turn them off. The discharge path of the lithium battery 1 is cut off, achieving electrical isolation between the lithium battery 1 and the high-voltage AC input path, and preventing the AC voltage from being directly applied to the lithium battery 1 cell.

[0036] In the power bank operating mode, the main control module 9 outputs a drive signal to the gates G of the fourth MOSFET 63 and the fifth MOSFET 64 to turn them on. The voltage output by the lithium battery 1PACK+ is then output to the second buck-boost module 7 via the fourth MOSFET 63 and the fifth MOSFET 64. At the same time, the main control module 9 outputs a turn-off signal to the gates G of the second MOSFET 61 and the third MOSFET 62 to turn them off. The AC input path is cut off, achieving isolation between the battery-powered and AC sides and preventing reverse current from damaging the AC input module 2.

[0037] In this embodiment, the safe isolation and switching between the AC input path and the lithium battery 1 discharge path are achieved by controlling the mutual exclusion of two sets of bidirectional MOSFET switches. This avoids the risk of current backflow and high voltage accidental contact caused by the simultaneous conduction of two power supplies, effectively improving the safety and reliability of the circuit operation.

[0038] In one embodiment, reference Figures 1 to 9 A sixth MOSFET 65 and a seventh MOSFET 66 are also provided between the switching module 6 and the main control module 9. The gate G of the sixth MOSFET 65 and the gate G of the seventh MOSFET 66 are both connected to the main control module 9. The source S of the sixth MOSFET 65 and the source S of the seventh MOSFET 66 are both grounded. The drain D of the sixth MOSFET 65 is connected to the gate G of the second MOSFET 61 and the gate G of the third MOSFET 62, respectively. The drain D of the seventh MOSFET 66 is connected to the gate G of the fourth MOSFET 63 and the gate G of the fifth MOSFET 64, respectively.

[0039] Specifically, the sixth MOSFET 65 and the seventh MOSFET 66 are N-channel MOSFETs, used to realize level conversion and drive isolation between the bidirectional MOSFETs in the main control module 9 and the switching module 6; the main control module 9 indirectly controls the gate G level of the second MOSFET 61, the third MOSFET 62, the fourth MOSFET 63 and the fifth MOSFET 64 in the switching module 6 through the sixth MOSFET 65 and the seventh MOSFET 66, thereby realizing the switching of the power supply path.

[0040] In adapter operating mode, the main control module 9 outputs a high-level drive signal to the gate G of the sixth MOSFET 65, turning on the sixth MOSFET 65. At this time, the gate G of the second MOSFET 61 and the third MOSFET 62 are grounded through the sixth MOSFET 65, pulling down the gate G level and turning on the second MOSFET 61 and the third MOSFET 62. The 22V DC power output from the AC input module 2 is output to the second buck-boost module 7 through the second MOSFET 61 and the third MOSFET 62. At the same time, the main control module 9 outputs a low-level signal to the gate G of the seventh MOSFET 66, turning off the seventh MOSFET 66. The gate G of the fourth MOSFET 63 and the fifth MOSFET 64 remain at a high level and are in the off state. The discharge path of the lithium battery 1 is cut off, realizing the electrical isolation between the lithium battery 1 and the high-voltage AC input path.

[0041] In the power bank operating mode, the main control module 9 outputs a high-level drive signal to the gate G of the seventh MOSFET 66, turning on the seventh MOSFET 66. At this time, the gate G of the fourth MOSFET 63 and the fifth MOSFET 64 are grounded through the seventh MOSFET 66, pulling down the gate G level and turning on the fourth MOSFET 63 and the fifth MOSFET 64. The voltage output by the lithium battery 1PACK+ is output to the second buck-boost module 7 through the fourth MOSFET 63 and the fifth MOSFET 64. At the same time, the main control module 9 outputs a low-level signal to the gate G of the sixth MOSFET 65, turning off the sixth MOSFET 65. The gate G of the second MOSFET 61 and the third MOSFET 62 remain at a high level and are in the off state. The AC input path is cut off to prevent reverse current from damaging the AC input module 2.

