A USB output circuit and device for controlling multiple USB outputs through a single resistor

Abstract

The present invention relates to the field of charging technology, and more particularly to a USB output circuit and device for controlling multi-port USB outputs via a single resistor. The circuit comprises a single first resistor and multiple USB output units. The multiple USB output units are connected via the first resistor, and the output power of the USB ports themselves is intelligently adjusted via the first resistor. This allows the entire circuit to appropriately control the maximum output power of each USB port while reducing the size and cost of a front-end power supply module. This addresses the problem in the prior art of lacking a control strategy capable of cost-effectively implementing intelligent power distribution for a small-sized, multi-port USB output circuit. Furthermore, the circuit provided by embodiments of the present invention is simple, highly reliable, and low-cost, enabling more flexible power distribution of the USB ports.

Description

Technical Field

[0001] The present invention relates to the field of charging technology, and in particular to a USB output circuit and a device for controlling multi-port USB outputs through a single resistor. Background Art

[0002] With the development of electronic products, the market demand for small-sized and multi-port output products is increasing. Currently, most multi-channel USB outputs are expensive and bulky due to factors such as molds. In addition, the output power is also limited, and the output power cannot be flexibly allocated.

[0003] Prior art 1: Figure 1 For an existing two-way USB output circuit, in this circuit diagram, the power conversion module and fast charging output module in the two USB output circuits are independent of each other. The front-end power supply module needs to meet the sum of the maximum power outputs of the first and second USB output circuits. Therefore, the front-end power supply module is large in size and relatively expensive, and cannot achieve intelligent distribution of the output power of the two USB ports. The front-end power supply module needs to meet the maximum power output of both outputs.

[0004] Prior art 2: Figure 2 Compared with the existing two-way USB output circuit Figure 1 The circuit diagram shows a two-way USB output circuit with an additional single USB output detection and control module. This module can detect the output status of each USB port, including whether a device is connected, output voltage, and other operating parameters. It then appropriately controls the maximum output power of the two USB output circuits based on the status of each port. However, the control logic of the USB output detection and control module in this circuit is complex and generally requires a microcontroller to implement, significantly increasing the cost and development cycle of the solution. Summary of the Invention

[0005] The present invention provides a multi-port output circuit controlled by resistors, which solves the technical problem that the prior art lacks a control strategy that can realize intelligent power distribution of a small-sized multi-port USB output circuit at low cost.

[0006] To solve the above technical problems, the present invention provides a USB output circuit for controlling multi-port USB outputs through a single resistor, which is connected between a front-end power supply module and multiple USB ports, and includes a multi-channel USB output unit connected between the front-end power supply module and the multiple USB ports, and also includes a single first resistor connected to each of the USB output units;

[0007] The front-end power supply module is used to supply power to the USB output unit;

[0008] Each of the USB output units is used to detect and control the output state of the USB port connected thereto according to the first resistor;

[0009] The first resistor is used to indicate the output status of the plurality of USB ports.

[0010] This technical solution connects multiple USB output units through a single first resistor, and each USB output unit detects the output status of the connected USB port. In addition, each USB output unit can control the voltage of the first resistor so that the first resistor indicates the output status of the USB port connected to it. At the same time, each USB output unit can also detect the output status of other USB ports through the voltage of the first resistor, thereby controlling the output of the USB port connected to it, such as turning off the fast charging output, reducing the fast charging power, etc. This technical solution uses a single first resistor to achieve intelligent and low-cost regulation of the power output of the USB port, thereby achieving the USB output circuit meeting the maximum power of multiple outputs while reducing the volume of the front-end power supply module and reducing the cost of the front-end power supply module.

[0011] In a further embodiment, each of the USB output units includes a power conversion module, a fast charge output module, and a status indication, detection, and control module connected in pairs, the power conversion module is also connected to the front-end power supply module, the fast charge output module and the status indication, detection, and control module are also connected to the corresponding USB port, and the status indication, detection, and control module includes a USB status detection module, a current source control module, a detection and comparison module, and a USB output control module connected between the USB port and the power conversion module and connected in sequence;

[0012] The USB status detection module is used to detect the output status of the USB port and the external device, and output a first logic signal;

[0013] The current source control module is used to adjust the voltage of the first resistor according to the first logic signal;

[0014] The detection and comparison module is used to detect and compare the voltage of the first resistor connected to the current source control module, and output a voltage comparison signal to the USB output control module;

[0015] The USB output control module is used to generate a control strategy.

