Multi-interface USB circuit and charger

Abstract

The embodiment of the utility model discloses a multi-interface USB circuit and a charger. The multi-interface USB circuit comprises a controller, a first type of USB interface, a second type of USB interface, a current sampling circuit, a direct current bus, a switch unit and a standby power supply circuit. And the switch unit can form a current loop with the second-type USB interface and the current sampling circuit. And the controller responds to the charging current flowing through the current loop to meet a standby charging condition, controls the switch unit to disconnect the path of the bus voltage applied to the second type of USB interface and outputs a standby power supply signal. And the standby power supply circuit is used for responding to the standby power supply signal and providing power for an external load based on the second-type USB interface. According to the embodiment of the invention, when the charging current meets the standby charging condition, the mode that the bus voltage is supplied to the external load for charging is switched into the mode that the standby power supply circuit is supplied to the external load for charging, so that the external load with small current can be fully charged.

Description

TECHNICAL FIELD

[0001] The embodiment of the utility model relates to USB interface technical field, concretely relates to a kind of multi-interface USB circuit and charger. BACKGROUND

[0002] The charger provided by the related art supports the insertion of multiple types of USB interface devices and supports an intelligent power scheduling algorithm to schedule power among different types of USB interface devices. A USB-C interface device is configured with a CC pin, and the charger communicates with the USB-C interface device based on the CC pin to detect the plugging and charging conditions of the device. However, a USB-A interface device is not configured with a CC pin, and the charger cannot detect the plugging and charging conditions of the device in the same way as the USB-C interface device. Typically, when the charging current is less than a preset threshold, it is determined that the USB-A interface device is in a full-charge state. When the USB-A interface device is in the full-charge state, the charger schedules the power originally provided to the USB-A interface device to the USB-C interface device for use according to the intelligent power scheduling algorithm.

[0003] This approach can cause the following problems: when the USB-A interface device is a low-power device, the charging current is smaller than the preset threshold, and at this time, the USB-A interface device is not in the full-charge state. According to the above approach, the charger stops providing power to such low-power USB-A interface devices for charging, which causes such low-power USB-A interface devices to be unable to be fully charged. UTILITY MODEL CONTENT

[0004] To solve the above technical problems, the embodiment of the utility model provides a multi-interface USB circuit and charger for solving the problem that the related art cannot improve the charging capacity of external loads.

[0005] In a first aspect, the embodiments of the present application provide a multi-interface USB circuit, comprising: a controller, a first type of USB interface, a second type of USB interface, a current sampling circuit, a DC bus, a switching unit and a standby power supply circuit. The first type of USB interface is electrically connected to the controller, and the first type of USB interface is a USB interface supporting detection of device insertion based on a CC pin; the second type of USB interface is electrically connected to the controller, and the second type of USB interface is a USB interface not supporting detection of device insertion based on a CC pin; the current sampling circuit is electrically connected to the second type of USB interface and the controller respectively; the DC bus is used for transmitting a bus voltage; the switching unit is electrically connected to the controller, the first type of USB interface, the second type of USB interface and the DC bus respectively, and the switching unit forms a current loop with the second type of USB interface and the current sampling circuit in response to insertion of an external load into the second type of USB interface; the controller controls the switching unit to disconnect the path of the bus voltage applied to the second type of USB interface and outputs a standby power supply signal in response to that the charging current flowing through the current loop meets standby charging conditions; and the standby power supply circuit is electrically connected to the second type of USB interface and the controller respectively, and is used for providing power supply to the external load based on the second type of USB interface in response to the standby power supply signal.

[0006] Optionally, the switching unit comprises: a first switching circuit and a second switching circuit, the first switching circuit is electrically connected to the controller and the first type of USB interface respectively, and is used for applying the bus voltage to the first type of USB interface in a first switching state and disconnecting the path of the bus voltage applied to the first type of USB interface in a second switching state; and the second switching circuit is electrically connected to the controller and the second type of USB interface respectively, and is used for applying the bus voltage to the second type of USB interface in a third switching state and disconnecting the path of the bus voltage applied to the second type of USB interface in a fourth switching state.

[0007] Optionally, the first type of USB interface comprises a first power pin; the first switching circuit comprises a first NMOS tube, the drain of the first NMOS tube is applied with the bus voltage, the source is electrically connected to the first power pin, and the gate is electrically connected to the controller.