[0042] In this embodiment, the main control module 9 uses the sixth MOSFET 65 and the seventh MOSFET 66 as driving switches. The main control module 9 can indirectly control the conduction and cutoff of the bidirectional MOSFET in the switching module 6 through a low-level signal, without having to directly drive the high-voltage side MOSFET. This reduces the driving pressure on the main control module 9 and improves the stability and safety of the circuit. At the same time, this driving method can realize the mutual exclusion control between the AC input path and the discharge path of the lithium battery 1, avoiding the risk of current backflow and high-voltage accidental contact caused by the simultaneous conduction of two power supplies, and further improving the reliability of the circuit operation.

[0043] In one embodiment, reference Figures 1 to 9 The power supply path switching circuit also includes a lithium battery protection module 10, which is located between the lithium battery 1 and the switching module 6 for overcurrent, overvoltage and short circuit protection.

[0044] Specifically, the lithium battery protection module 10 consists of a lithium battery protection chip and dual MOSFETs. The positive output terminal PACK+ of the two series-connected lithium batteries is directly connected to the second input terminal of the switching module 6, while the negative terminal BAT- is connected to the negative circuit of the switching module 6 through the dual MOSFETs of the lithium battery protection module 10. The power supply terminal VDD of the lithium battery protection chip is connected to PACK+, the detection terminal VC is connected to the intermediate cell node, the ground terminal VSS is connected to BAT-, and the current sampling terminal CS is grounded through a sampling resistor for real-time monitoring of battery voltage and circuit current. The OD and OC output terminals of the lithium battery protection chip drive the gates G of two parallel N-channel MOSFETs, respectively. The source S of the MOSFET is connected to BAT-, and the drain D is connected to the subsequent circuit. A diode and a pull-down resistor are connected in series in the gate G circuit. The GATE_BMS signal output by the main control module 9 controls the conduction and turn-off of the MOSFETs.

[0045] During normal operation, the dual MOSFETs of the lithium battery protection module 10 remain in the on state, allowing the current from the lithium battery 1 to flow normally to the switching module 6. When the battery experiences overvoltage, undervoltage, overcurrent, or short-circuit faults, the OD or OC terminal of the lithium battery protection chip outputs a shutdown signal to control the MOSFETs to turn off, cutting off the negative electrode circuit of the lithium battery 1 and preventing the current from continuing to flow, thus protecting the lithium battery 1. The main control module 9 can use the GATE_BMS signal to assist in controlling the MOSFETs and actively cut off the battery circuit in the event of equipment shutdown or fault, further enhancing system safety.

[0046] In this embodiment, by connecting the lithium battery protection module 10 in series between the lithium battery 1 and the switching module 6, the current circuit can be quickly cut off when the battery is in an abnormal state, effectively preventing damage to the lithium battery 1 caused by overcurrent, overvoltage and short circuit faults, thus improving the reliability and safety of the equipment. At the same time, the parallel structure of dual MOSFETs can improve the overcurrent capacity and meet the requirements of high current charging and discharging. Combined with the active control of the main control module 9, a dual protection mechanism of protection chip and main control is realized, further ensuring the safe use of lithium battery 1 in various working modes.

[0047] In one embodiment, reference Figures 1 to 9 The output module 8 includes a USB-C interface 81 and a USB-A interface 82. The second buck-boost module 7 is connected to the CC pin of the USB-C interface 81, the VBUS pin of the USB-C interface 81, and the BVBSA pin of the USB-A interface 82, respectively, to detect the load access signal.

[0048] Specifically, refer to Figures 1 to 9The second buck-boost module 7 uses an IP5385 chip. The VBUS pin and CC1 / CC2 pins of the IP5385 chip are connected to the VBUS power supply pin and CC1 / CC2 configuration pins of the USB-C interface 81, respectively. At the same time, its BVBSA control pin is connected to the BVBSA power supply pin of the USB-A interface 82. When an external load is connected, the IP5385 chip detects the connection status of the Type-C device through the level change of the CC pin and performs a PD / QC fast charging protocol handshake with the device to identify the power supply requirements of the device. Meanwhile, the VBUS and BVBSA pins detect the current or voltage changes in the power supply circuit to determine whether there is a load connected to the Type-C and USB-A interfaces 82, and feed back the load connection signal to the main control module 9.