[0016] Each of the USB output units in this technical solution includes the status indication, detection, and control module. Therefore, the control logic of the status indication, detection, and control module is relatively simple and easy to implement. Therefore, the status indication, detection, and control module can also significantly reduce the cost of the USB output circuit and shorten the development cycle, without the need for complex microcontroller control.

[0017] In a further embodiment, the USB status detection module includes a second resistor, a third resistor, and a fourth resistor connected in sequence, and a first sampler connected across the second resistor, and further includes a first comparator, a second comparator, and a first NOR gate;

[0018] The other end of the second resistor is connected to the power supply terminal of the USB port; the other end of the fourth resistor is grounded; the non-inverting input end of the first sampler is connected to the common end of the second resistor and the power supply terminal of the USB port, and the inverting input end of the first sampler is connected to the common end of the second resistor and the third resistor;

[0019] The non-inverting input terminal of the first comparator is connected to the output terminal of the first sampler, the inverting input terminal of the first comparator is connected to the first voltage signal, and the output terminal of the first comparator is electrically connected to the first input terminal of the first NOR gate;

[0020] The non-inverting input terminal of the second comparator is connected to the common terminal of the third resistor and the fourth resistor, the inverting input terminal of the second comparator is connected to the second voltage signal, and the output terminal of the second comparator is electrically connected to the second input terminal of the first NOR gate;

[0021] The third input terminal of the first NOR gate is electrically connected to the first output terminal of the fast charge output module;

[0022] The fourth input terminal of the first NOR gate is electrically connected to the second output terminal of the fast charging output module;

[0023] The first comparator and the second comparator input the first state signal and the second state signal outputted from the output terminals into the first NOR gate.

[0024] This technical solution implements current sampling of the power supply end of the USB port through the first sampler and the second resistor; implements current detection and voltage detection of the USB port connected thereto through the first comparator and the second comparator, and correspondingly outputs the first state signal and the second state signal to the first NOR gate, and uses the two signals to indicate whether a device is inserted; the first NOR gate is also used to receive the differential state signal and the third state signal detected by the fast charging output module, thereby enabling the current source control module to adjust the voltage of the first resistor, and provide data information for the control strategy generated by the USB output control module, thereby achieving flexible allocation of the output power of the USB port.

[0025] In a further embodiment, the current source control module includes a current source, a first MOS transistor, and an inverter, and the inverter includes a second MOS transistor and a third MOS transistor connected in series;

[0026] The drain of the first MOS transistor is connected to the negative electrode of the current source, the source of the first MOS transistor is connected to one end of the first resistor, and the gate of the first MOS transistor is connected to the common end of the drain of the second MOS transistor and the drain of the third MOS transistor; the other end of the first resistor is grounded;

[0027] The source of the second MOS transistor is grounded, the drain of the second MOS transistor is connected to the drain of the third MOS transistor, and the gate of the second MOS transistor is connected to the output end of the first NOR gate;

[0028] The source of the third MOS transistor is connected to the positive electrode of the current source, the drain of the third MOS transistor is connected to the drain of the second MOS transistor, and the gate of the third MOS transistor is connected to the output end of the first NOR gate.

[0029] Specifically, the current source control module controls the on and off of the first MOS transistor and the current source according to the first logic signal outputted from the output terminal of the first NOR gate.

[0030] In this technical solution, the current source control module of each path adjusts the voltage of the first resistor connected to the first MOS transistor by controlling the on / off of the first MOS transistor and the current source, thereby achieving the effect of indicating the output status of multiple USB ports through the first resistor, and also realizing intelligent adjustment of the output power of the USB port itself through the first resistor.

[0031] In a further embodiment, the detection and comparison module includes a third comparator and a fourth comparator, the non-inverting input terminal of the third comparator is connected to the common terminal of the first resistor and the source of the first MOS transistor, and the inverting input terminal of the third comparator is connected to the third voltage signal;

[0032] The non-inverting input terminal of the fourth comparator is connected to the common terminal of the first resistor and the source of the first MOS transistor, and the inverting input terminal of the fourth comparator is connected to the fourth voltage signal.

[0033] The detection and comparison module in this technical solution provides the USB output control module with the current output status of the other USB ports by comparing the voltage of the first resistor, providing a data basis for the USB output control module to generate a control strategy.