[0008] Optionally, the second type of USB interface comprises a second power pin; the second switching circuit comprises a second NMOS tube, the drain of the second NMOS tube is applied with the bus voltage, the source is electrically connected to the second power pin, and the gate is electrically connected to the controller.

[0009] Optionally, the current sampling circuit comprises a sampling resistor, one end of the sampling resistor is electrically connected to the second power pin, the other end of the sampling resistor is grounded, and the controller is electrically connected to both ends of the sampling resistor.

[0010] Optionally, the standby power supply circuit is a low-power power supply chip, the low-power power supply chip comprises a power input end, an enable end and a power output end, the power input end is applied with the bus voltage, the enable end is electrically connected to the controller, and the power output end is electrically connected to the second power pin.

[0011] Optionally, the first type of USB interface is a USB-C interface circuit, and the second type of USB interface is a USB-A interface circuit.

[0012] Optionally, the multi-interface USB circuit further comprises a bleeder circuit, the bleeder circuit is electrically connected to the DC bus and the controller respectively, and is used to bleed interference signals flowing through the DC bus in response to the control of the controller.

[0013] Optionally, the bleeder circuit comprises a current-limiting voltage-dividing circuit and a bleeder switch, the current-limiting voltage-dividing circuit is electrically connected to the DC bus, and the bleeder switch is electrically connected to the current-limiting voltage-dividing circuit and the controller respectively, and is used to bleed interference signals flowing through the DC bus in response to the control of the controller.

[0014] In a first aspect, the embodiments of the present application provide a charger, comprising a step-down circuit and a multi-interface USB circuit, the step-down circuit is used to provide a bus voltage, and a DC bus of the multi-interface USB circuit is electrically connected to the step-down circuit.

[0015] The power switch unit provided by the embodiments of the present application has the beneficial effects that when the charging current meets the standby charging condition, the charging mode from charging the external load by the bus voltage is switched to the charging mode of charging the external load by the standby power supply circuit, so that not only the external load with large current can be fully charged, but also the external load with small current can be fully charged. BRIEF DESCRIPTION OF DRAWINGS

[0016] One or more embodiments are illustrated by way of example in the drawings that are for illustrative purposes only, and these illustrative examples do not constitute a limitation on the embodiments, elements having the same reference numerals in the drawings represent similar elements, unless otherwise specified, the drawings do not constitute a proportional limitation.

[0017] Figure 1 The circuit structure schematic diagram of the charger provided by the first related technology;

[0018] Figure 2A schematic diagram of the circuit structure of a charger provided for the second related technology.

[0019] Figure 3 A schematic diagram of the circuit structure of a charger provided in an embodiment of this application;

[0020] Figure 4 A schematic diagram of the circuit structure of a multi-interface USB circuit provided in an embodiment of this application;

[0021] Figure 5 A circuit structure diagram of a multi-interface USB circuit provided for another embodiment of this application, wherein the switching unit includes a first switching circuit and a second switching circuit;

[0022] Figure 6 A schematic diagram of the specific circuit structure of a multi-interface USB circuit provided in this application embodiment;

[0023] Figure 7 for Figure 4 The circuit structure diagram of the standby power supply circuit is shown below;

[0024] Figure 8 The present application provides a circuit structure diagram of a multi-interface USB circuit according to another embodiment of the present application, wherein the multi-interface USB circuit further includes a discharge circuit;

[0025] Figure 9 The present invention provides a schematic diagram of the circuit structure of a multi-interface USB circuit according to another embodiment of the present application, wherein the discharge circuit includes a current limiting voltage divider circuit and a discharge switch. Detailed Implementation

[0026] To facilitate understanding of this utility model, a more detailed description is provided below with reference to the accompanying drawings and specific embodiments. It should be noted that when an element is described as being "fixed to" another element, it can be directly on the other element, or one or more intermediate elements may exist between them. When an element is described as being "electrically connected" to another element, it can be directly connected to the other element, or one or more intermediate elements may exist between them. The terms "upper," "lower," "inner," "outer," "bottom," etc., used in this specification indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. Furthermore, the terms "first," "second," "third," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0027] Unless otherwise defined, all technical and scientific terms used in this specification have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the invention. The term "and / or" as used in this specification includes any and all combinations of one or more of the associated listed items. Furthermore, technical features involved in the different embodiments of this invention described below may be combined with each other as long as they do not conflict with each other.