[0049] In adapter mode, the main control module 9, upon receiving the load connection signal from the second buck-boost module 7, confirms the external load is connected and then controls the switching module 6 to activate the AC input path. This allows the 22V voltage from the AC input module 2 to enter the second buck-boost module 7 via the switching module 6. The IP5385 chip adjusts the output voltage according to load requirements, supplying power to the external load through the USB-C interface 81 and USB-A interface 82. In power bank mode, the main control module 9 similarly controls the switching module 6 to activate the lithium battery 1 discharge path based on the load connection signal. The lithium battery 1 PACK+ voltage enters the second buck-boost module 7 via the switching module 6, and the IP5385 chip provides an appropriate power supply voltage to the external load. When the load is removed, the second buck-boost module 7 detects no load current in the VBUS and BVBUSA circuits and sends a no-load signal back to the main control module 9. Based on this, the main control module 9 controls the switching module 6 to shut off the power supply path, achieving low-power standby.

[0050] In one embodiment, reference Figures 1 to 9 The main control module 9 is equipped with a detection terminal AC-INT, which is connected to the AC input detection module 3 to acquire AC input signals. Specifically, when the AC input module 2 is connected to mains power, the AC input detection module 3 outputs a high level or a specific valid signal to the AC-INT pin; when the AC input module 2 is not connected to mains power, the AC input detection module 3 outputs a low level or an invalid signal. The main control module 9 determines whether the device is currently in an AC input scenario by reading the level state of the AC-INT pin.

[0051] After acquiring the AC input signal, the main control module 9 combines the load access signal fed back by the second buck-boost module 7 to determine the working mode: when the AC input signal is detected to be valid and a load is connected, the main control module 9 controls the switching module 6 to turn on the AC input path and controls the first MOSFET 5 to turn off the charging path of the lithium battery 1, so that the device works in adapter mode; when the AC input signal is detected to be valid but no load is connected, the main control module 9 controls the switching module 6 to turn off the power supply path and controls the first MOSFET 5 to turn on, so that the device works in lithium battery 1 charging mode; when the AC input signal is detected to be invalid, the main control module 9 controls the switching module 6 to turn on the discharge path of the lithium battery 1, so that the device works in power bank mode.

[0052] In this embodiment, by configuring an AC-INT detection terminal on the main control module 9, the signal from the AC input detection module 3 can be directly received, which can quickly and accurately determine the mains power access status and provide a reliable trigger basis for power supply path switching. This connection method simplifies the AC input signal acquisition circuit, eliminates the need for an additional signal conversion module, reduces hardware costs, and ensures the stability of signal transmission. This enables the main control module 9 to respond to changes in the AC input status in a timely manner and realize intelligent switching of multiple modes.

[0053] like Figures 10 to 11 As shown, the present invention also provides a specific embodiment of a power supply path switching method.

[0054] A power supply path switching method is implemented through the aforementioned power supply path switching circuit, as described above. Figure 10 Specifically, it includes the following steps: S1 has three preset working modes: AC charging lithium battery, AC charging load, and lithium battery charging load. S2. Obtain the current AC input signal and load access signal, and determine the current working mode based on the current AC input signal and load access signal; S31. When the current working mode is AC lithium battery charging mode, control the first MOS transistor 5 to turn on, and control the first input terminal and the second input terminal of the switching module 6 to be disconnected from the output terminal of the switching module 6. S32. When the current working mode is AC charging mode, the first MOS transistor 5 is turned off, and the first input terminal of the switching module 6 is connected to the output terminal of the switching module 6. S33. When the current working mode is lithium battery charging load, the first MOS transistor 5 is turned off, and the second output terminal of the switching module 6 is connected to the output terminal of the switching module 6.