[0034] In a further embodiment, the USB output control module includes a second NOR gate and an output control state machine, wherein the first input of the second NOR gate is electrically connected to the output of the first comparator, the second input of the second NOR gate is electrically connected to the output of the second comparator, the third input of the second NOR gate is electrically connected to the second output of the fast charge output module, and the output of the second NOR gate is electrically connected to the input of the output control state machine; the input of the output control state machine is also connected to the output of the third comparator and the output of the fourth comparator;

[0035] The output end of the output control state machine is connected to the input end of the power conversion module.

[0036] Specifically, the output end of the second NOR gate inputs the output second logic signal into the output control state machine; the output ends of the third comparator and the fourth comparator respectively input the output first voltage comparison signal and the output second voltage comparison signal into the output control state machine;

[0037] The output control state machine generates the control strategy according to the received second logic signal and the first voltage comparison signal and the second voltage comparison signal.

[0038] The output control state machine in this technical solution generates an output control strategy for the USB port connected thereto according to the input signal, thereby adjusting the maximum power output of the USB port connected thereto; in a multi-port USB output solution, the output control state machine can achieve more flexible power distribution of the USB ports.

[0039] In a further embodiment, the fast charge output module is used to detect the differential signal of the USB port, and output a differential state signal and a third state signal to the USB state detection module and the USB output control module respectively according to the detected differential signal;

[0040] Also used to control and adjust the fast charging protocol of the USB port according to the control strategy;

[0041] The power conversion module is used to control the output power of the USB port according to the fast charging protocol and the received control strategy.

[0042] In this technical solution, the fast charging output module switches each fast charging protocol according to the control strategy, or adjusts the output specifications of each fast charging protocol; this technical solution realizes the adjustment of the maximum output power supported by the USB port connected to it through the power conversion module, so that the total output power is controlled at an appropriate level, and also solves the problems of product heat dissipation and total output power exceeding the power supply capacity of the front-end power supply module in the prior art.

[0043] A device includes the above-mentioned USB output circuit for controlling multi-port USB outputs through a single resistor. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 It is a structural diagram of a USB output circuit of the prior art 1 provided by the background technology of the present invention;

[0045] Figure 2 It is a structural diagram of the USB output circuit of the prior art 2 provided by the background technology of the present invention;

[0046] Figure 3 This is a schematic structural diagram of a USB output circuit for controlling multiple USB outputs through a single resistor, provided by an embodiment of the present invention;

[0047] Figure 4 This is a circuit diagram of a status indication, detection and control module provided by an embodiment of the present invention;

[0048] Figure 5 1 is a schematic diagram of a power conversion module circuit provided by an embodiment of the present invention;

[0049] Figure 6 4 is a state diagram of an output control state machine provided by an embodiment of the present invention.

[0050] Graphic annotation:

[0051] Front-end power supply module 1; power conversion module 2; fast charging output module 3;

[0052] Status indication, detection and control module 4 (USB status detection module 41, current source control module 42, detection and comparison module 43, USB output control module 44);

[0053] Current source 421; inverter 422;

[0054] Output state control machine 441;

[0055] Output power control module 5; enabling module 6; power MOS and driving module 7. DETAILED DESCRIPTION

[0056] The following describes the embodiments of the present invention in detail with reference to the accompanying drawings. The embodiments are provided for illustrative purposes only and are not to be construed as limiting the present invention. The accompanying drawings are provided for reference and illustration only and do not constitute a limitation on the scope of protection of the present invention. Many changes may be made to the present invention without departing from the spirit and scope of the present invention.

[0057] In view of the problem that the prior art lacks a control strategy that can realize the intelligent power distribution of a small-sized and multi-port USB output circuit at low cost, the embodiment of the present invention provides a USB output circuit that controls the output of multiple USB ports through a single resistor, which is connected between a front-end power supply module 1 and multiple USB ports (USB port 1-USB port n). Figure 3 The structural schematic diagram shown includes a multi-channel USB output unit (USB output unit 1-USB output unit n) connected between the front-end power supply module 1 and the multiple USB ports (USB port 1-USB port n), and also includes a single first resistor R1 connected to each of the USB output units (USB output unit 1-USB output unit n);

[0058] The front-end power supply module 1 is used to supply power to each of the USB output units (USB output unit 1 to USB output unit n);

[0059] Each of the USB output units (USB output unit 1 to USB output unit n) is used to detect and control the output state of the USB port (USB port 1 to USB port n) connected thereto according to the first resistor R1;

[0060] The first resistor R1 is used to indicate the output status of the plurality of USB ports (USB port 1 to USB port n).