[0028] With the development of fast charging technology, electronic devices are demanding increasingly higher power from chargers. This necessitates designing AC-to-DC converter modules to support higher power outputs, which often leads to larger chargers. When chargers have multiple USB ports, supporting various USB devices, more AC-to-DC converter modules or increased power output are required to accommodate the multiple USB ports, further increasing the size of chargers supporting multiple USB ports. To reduce the size of such chargers, a smart power scheduling algorithm is employed. This algorithm controls multiple USB devices to share the same bus voltage or energy provided by the same AC-to-DC converter module. This eliminates the need for multiple AC-to-DC converter modules or a single, larger module to output higher power, thus reducing the size and weight of the charger.

[0029] For example, a charger might be designed with three USB ports: two USB-C and one USB-A. The USB-C ports support 100W of power output, and the USB ports support 18W of power output. The AC-to-DC converter module in such a charger would need to output 100*2 + 18 = 218W of power. However, by employing a smart power scheduling algorithm, the AC-to-DC converter module could be designed to output 100W of power while still meeting the power requirements of multiple USB ports.

[0030] Although the relevant technology uses intelligent power scheduling algorithms to flexibly allocate power among multiple USB ports, it can still meet the power requirements of USB ports without adding multiple AC to DC circuit modules or designing a larger size for a single AC to DC circuit module to output higher power. However, the constraint to achieving the above goal is that the relevant technology needs to know the device plugging and unplugging status and charging status of each USB port.

[0031] The USB-C interface is provided with a CC pin, and the charger can communicate with the USB-C interface device based on the CC pin of the USB-C interface to determine the plug-in state and charging state of the device. However, the USB-A interface or the USB-B interface does not have a CC pin. In order to realize the detection of the plug-in state and the charging state of the device, the related art adopts the following two methods for implementation, as follows:

[0032] 1. The related art is as follows:

[0033] Please refer to Figure 1 The charger provided by the related art includes a floating charging circuit 11, a first resistor 12, a first switch tube 13, a first USB-A interface 14, and a first control module 15.

[0034] The floating charging circuit 11 provides a voltage at a node Vout. When no external load is inserted into the first USB-A interface 14, the first control module 15 detects a high level at the node Vout, controls the first switch tube 13 to enter an off state, and the bus voltage 16 cannot be provided to the first USB-A interface 14. When the external load is inserted into the first USB-A interface 14, the first control module 15 detects a low level at the node Vout, controls the first switch tube 13 to enter an on state, and the bus voltage 16 is transmitted to the external load based on the first USB-A interface 14. When the current flowing through the first resistor 13 is less than a preset threshold value, the first control module 15 considers that the external device has been pulled out or has entered a full state, controls the first switch tube 13 to enter an off state, and schedules the bus voltage 16 to other USB interfaces.

[0035] 2. Another related art is as follows:

[0036] Please refer to Figure 2 The charger provided by the related art includes a second resistor 21, a second switch tube 22, a second USB-A interface 23, and a second control module 24.

[0037] The bus voltage 16 is directly applied to the second USB-A interface 23. When no external load is inserted into the second USB-A interface 23, the second control module 24 detects a low level at a node AGnd, controls the second switch tube 22 to enter an off state. When the external load is inserted into the second USB-A interface 23, the second control module 24 detects a high level at the node AGnd, controls the second switch tube 22 to enter an on state, and the bus voltage 16 is transmitted to the external load based on the second USB-A interface 23. When the current flowing through the second resistor 21 is less than a preset threshold value, the second control module 24 considers that the external device has been pulled out or has entered a full state, controls the second switch tube 22 to enter an off state, and schedules the bus voltage 16 to other USB interfaces.

[0038] The above method is not friendly to small-current external loads, and the charging current of the small-current external load is smaller than the preset threshold when the small-current external load is not in the full charging state. During the charging process, the first control module 15 or the second control module 24 mistakenly considers that the small-current external load is fully charged based on the current flowing through the first resistor 12 or the second resistor 21, and then cuts off the path of the bus voltage provided to the external load.