[0055] Step S1: The main control module 9 is pre-configured with switching logic for three working modes, namely: AC charging lithium battery mode: The electrical energy output by AC input module 2 is only used to charge lithium battery 1 and is not used to power external loads.

[0056] AC charging load mode: The electrical energy output by AC input module 2 directly powers the external load, while cutting off the charging path of lithium battery 1 to avoid charging and discharging at the same time.

[0057] Lithium battery charging load mode: The external load is powered by lithium battery 1.

[0058] The switching logic for the above three modes is pre-stored in the control program of the main control module 9, and is automatically invoked by the main control module 9 according to the AC input signal and the load access signal.

[0059] In step S2, the main control module 9 obtains the AC input signal through the output terminal AC-INT of the AC input detection module 3 to determine whether the device is connected to the mains power. At the same time, it obtains the load access signal through the VBUS pin of the second buck-boost module 7 (IP5385) and the CC pin of the USB-C interface 81 to determine whether there is an external load connected. Based on the signal combination of the mains power access signal and the load access signal, it determines the current working mode, that is, whether it is AC charging lithium battery mode, AC charging load mode or lithium battery charging load mode.

[0060] In step S31, when the main control module 9 determines that it is in AC charging lithium battery mode, it outputs a turn-on signal to the gate G of the first MOSFET 5 to turn on the first MOSFET 5. At this time, the 22V voltage output by the AC input module 2 is input to the first buck-boost module 4 through the first MOSFET 5. The first buck-boost module 4 adjusts the voltage to the voltage and current suitable for charging the lithium battery 1 to charge the lithium battery 1. At the same time, the main control module 9 outputs a turn-off signal to the gate G of the second MOSFET 61, the third MOSFET 62, the fourth MOSFET 63 and the fifth MOSFET 64 of the switching module 6, so that the first input terminal (AC path) and the second input terminal (lithium battery 1 path) of the switching module 6 are both disconnected from the output terminal B+. Neither the AC input module 2 nor the lithium battery 1 supplies power to the second buck-boost module 7. The device only charges the lithium battery 1 and does not supply power to the external load.

[0061] In step S32, when the main control module 9 determines that it is in AC charging load mode, it outputs a turn-off signal to the gate G of the first MOSFET 5, causing the first MOSFET 5 to turn off, cutting off the circuit between the AC input module 2 and the first buck-boost module 4, and stopping the charging of the lithium battery 1. At the same time, the main control module 9 outputs a conduction signal to the second MOSFET 61 and the third MOSFET 62 of the switching module 6 through the sixth MOSFET 65, so that the 22V voltage of the AC input module 2 is output to the second buck-boost module 7 through the second MOSFET 61 and the third MOSFET 62. The first input terminal and the output terminal of the switching module 6 are turned on, while the path of the lithium battery 1 remains disconnected. The second buck-boost module 7 adjusts the output voltage according to the load demand and supplies power to the external load through the USB-C interface 81 and the USB-A interface 82, realizing direct power supply in adapter mode.

[0062] In step S33, when the main control module 9 determines that the lithium battery charging load mode is activated, it outputs a turn-off signal to the gate G of the first MOSFET 5, causing the first MOSFET 5 to turn off. At the same time, the main control module 9 outputs a turn-on signal to the fourth MOSFET 63 and the fifth MOSFET 64 of the switching module 6 through the seventh MOSFET 66, so that the voltage of the lithium battery 1PACK+ is output to the second buck-boost module 7 through the fourth MOSFET 63 and the fifth MOSFET 64. The second input terminal and the output terminal of the switching module 6 are turned on, while the AC input path remains disconnected. The second buck-boost module 7 adjusts the output voltage according to the load demand and supplies power to the external load through the USB-C interface 81 and the USB-A interface 82, realizing battery power supply in mobile power bank mode.

[0063] In this embodiment, the above steps achieve automatic switching between three working modes. At the same time, the charging path of lithium battery 1 is cut off in AC charging load mode to avoid charging and discharging simultaneously; the AC input path is cut off in lithium battery charging load mode to prevent reverse current from damaging the AC module; and the power supply path is cut off in AC charging lithium battery mode to achieve efficient charging, thereby improving the safety, conversion efficiency and user experience of the device.