[0061] Each of the USB output units (USB output unit 1-USB output unit n) includes a power conversion module 2, a fast charge output module 3, and a status indication, detection, and control module 4 connected in pairs. The power conversion module 2 is also connected to the front-end power supply module 1, and the fast charge output module 3 and the status indication, detection, and control module 4 are also connected to the corresponding USB port.

[0062] For the convenience of explanation, the embodiment of the present invention is mainly described by taking two USB output circuits as an example. Figure 4 As shown, the status indication, detection and control module 4 includes a USB status detection module 41, a current source control module 42, a detection and comparison module 43 and a USB output control module 44 connected between the USB ports (USB port 1 to USB port n) and the power conversion module 2 and connected in sequence;

[0063] The USB status detection module 41 includes a second resistor R2, a third resistor R3, and a fourth resistor R4 connected in sequence, and a first sampler OP1 (N) connected across the second resistor R2, a first comparator COMP1, a second comparator COMP2, and a first NOR gate N1;

[0064] The other end of the second resistor R2 is connected to the power supply terminal VBUS of the USB port (USB port 1 to USB port n); the other end of the fourth resistor R4 is grounded GND;

[0065] A non-inverting input terminal of the first sampler OP1(N) is connected to a common terminal of the second resistor R2 and the power supply terminal VBUS of the USB port (USB port 1 to USB port n), and an inverting input terminal of the first sampler OP1(N) is connected to a common terminal of the second resistor R2 and the third resistor R3;

[0066] The non-inverting input terminal of the first comparator COMP1 is connected to the output terminal of the first sampler OP1(N), the inverting input terminal of the first comparator COMP1 is connected to the first voltage signal V1, and the output terminal of the first comparator COMP1 is electrically connected to the first input terminal of the first NOR gate N1;

[0067] A non-inverting input terminal of the second comparator COMP2 is connected to a common terminal of the third resistor R3 and the fourth resistor R4, an inverting input terminal of the second comparator COMP2 is connected to the second voltage signal V2, and an output terminal of the second comparator COMP2 is electrically connected to the second input terminal of the first NOR gate N1;

[0068] The third input terminal of the first NOR gate N1 is electrically connected to the first output terminal of the fast charge output module 3;

[0069] The fourth input terminal of the first NOR gate N1 is electrically connected to the second output terminal of the fast charging output module 3;

[0070] The first comparator COMP1 and the second comparator COMP2 input the first state signal USB_STATE1 and the second state signal USB_STATE2 outputted from the output terminals into the first NOR gate N1 .

[0071] The USB state detection module 41 samples and compares the current on the power supply terminal VBUS of the USB port (USB port 1 to USB port n) through the second resistor R2, the first sampler OP1(N), and the first comparator COMP1, and the first comparator COMP1 outputs the first state signal USB_STATE1;

[0072] In an embodiment of the present invention, the first state signal USB_STATE1 is used to indicate the current change of the VBUS path of the power supply terminal. If the current is greater than the current setting value Iset, the output value of the first comparator COMP1 changes from 0 to 1, indicating that a device is plugged in; if the current is less than the current setting value Iset, the output value of the first comparator COMP1 is 0, indicating that no device is plugged in.

[0073] The derivation formula of the current setting value is as follows:

[0074] Iset=V1 / (N*R1) (1)

[0075] Wherein, N is determined by the amplification factor of the first sampler OP1 (N) for collecting the voltage of the second resistor R2.

[0076] The USB state detection module 41 detects and compares the voltage of the power supply terminal VBUS of the USB port (USB port 1 to USB port n) through the third resistor R3, the fourth resistor R4, and the second comparator COMP2, and the second comparator COMP2 outputs the second state signal USB_STATE2;

[0077] In an embodiment of the present invention, the second state signal USB_STATE2 is used to indicate the voltage change of the VBUS path of the power supply terminal. If the voltage is greater than the voltage setting value Vset, the output value of the second comparator COMP2 changes from 0 to 1, indicating that a device is plugged in; if the voltage is less than the voltage setting value Vset, the output value of the second comparator COMP2 changes from 0 to 1, indicating that no device is plugged in.