[0039] Based on the pain points existing in the above method, some related technologies increase the amplification capability of the amplifier, set the preset threshold to be smaller, and thus are compatible with the charging scene of the small-current external load. However, this method can only continuously approach the control of the small-current external load to enter the full charging state, and cannot fundamentally control the small-current external load to enter the full charging state. Moreover, the design of the amplifier with multiple amplification capabilities is prone to increase the hardware cost and design difficulty.

[0040] In the embodiment of the present application, when the charging current meets the standby charging condition, the charging mode of the external load provided by the bus voltage is switched to the charging mode of the external load provided by the standby power supply circuit. In this way, not only the large-current external load can be fully charged, but also the small-current external load can be fully charged.

[0041] In the following, the embodiment of the present application provides a charger. Please refer to Figure 3 The charger 300 includes a step-down circuit 400 and a multi-interface USB circuit 500. The step-down circuit 400 and the multi-interface USB circuit 500 are electrically connected.

[0042] The step-down circuit 400 is used to provide a bus voltage. The bus voltage is output by the step-down circuit 400 configured by the designer according to the business demand. For example, the step-down circuit 400 can convert a 36V voltage into a 5V voltage for output. Therefore, the bus voltage is 5V.

[0043] It can be understood that, in some embodiments, the step-down circuit 400 is a circuit with a step-down function formed by various discrete components. In some embodiments, the step-down circuit 400 is a step-down chip.

[0044] Please refer to Figure 4 The multi-interface USB circuit 500 includes a controller 51, a first type of USB interface 52, a second type of USB interface 53, a current sampling circuit 54, a direct current bus 55, a switching unit 56, and a standby power supply circuit 57.

[0045] The controller 51 is the control core of the multi-interface USB circuit 500, and is used to process and analyze various charging business logics. The controller 51 supports multiple USB interface protocols, including a USB-A interface protocol, a USB-B interface protocol, or a USB-C interface protocol.

[0046] The first type of USB interface 52 is electrically connected to the controller 51, and the first type of USB interface 52 is a USB interface supporting CC pin-based detection of device insertion.

[0047] The second type of USB interface 53 is electrically connected to the controller 51, and the second type of USB interface 53 is a USB interface not supporting CC pin-based detection of device insertion.

[0048] In some embodiments, the first type of USB interface 52 is a USB-C interface circuit, and the second type of USB interface 53 is a USB-A interface circuit. In some embodiments, the first type of USB interface 52 is a USB-C interface circuit, and the second type of USB interface 53 is a USB-B interface circuit.

[0049] The current sampling circuit 54 is electrically connected to the second type of USB interface 53 and the controller 51, respectively. In some embodiments, the current sampling circuit 54 is a sampling resistor. In some embodiments, the current sampling circuit 54 is a Hall sensor, etc.

[0050] The DC bus 55 is used to transmit the bus voltage 57.

[0051] The switch unit 56 is electrically connected to the controller 51, the first type of USB interface 52, the second type of USB interface 53, and the DC bus 55, respectively. The switch unit 56 forms a current loop with the second type of USB interface 53 and the current sampling circuit 54 in response to the external load 58 being inserted into the second type of USB interface 53, and under the action of the bus voltage 57, current flows in the current loop, wherein the current can reflect the charging condition of the external load 58. When the current becomes smaller and smaller, it means that the external load is close to the full state.

[0052] The controller 51 controls the switch unit 56 to disconnect the path through which the bus voltage 57 is applied to the second type of USB interface 53 and outputs a standby power supply signal in response to the charging current flowing through the current loop meeting the standby charging condition.

[0053] In some embodiments, when the charging current flowing through the current loop has a gradually decreasing trend, and the charging current flowing through the current loop is less than a preset current threshold, the controller 51 determines that the charging current flowing through the current loop meets the standby charging condition.

[0054] In some other embodiments, when the charging current flowing through the current loop has a gradually decreasing trend, the controller 51 determines that the charging current flowing through the current loop meets the standby charging condition.

[0055] In some other embodiments, when the charging current flowing through the current loop is less than a preset current threshold, the controller 51 determines that the charging current flowing through the current loop meets the standby charging condition.

[0056] When the controller 51 controls the switch unit 56 to disconnect the path through which the bus voltage 57 is applied to the second-type USB interface 53, the bus voltage 57 cannot be applied to the second-type USB interface 53, and thus the external load 58 cannot obtain the charging power corresponding to the bus voltage 57. Further, the controller 51 can dispatch the charging power corresponding to the bus voltage 57 to the load connected to the first-type USB interface 52.