[0064] In one embodiment, reference Figure 11 The power supply path switching method also includes the following steps: S21. When no AC input signal is detected and a load connection signal is detected, it is determined that the current working mode is lithium battery charging load mode. S22. When an AC input signal is detected but no load is connected, it is determined that the current working mode is AC charging lithium battery mode. S23. When an AC input signal and a load connection signal are detected, determine the current working mode as AC charging load mode.

[0065] In step S21, the main control module 9 obtains the AC input signal through the AC-INT pin of the AC input detection module 3. When the AC-INT pin is low, it is determined that there is no AC input signal. At the same time, the main control module 9 determines that there is a load connection signal through the VBUS current detection of the second buck-boost module 7 (IP5385) and the handshake status of the CC pin of the USB-C interface 81. At this time, the main control module 9 determines the current working mode as the lithium battery charging load mode.

[0066] In this mode, the main control module 9 controls the first MOSFET 5 to turn off, cutting off the AC charging path; at the same time, it controls the second input terminal (lithium battery 1 path) of the switching module 6 to turn on and the first input terminal (AC path) to turn off. The lithium battery 1PACK+ voltage is output to the second buck-boost module 7 through the switching module 6 to supply power to the external load.

[0067] In step S22, when the AC-INT pin is high, the main control module 9 determines that there is an AC input signal; at the same time, the second buck-boost module 7 does not detect load current, and the Type-C / USB-A interface 82 has no device access handshake signal, which is determined to be no load access signal; at this time, the main control module 9 determines the current working mode as AC charging lithium battery mode.

[0068] In this mode, the main control module 9 controls the first MOSFET 5 to turn on, and the 22V voltage from the AC input module 2 charges the lithium battery 1 through the first MOSFET 5 and the first buck-boost module 4; at the same time, the first and second input terminals of the control switching module 6 are turned off, cutting off the power supply path to the second buck-boost module 7. The device only performs the charging function and does not supply power to the outside.

[0069] Step S23: When the AC-INT pin of the main control module 9 is high, and the second buck-boost module 7 detects the load current and the Type-C / USB-A interface 82 completes the fast charging protocol handshake, the main control module 9 determines that there is an AC input signal and a load access signal, and determines the current working mode as AC charging load mode.

[0070] In this mode, the main control module 9 controls the first MOSFET 5 to turn off, stopping the charging of the lithium battery 1; at the same time, it controls the first input terminal (AC path) of the switching module 6 to be turned on and the second input terminal (lithium battery 1 path) to be turned off. The 22V voltage of the AC input module 2 is directly output to the second buck-boost module 7 through the switching module 6 to power the external load. The lithium battery 1 and the high-voltage AC path are mutually exclusive and isolated.

[0071] In this embodiment, by combining the judgment of AC input signal and load access signal, the three working modes are accurately distinguished, ensuring that the main control module 9 executes the correct control logic in different scenarios. This avoids safety risks such as charging and discharging simultaneously and accidental high voltage contact, and also achieves efficient switching between AC power supply and battery power supply, thereby improving the safety of the device and the user experience.

[0072] It should be understood that the above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit them. Those skilled in the art can modify the technical solutions described in the above embodiments, or make equivalent substitutions for some of the technical features; and all such modifications and substitutions should fall within the protection scope of the appended claims of the present invention.

Claims

1. A power supply path switching circuit, applied in a power bank and adapter combo device, characterized in that, include: The system comprises a lithium battery, an AC input module, an AC input detection module, a first buck-boost module, a first MOSFET, a switching module, a second buck-boost module, an output module, and a main control module. The AC input module is used to connect to external AC power. Its output terminal is connected to the source of the first MOSFET and the first input terminal of the switching module. The drain of the first MOSFET is connected to the input terminal of the first buck-boost module. The output terminal of the first buck-boost module is connected to the lithium battery. The lithium battery is connected to the second input terminal of the switching module. The output terminal of the switching module is connected to the input terminal of the second buck-boost module. The output terminal of the second buck-boost module is connected to the output module. The output module is used to connect to an external load. The main control module is connected to the AC input detection module and the second buck-boost module, respectively, and is used to acquire AC input signals and load access signals. The main control module is connected to the gate of the first MOS transistor and the control terminal of the switching module, respectively, and is used to control the first MOS transistor and the switching module to switch power supply paths according to the AC input signals and load access signals.