[0078] The derivation formula of the voltage setting value is as follows:

[0079] Vset=(1+R3 / R4)*V2 (2)

[0080] The fast charge output module 3 outputs the differential state signal QCOK and the third state signal USB_STATE3 of the USB port (USB port 1-USB port n) according to the differential signal DP / DM / CC of the data end of the USB port (USB port 1-USB port n);

[0081] In an embodiment of the present invention, when the external device connected to the USB port (USB port 1 to USB port n) is in fast charging state, the differential state signal QCOK=1; in other cases, the differential state signal QCOK=0;

[0082] In an embodiment of the present invention, the third state signal USB_STATE3 is used to indicate a differential change of the data end of the USB port (USB port 1 to USB port n). When the state of the differential signal DP / DM / CC is not the original state, the third state signal USB_STATE3 is 1, indicating that a device is inserted; when the state of the differential signal DP / DM / CC is the original state, the third state signal USB_STATE3 is 0, indicating that no device is inserted.

[0083] The first NOR gate N1 receives the first state signal USB_STATE1, the second state signal USB_STATE2, the third state signal USB_STATE3 and the differential state signal QCOK, and outputs a first logic signal after performing a NOR logic operation;

[0084] In an embodiment of the present invention, the differential state signal QCOK input to the first NOR gate N1, one of the first state signal USB_STATE1, the second state signal USB_STATE2, and the third state signal USB_STATE3 is 1, and the first logic signal output by the first NOR gate N1 is 0.

[0085] It should be noted that the current sampling and comparison on the power supply end VBUS path can also be achieved through current sampling in the power MOS and the driving module 7.

[0086] The current source control module 42 includes a current source 421, a first MOS transistor NM1, and an inverter 422. The inverter 422 includes the second MOS transistor NM2 and the third MOS transistor PM1 connected in series.

[0087] The drain D of the first MOS transistor NM1 is connected to the negative electrode of the current source 421, the source S of the first MOS transistor NM1 is connected to one end of the first resistor R1, and the gate G of the first MOS transistor NM1 is connected to the common end of the drain D of the second MOS transistor NM2 and the drain D of the third MOS transistor PM1; the other end of the first resistor R1 is grounded GND.

[0088] The source S of the second MOS transistor NM2 is grounded GND, the drain D of the second MOS transistor NM2 is connected to the drain D of the third MOS transistor PM1, and the gate G of the second MOS transistor NM2 is connected to the output end of the first NOR gate N1;

[0089] The source S of the third MOS transistor PM1 is connected to the positive electrode of the current source 421 , the drain D of the third MOS transistor PM1 is connected to the drain D of the second MOS transistor NM2 , and the gate G of the third MOS transistor PM1 is connected to the output end of the first NOR gate N1 .

[0090] The first MOS transistor NM1 is an n-type substrate MOS transistor; the second MOS transistor NM2 is an N-channel enhancement-mode MOS transistor; and the third MOS transistor PM1 is a P-channel enhancement-mode MOS transistor.

[0091] In the embodiment of the present invention, the current source control module 42 receives the first logic signal outputted from the output terminal of the first NOR gate N1 .

[0092] If the first logic signal is 1, after passing through the inverter 422 of the current source control module 42, the output is 0, and the first MOS transistor NM1 in the path between the current source 421 and the resistor R1 will not be turned on; if the first logic signal is 0, after being enhanced by the inverter 422 of the current source control module 42, the output is 1, thereby controlling the current source 421 and the first MOS transistor NM1 in the path between the resistor R1 to be turned on. After turning on, the voltage on the resistor R1 becomes I1*R1.

[0093] It should be noted that, when only one of the USB ports (USB port 1-USB port n) is connected, the voltage across the first resistor R1 will become I1*R1; when two of the USB ports (USB port 1-USB port n) are connected, the voltage across the first resistor R1 will become 2*I1*R1; thus, when N of the USB ports (USB port 1-USB port n) are connected, the voltage across the first resistor R1 will become N*I1*R1.

[0094] In addition, in an actual solution, the differential state signal QCOK, one or more of the first state signal USB_STATE1, the second state signal USB_STATE2, and the third state signal USB_STATE3 may be used to control the on / off of the current source 421 and the first MOS transistor NM1.