[0057] The standby power supply signal is used to enable the standby power supply circuit 57 to enter an active state.

[0058] The standby power supply circuit 57 is electrically connected to the second-type USB interface 53 and the controller 51 respectively. The standby power supply circuit 57 is used to provide power to the external load 58 based on the second-type USB interface 53 in response to the standby power supply signal. The standby power supply circuit 57 occupies a small amount of power and can provide a small amount of current to the external load 58 to ensure that the external load 58 can be charged at a low power.

[0059] When the external load 58 is a load that supports high-power charging, the charging current is large. When the charging current of the external load 58 gradually decreases and is lower than a preset current threshold, the controller 51 controls the bus voltage to stop being applied to the external load 58, and controls the standby power supply circuit 57 to provide power to the external load 58 based on the second-type USB interface 53. In this way, such an external load can still receive the power provided by the standby power supply circuit 57 for charging when it is close to a full state, thereby reliably prompting such an external load to enter the full state.

[0060] When the external load 58 is a load that supports low-power charging, the charging current is small. When the charging current of the external load 58 gradually decreases and is lower than a preset current threshold, the controller 51 controls the bus voltage to stop being applied to the external load 58, and controls the standby power supply circuit 57 to provide power to the external load 58 based on the second-type USB interface 53. In this way, such an external load can continuously receive the power provided by the standby power supply circuit 57 for charging, thereby reliably ensuring that such an external load can receive sufficient power to enter the full state.

[0061] In some embodiments, referring to Figure 5 , the switch unit 56 includes a first switch circuit 561 and a second switch circuit 562.

[0062] The first switch circuit 561 is electrically connected to the controller 51 and the first-type USB interface 52 respectively, and is used to apply the bus voltage to the first-type USB interface 52 in a first switch state, and disconnect the path through which the bus voltage is applied to the first-type USB interface 52 in a second switch state.

[0063] The controller 51 controls the first switch circuit 561 to enter the first switch state in response to the first type USB interface 52 being plugged into the charging device, so that the bus voltage can be provided to the charging device through the first type USB interface 52 for charging. The controller 51 controls the first switch circuit 561 to enter the second switch state in response to the first type USB interface 52 being unplugged from the charging device or the first type USB interface 52 being in an idle state.

[0064] It can be understood that the first switch state and the second switch state depend on the switch design of the first switch circuit 561. In some embodiments, the first switch state is an on state, and the second switch state is an off state. In some embodiments, the first switch state is an off state, and the second switch state is an on state.

[0065] In some embodiments, referring to Figure 6 , the first type USB interface 52 includes a first power pin 521, and the first switch circuit 561 includes a first NMOS tube Q1. The drain of the first NMOS tube Q1 is applied with the bus voltage, the source is electrically connected with the first power pin 521, and the gate is electrically connected with the controller 51.

[0066] The controller 51 sends a high level to the gate of the first NMOS tube Q1 to control the first NMOS tube Q1 to enter the on state (i.e., the first switch state) in response to the first type USB interface 52 being plugged into the charging device. The controller 51 sends a low level to the gate of the first NMOS tube Q1 to control the first NMOS tube Q1 to enter the off state (i.e., the second switch state) in response to the first type USB interface 52 being unplugged from the charging device or the first type USB interface 52 being in an idle state.

[0067] It can be understood that, in addition to the first NMOS tube Q1 being configured to the first switch circuit 561, other types of electronic switch tubes can also be configured to the first switch circuit 561, which will not be described here.

[0068] The second switch circuit 562 is electrically connected with the controller 51 and the second type USB interface 53 respectively, and is configured to apply the bus voltage to the second type USB interface 53 in the third switch state and disconnect the bus voltage from the second type USB interface in the fourth switch state.

[0069] The controller 51 controls the second switch circuit 562 to enter the third switch state in response to the second type USB interface 53 being plugged into the external load, so that the bus voltage can be provided to the external load through the second type USB interface 53 for charging. The controller 51 controls the second switch circuit 562 to enter the fourth switch state in response to the second type USB interface 53 being unplugged from the external load or the second type USB interface 53 being in an idle state.