2. The power supply path switching circuit according to claim 1, characterized in that, The switching module includes a second MOSFET, a third MOSFET, a fourth MOSFET, and a fifth MOSFET. The gates of the second MOSFET, the third MOSFET, the fourth MOSFET, and the fifth MOSFET are all connected to the main control module. The drain of the second MOSFET is connected to the second output terminal of the AC input module. The source of the second MOSFET is connected to the source of the third MOSFET. The drain of the fourth MOSFET is connected to the lithium battery. The source of the fourth MOSFET is connected to the source of the fifth MOSFET. The drains of the third MOSFET and the fifth MOSFET are both connected to the input terminal of the second buck-boost module.

3. The power supply path switching circuit according to claim 2, characterized in that, A sixth MOS transistor and a seventh MOS transistor are also provided between the switching module and the main control module. The gates of the sixth MOS transistor and the seventh MOS transistor are both connected to the main control module. The sources of the sixth MOS transistor and the seventh MOS transistor are both grounded. The drain of the sixth MOS transistor is connected to the gate of the second MOS transistor and the gate of the third MOS transistor, respectively. The drain of the seventh MOS transistor is connected to the gate of the fourth MOS transistor and the gate of the fifth MOS transistor, respectively.

4. The power supply path switching circuit according to claim 1, characterized in that, It also includes a lithium battery protection module, which is disposed between the lithium battery and the switching module for overcurrent, overvoltage and short circuit protection.

5. The power supply path switching circuit according to claim 1, characterized in that, The output module includes a Type-C port and a Type-A port. The second buck-boost module is connected to the CC pin of the Type-C port, the VBUS pin of the Type-C port, and the BVBUSA pin of the Type-A port, respectively, to detect the load access signal.

6. The power supply path switching circuit according to claim 5, characterized in that, The main control module is equipped with an I2C signal terminal and a detection terminal. The detection terminal of the main control module is connected to the AC input detection module to obtain the AC input signal, and the I2C signal terminal of the main control module is connected to the second buck-boost module to obtain the load access signal.

7. A power supply path switching method, characterized in that, This is achieved through the power supply path switching circuit as described in any one of claims 1-6, specifically including the following steps: It has three preset working modes: AC charging lithium battery, AC charging load, and lithium battery charging load. Acquire the current AC input signal and load access signal, and determine the current operating mode based on the current AC input signal and load access signal; When the current working mode is AC lithium battery charging mode, the first MOS transistor is turned on, and the first and second input terminals of the switching module are both disconnected from the output terminal of the switching module. When the current operating mode is AC charging mode, the first MOSFET is turned off, and the first input terminal of the switching module is turned on to the output terminal of the switching module. When the current working mode is lithium battery charging load, the first MOS transistor is controlled to disconnect, and the second output terminal of the switching module is controlled to be connected to the output terminal of the switching module.

8. The power supply path switching method according to claim 7, characterized in that, It also includes the following steps: When no AC input signal is detected but a load connection signal is detected, the current working mode is determined to be lithium battery charging load mode. When an AC input signal is detected but no load is connected, the current working mode is determined to be AC ​​lithium battery charging mode. When an AC input signal and a load connection signal are detected, the current operating mode is determined to be AC ​​charging load mode.

9. A two-in-one device combining a power bank and an adapter, characterized in that, It includes a housing and a circuit board, the circuit board being disposed within the housing, and the circuit board being provided with a power supply path switching circuit as described in any one of claims 1-6.

10. A computer-readable storage medium, characterized in that, The system contains a computer program that, when executed by a processor, causes the processor to perform the steps of the method as described in any one of claims 7 to 8.

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