[0095] The detection and comparison module 43 includes a third comparator COMP3 and a fourth comparator COMP4, wherein the non-inverting input terminal of the third comparator COMP3 is connected to the common terminal of the first resistor R1 and the source of the first MOS transistor NM1, and the inverting input terminal of the third comparator COMP3 is connected to the third voltage signal V3;

[0096] A non-inverting input terminal of the fourth comparator COMP4 is connected to a common terminal of the first resistor R1 and the source of the first MOS transistor NM1 , and an inverting input terminal of the fourth comparator COMP4 is connected to the fourth voltage signal V4 .

[0097] The detection and comparison module 43 is used to detect and compare the voltage of the first resistor R1 connected to the current source control module 42, and output a voltage comparison signal to the USB output control module 44;

[0098] In the embodiment of the present invention, the third comparator COMP3 and the fourth comparator COMP4 are used to detect and compare the voltage of the first resistor R1, thereby outputting a first voltage comparison signal VR1 and a second voltage comparison signal VR2 to the USB output control module 44.

[0099] Among them, the size relationship set is V3 <I1*R1<V4<2*I1*R1。

[0100] Similarly, corresponding Figure 3 In the embodiment, if N USB ports (USB port 1 to USB port n) are connected, the number of comparators in the detection and comparison module 43 is increased to N;

[0101] At this time, the set size relationship is: (N-1)*I1*R1 <V(N+2)<N*I1*R1。

[0102] The USB output control module 44 includes a second NOR gate N2 and an output control state machine 441. The first input end of the second NOR gate N2 is electrically connected to the output end of the first comparator COMP1, the second input end of the second NOR gate N2 is electrically connected to the output end of the second comparator COMP2, the third input end of the second NOR gate N2 is electrically connected to the second output end of the fast charge output module 3, and the output end of the second NOR gate N2 is electrically connected to the input end of the output control state machine 441. The input end of the output control state machine 441 is also connected to the output ends of the third comparator COMP3 and the fourth comparator COMP4.

[0103] The output end of the output control state machine 441 is connected to the input end of the power conversion module 2 .

[0104] The second NOR gate N2 is used to receive the first state signal USB_STATE1, the second state signal USB_STATE2, and the third state signal USB_STATE3, and output a second logic signal to the output control state machine 441 after performing a NOR logic operation; if the second logic signal is 0, it indicates that no device is plugged in; if the second logic signal is 1, it indicates that a device is plugged in;

[0105] In this embodiment, the output control state machine 441 receives the second logic signal and determines whether a device is plugged into the USB port (USB port 1 to USB port n) connected thereto through the second logic signal;

[0106] The output control state machine 441 further determines the output states of the other USB ports (USB port 1 to USB port n) according to the first voltage comparison signal VR1 and the second voltage comparison signal VR2 received from the output terminals of the third comparator COMP3 and the fourth comparator COMP4;

[0107] The output control state machine 441 generates the control strategy based on the device insertion status of the USB port (USB port 1-USB port n) connected to it and the output status of other USB ports (USB port 1-USB port n), determines the corresponding gear of its own output power, and thus realizes more flexible power distribution of the USB ports (USB port 1-USB port n).

[0108] It should be noted that, in actual solutions, one or more of the first state signal USB_STATE1, the second state signal USB_STATE2, and the third state signal USB_STATE3 may be used to indicate whether a device is inserted into the USB port (USB port 1-USB port n).

[0109] The fast charging output module 3 controls and adjusts the fast charging protocol of the USB port (USB port 1-USB port n) according to the control strategy;

[0110] The power conversion module 2 adjusts the maximum fast charging power output according to the fast charging protocol and the control strategy.

[0111] Figure 5 This is a circuit diagram of a power conversion module proposed in an embodiment of the present invention. The power conversion module 2 includes an output power control module 5 and an enabling module 6 connected to the USB output control module 44, and also includes a power MOS and a driving module 7 connected to the output power control module 5 and the enabling module 6;

[0112] When the fast charging protocol needs to be changed, first, the fast charging output module 3 switches each fast charging protocol according to the control strategy, or modifies the specifications of each fast charging protocol;

[0113] The specifications of the fast charging protocol include key parameters such as maximum voltage, maximum power, and PD broadcast packet;

[0114] Then, the output power control module 5 and the enabling module 6 turn off the VBUS output of the power supply terminal according to the control strategy. After adjusting the fast charging protocol of the fast charging output module 3, the VBUS output of the power supply terminal is turned on and the maximum output power is limited according to the fast charging protocol and the control strategy.