[0070] Similarly, the third switch state and the fourth switch state depend on the switch design of the second switch circuit 562. In some embodiments, the third switch state is the on state and the fourth switch state is the off state. In some embodiments, the third switch state is the off state and the fourth switch state is the on state.

[0071] In some embodiments, please refer to Figure 6 , the second type of USB interface 53 includes a second power pin 531, and the second switch circuit 562 includes a second NMOS tube Q2. The drain of the second NMOS tube Q2 is applied with the bus voltage, the source is electrically connected with the second power pin 531, and the gate is electrically connected with the controller 51.

[0072] The controller 51 sends a high level to the gate of the second NMOS tube Q2 in response to the insertion of the second type of USB interface 53 into an external load, so as to control the second NMOS tube Q2 to enter the on state (i.e. the third switch state). The controller 51 sends a low level to the gate of the second NMOS tube Q2 in response to the disconnection of the second type of USB interface 53 from the charging device, so as to control the second NMOS tube Q2 to enter the off state (i.e. the fourth switch state).

[0073] It can be understood that when the second type of USB interface 53 is in the idle state, the controller 51 controls the second NMOS tube Q2 to enter the on state. When the external load is inserted into the second type of USB interface 53, the bus voltage can be directly provided to the external load for charging through the second type of USB interface 53.

[0074] It can also be understood that in addition to the second NMOS tube Q2 being selected to configure the second switch circuit 562, other types of electronic switch tubes can also be selected to configure the second switch circuit 562, which will not be described here.

[0075] In some embodiments, please refer to Figure 6 The current sampling circuit 54 includes a sampling resistor R1. One end of the sampling resistor R1 is electrically connected with the second power pin 531, and the other end of the sampling resistor R1 is grounded. The controller 51 is electrically connected with both ends of the sampling resistor R1.

[0076] Please refer to Figure 7 The standby power supply circuit 57 is a low-power power supply chip. The low-power power supply chip includes a power input end Vin, an enable end EN, and a power output end VBUS_A. The power input end Vin is applied with the bus voltage. The enable end EN is electrically connected with the controller 51. The power output end VBUS_A is electrically connected with the second power pin 531.

[0077] The controller 51 sends a standby power supply signal to the standby power supply circuit 57 based on the enable end EN, and the standby power supply circuit 57 enters a working state in response to the standby power supply signal, converts the bus voltage input from the power input end Vin into a corresponding voltage, and transmits the voltage to the external load through the power output end VBUS_A. As described above, the embodiment of the application switches from the charging mode of the external load by the bus voltage to the charging mode of the external load by the standby power supply circuit 57 when the current meets the standby charging condition, so that not only the external load with large current can be fully charged, but also the external load with small current can be fully charged.

[0078] Referring to Figure 8 , the multi-interface USB circuit 500 further includes a discharge circuit 59 electrically connected with the DC bus 55 and the controller 51 respectively, for discharging interference signals flowing through the DC bus 55 in response to the control of the controller 51. When the bus voltage is suddenly disconnected or the USB interface is in a non-working state, the discharge circuit 59 can discharge the residual charge of the multi-interface USB circuit 500, avoid the occurrence of dangerous situations such as short circuit, and prevent the damage of the equipment or the harm to the human body caused by the accumulation of charge. In addition, the discharge circuit 59 can also discharge the inrush current or the peak voltage and the like.

[0079] Referring to Figure 9 , the discharge circuit 59 includes a current-limiting voltage-dividing circuit 591 and a discharge switch 592. The current-limiting voltage-dividing circuit 591 is electrically connected with the DC bus 55. The discharge switch 592 is electrically connected with the current-limiting voltage-dividing circuit 591 and the controller 51 respectively, for discharging interference signals flowing through the DC bus 55 in response to the control of the controller 51.

[0080] Please refer to Figure 6 , the current-limiting voltage-dividing circuit 591 includes a resistor R2 and a resistor R3, and the discharge switch 592 includes a switch tube Q3. One end of the resistor R2 is electrically connected with the DC bus 55, and the other end of the resistor R2 is electrically connected with the drain of the switch tube Q3. The gate of the switch tube Q3 is electrically connected with the controller 51 and one end of the resistor R3 respectively, and the other end of the resistor R3 and the source of the switch tube Q3 are grounded. The controller 51 sends a high level to the gate of the switch tube Q3, and the switch tube Q3 enters a conducting state, and the interference signal is discharged to the ground through the switch tube Q3.