[0115] In this embodiment, the output power control module 5 limits the output current of the power conversion module 2 by controlling the first reference voltage Vref1, and limits the output voltage of the power conversion module 2 by controlling the second reference voltage Vref2;

[0116] The power MOS and driving module 7 adjusts the output power of the USB port (USB port 1-USB port n) connected thereto according to the output voltage detection signal of the fifth comparator COMP5 in the output power control module 5, the enable signal output by the enable module 6, and the output signal of the PWM, thereby maintaining stable output.

[0117] Figure 6 The output control state machine 441 proposed in the embodiment of the present invention can support high-power fast charging output when a single port is inserted; when two ports are inserted, the maximum supported power can be reduced so that the possible total output power is controlled at an appropriate level, thereby meeting the product heat dissipation requirements and not exceeding the capacity of the front-end power supply module.

[0118] In states S0 and S3, the current source control module 42 turns off the current source 421. In states S1 and S2, the current source 421 is controlled to switch on and off according to product specifications and the status of the USB ports (USB port 1-USB port n) detected by the USB status detection module 41.

[0119] When converting between state S0 and state S3, and between state S1 and state S2, it is generally necessary to first control the power conversion module 2 to turn off the VBUS output of the power supply end, disconnect the differential signal DP / DM / CC connection, and then turn on the VBUS output of the power supply end after the fast charging output protocol of the fast charging output module 3 is adjusted.

[0120] During the transition process among states S0, S1, S2, and S3, the device insertion and device removal transition conditions required between states S0 and S1, and between states S2 and S3 are the results of a logical operation of the first state signal USB_STATE1, the second state signal USB_STATE2, and the third state signal USB_STATE3.

[0121] An embodiment of the present invention provides a USB output circuit for controlling multi-port USB outputs via a single resistor. By connecting multiple USB output units (USB output unit 1-USB output unit n) between a front-end power supply module 1 and multiple USB ports (USB port 1-USB port n), and a single first resistor R1 connected to each of the USB output units (USB output unit 1-USB output unit n), the circuit solves the problem in the prior art of lacking a control strategy capable of cost-effectively achieving intelligent power distribution in a compact, multi-port USB output circuit. The embodiment of the present invention establishes a connection between the multiple USB output units (USB output unit 1-USB output unit n) via the first resistor R1, and also achieves intelligent adjustment of the output power of the USB ports (USB port 1-USB port n) thereof via the first resistor R1. This allows the entire circuit to appropriately control the maximum output power of each USB port (USB port 1-USB port n) while reducing the size of the front-end power supply module 1 and lowering its cost. Furthermore, the circuit provided by the embodiment of the present invention has the advantages of simplicity, high reliability, and compact size, thereby shortening the development cycle and reducing the cost of multi-port USB output devices.

[0122] The above embodiments are preferred implementation modes of the present invention, but the implementation modes of the present invention are not limited to the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications that do not deviate from the spirit and principles of the present invention should be considered as equivalent replacement methods and are included in the scope of protection of the present invention.

Claims

1. A USB output circuit that controls multiple USB outputs through a single resistor, connected between a front-end power supply module and multiple USB ports, characterized by: It includes a multi-channel USB output unit connected between the front-end power supply module and the plurality of USB ports, and also includes a single first resistor connected to each of the USB output units; The front-end power supply module is used to supply power to the USB output unit; Each of the USB output units is used to detect and control the output state of the USB port connected thereto according to the first resistor; The first resistor is used to indicate the output status of the plurality of USB ports; Each of the USB output units includes a power conversion module, a fast charge output module, and a status indication, detection, and control module connected in pairs. The power conversion module is also connected to the front-end power supply module. The fast charge output module and the status indication, detection, and control module are also connected to the corresponding USB port. The status indication, detection, and control module includes a USB status detection module, a current source control module, a detection and comparison module, and a USB output control module connected between the USB port and the power conversion module and connected in sequence. The USB status detection module is used to detect the output status of the USB port and the external device, and output a first logic signal; The current source control module is used to adjust the voltage of the first resistor according to the first logic signal; The detection and comparison module is used to detect and compare the voltage of the first resistor connected to the current source control module, and output a voltage comparison signal to the USB output control module; The USB output control module is used to generate a control strategy; The USB status detection module includes a second resistor, a third resistor, and a fourth resistor connected in sequence, and a first sampler connected at both ends of the second resistor, and also includes a first comparator, a second comparator, and a first NOR gate; The other end of the second resistor is connected to the power supply terminal of the USB port; the other end of the fourth resistor is grounded; the non-inverting input end of the first sampler is connected to the common end of the second resistor and the power supply terminal of the USB port, and the inverting input end of the first sampler is connected to the common end of the second resistor and the third resistor; The non-inverting input terminal of the first comparator is connected to the output terminal of the first sampler, the inverting input terminal of the first comparator is connected to the first voltage signal, and the output terminal of the first comparator is electrically connected to the first input terminal of the first NOR gate; The non-inverting input terminal of the second comparator is connected to the common terminal of the third resistor and the fourth resistor, the inverting input terminal of the second comparator is connected to the second voltage signal, and the output terminal of the second comparator is electrically connected to the second input terminal of the first NOR gate; The third input terminal of the first NOR gate is electrically connected to the first output terminal of the fast charge output module; The fourth input terminal of the first NOR gate is electrically connected to the second output terminal of the fast charging output module; The first comparator and the second comparator input the first state signal and the second state signal outputted from the output terminals into the first NOR gate.