[0081] Finally, it should be noted that: the above examples are used to illustrate the technical solutions of the present application, rather than limiting them; under the idea of the present application, the technical features in the above examples or different examples can also be combined, the steps can be implemented in any order, and there are many other changes of different aspects of the present application as described above, which are not provided in detail for simplicity; although the present application has been described in detail with reference to the foregoing examples, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing examples, or make equivalent replacement for part of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A multi-interface USB circuit, characterized by, The application relates to a multi-interface USB circuit, comprising: a controller; a first type of USB interface, which is electrically connected to the controller, and is a USB interface supporting CC pin-based detection of device insertion; a second type of USB interface, which is electrically connected to the controller, and is a USB interface not supporting CC pin-based detection of device insertion; a current sampling circuit, which is electrically connected to the second type of USB interface and the controller respectively; a DC bus for transmitting a bus voltage; a switching unit, which is electrically connected to the controller, the first type of USB interface, the second type of USB interface and the DC bus respectively, and which forms a current loop with the second type of USB interface and the current sampling circuit in response to external load insertion into the second type of USB interface; the controller controls the switching unit to disconnect the bus voltage from the second type of USB interface and outputs a standby power supply signal in response to charging current flowing through the current loop meeting standby charging conditions; a standby power supply circuit, which is electrically connected to the second type of USB interface and the controller respectively, and which provides power supply to the external load based on the second type of USB interface in response to the standby power supply signal.

2. The multi-interface USB circuit of claim 1, wherein, The switching unit comprises: a first switching circuit, which is electrically connected to the controller and the first type of USB interface respectively, and which applies the bus voltage to the first type of USB interface in a first switching state and disconnects the bus voltage from the first type of USB interface in a second switching state; a second switching circuit, which is electrically connected to the controller and the second type of USB interface respectively, and which applies the bus voltage to the second type of USB interface in a third switching state and disconnects the bus voltage from the second type of USB interface in a fourth switching state.

3. The multi-interface USB circuit according to claim 2, wherein: the first type of USB interface comprises a first power supply pin; the first switching circuit comprises a first NMOS tube, the drain of the first NMOS tube is applied with the bus voltage, the source is electrically connected to the first power supply pin, and the gate is electrically connected to the controller.

4. The multi-interface USB circuit according to claim 2, wherein: the second type of USB interface comprises a second power supply pin; the second switching circuit comprises a second NMOS tube, the drain of the second NMOS tube is applied with the bus voltage, the source is electrically connected to the second power supply pin, and the gate is electrically connected to the controller.

5. The multi-interface USB circuit of claim 4, wherein, The current sampling circuit comprises a sampling resistor, one end of the sampling resistor is electrically connected to the second power supply pin, the other end of the sampling resistor is grounded, and the controller is electrically connected to both ends of the sampling resistor.

6. The multi-interface USB circuit of claim 4, wherein, The standby power supply circuit is a low-power power supply chip, the low-power power supply chip comprises a power supply input end, an enable end and a power supply output end, the power supply input end is applied with the bus voltage, the enable end is electrically connected to the controller, and the power supply output end is electrically connected to the second power supply pin.

7. The multi-interface USB circuit of claim 1, wherein, The first type of USB interface is a USB-C interface circuit, and the second type of USB interface is a USB-A interface circuit.

8. The multi-interface USB circuit of any of claims 1 to 7, wherein, Further comprising a bleed circuit, which is electrically connected with the DC bus and the controller respectively, and is used for bleeding the interference signal flowing through the DC bus in response to the control of the controller.

9. The multi-interface USB circuit of claim 8, wherein, The bleed circuit comprises: a current-limiting voltage-dividing circuit, which is electrically connected with the DC bus; a bleed switch, which is electrically connected with the current-limiting voltage-dividing circuit and the controller respectively, and is used for bleeding the interference signal flowing through the DC bus in response to the control of the controller.

10. A charger characterized by comprising: comprises: a step-down circuit, which is used for providing a bus voltage; The multi-interface USB circuit of any one of claims 1 to 9, wherein a DC bus of the multi-interface USB circuit is electrically connected with the step-down circuit.

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