2. The USB output circuit for controlling multiple USB outputs through a single resistor as claimed in claim 1, characterized in that: The current source control module includes a current source, a first MOS transistor and an inverter, and the inverter includes a second MOS transistor and a third MOS transistor connected in series; The drain of the first MOS transistor is connected to the negative electrode of the current source, the source of the first MOS transistor is connected to one end of the first resistor, and the gate of the first MOS transistor is connected to the common end of the drain of the second MOS transistor and the drain of the third MOS transistor; the other end of the first resistor is grounded; The source of the second MOS transistor is grounded, the drain of the second MOS transistor is connected to the drain of the third MOS transistor, and the gate of the second MOS transistor is connected to the output end of the first NOR gate; The source of the third MOS transistor is connected to the positive electrode of the current source, the drain of the third MOS transistor is connected to the drain of the second MOS transistor, and the gate of the third MOS transistor is connected to the output end of the first NOR gate.

3. The USB output circuit for controlling multiple USB outputs through a single resistor as claimed in claim 2, wherein: The current source control module controls the on and off of the first MOS transistor and the current source according to the first logic signal outputted from the output end of the first NOR gate.

4. The USB output circuit for controlling multiple USB outputs through a single resistor as claimed in claim 2, wherein: The detection and comparison module includes a third comparator and a fourth comparator, wherein the non-inverting input terminal of the third comparator is connected to the common terminal of the first resistor and the source of the first MOS transistor, and the inverting input terminal of the third comparator is connected to the third voltage signal; The non-inverting input terminal of the fourth comparator is connected to the common terminal of the first resistor and the source of the first MOS transistor, and the inverting input terminal of the fourth comparator is connected to the fourth voltage signal.

5. The USB output circuit for controlling multiple USB outputs through a single resistor as claimed in claim 4, characterized in that: The USB output control module includes a second NOR gate and an output control state machine, wherein the first input end of the second NOR gate is electrically connected to the output end of the first comparator, the second input end of the second NOR gate is electrically connected to the output end of the second comparator, the third input end of the second NOR gate is electrically connected to the second output end of the fast charge output module, and the output end of the second NOR gate is electrically connected to the input end of the output control state machine; the input end of the output control state machine is also connected to the output ends of the third comparator and the fourth comparator; The output end of the output control state machine is connected to the input end of the power conversion module.

6. The USB output circuit for controlling multiple USB outputs through a single resistor as claimed in claim 5, characterized in that: The output end of the second NOR gate inputs the output second logic signal into the output control state machine; the output ends of the third comparator and the fourth comparator respectively input the output first voltage comparison signal and the output second voltage comparison signal into the output control state machine; The output control state machine generates the control strategy according to the received second logic signal and the first voltage comparison signal and the second voltage comparison signal.

7. The USB output circuit for controlling multiple USB outputs through a single resistor as claimed in claim 6, wherein: The fast charge output module is used to detect the differential signal of the USB port, and output a differential state signal and a third state signal to the USB state detection module and the USB output control module respectively according to the detected differential signal; Also used to control and adjust the fast charging protocol of the USB port according to the control strategy; The power conversion module is used to control the output power of the USB port according to the fast charging protocol and the received control strategy.

8. An electronic device with multiple USB output ports, characterized in that: The USB output circuit comprising the method of any one of claims 1 to 7 for controlling multi-port USB outputs through a single resistor.

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