Front-end circuit of SFP slot and router

Abstract

This application relates to communication equipment, and provides a front-end circuit of an SFP slot and a router, including: a power supply circuit coupled to the SFP slot for providing direct current; a detection circuit connected to the SFP slot for detecting the type of the module plugged into the SFP slot, and controlling the power supply circuit to change the voltage of the output direct current to the SFP slot according to the determined type of the module, so that the module is powered on to establish communication with the SFP slot; the module includes an optical module, an electrical module, and a USB module in the SFP structure. When any module is plugged into the SFP slot, the internal insertion detection system will identify the type of the inserted module and perform adaptive power supply. After normal power supply, through system configuration, the structure of the SFP slot and the SFP module is converted into a corresponding interface, so as to realize the function of the interface.

Description

Technical Field

[0001] This application belongs to the technical field of communication devices, and particularly relates to a front-end circuit of an SFP slot and a router. Background Art

[0002] Currently, existing routers have two drawbacks. One is that the Universal Serial Bus (USB) interface and the Small Form-factor Pluggables (SFP) interface cannot be compatible in terms of structure. Routers with only USB interfaces and routers with only SFP interfaces cannot well cover the needs of all users. For routers equipped with both interfaces simultaneously, not only is the manufacturing cost high, but also having both interfaces takes up a large amount of space, imposing high requirements on the housing design and heat dissipation solutions. Moreover, in circuit design, the USB interface circuit and the SFP interface circuit cannot be reused, and there are significant differences in the conversion circuit and power supply circuit designs for the two interfaces. For routers with both interfaces, the peripheral circuits occupy a large area of the Printed Circuit Board (PCB), which is not conducive to layout design. Summary of the Invention

[0003] The purpose of this application is to provide a front-end circuit of an SFP slot and a router, aiming to solve the problem that traditional SFP interfaces cannot be compatible with multiple interface modules.

[0004] The first aspect of the embodiments of this application provides a front-end circuit of an SFP slot, including:

[0005] A power supply circuit, coupled to the SFP slot, for providing direct current;

[0006] A detection circuit, connected to the SFP slot, for detecting the type of the module plugged into the SFP slot, and controlling the power supply circuit to change the voltage of the output direct current to the SFP slot according to the determined type of the module, so that the module is powered on to establish communication with the SFP slot;

[0007] The module includes an optical module, an electrical module, and a USB module with an SFP structure.

[0008] In one embodiment, when the module plugged into the SFP slot is a first SFP module, the detection circuit controls the power supply circuit to provide a first operating voltage to the SFP slot, so that the first SFP module is powered on to establish communication with the SFP slot;

[0009] When the module plugged into the SFP slot is the second SFP module, the detection circuit controls the power supply circuit to provide a second operating voltage different from the first operating voltage to the SFP slot, so that the second SFP module is powered on to establish communication with the SFP slot.

[0010] In one embodiment, the first SFP module is the electrical module or the optical module; the second SFP module is the USB module of the SFP structure.

[0011] In one embodiment, when the module plugged into the SFP slot is the first SFP module, the detection circuit detects that the SFP slot provides two first-level signals, and the detection circuit controls the power supply circuit to provide the first operating voltage to the SFP slot according to the two first-level signals, so that the first SFP module is powered on to establish communication with the SFP slot.

[0012] In one embodiment, when the module plugged into the SFP slot is the second SFP module, the detection circuit detects that the SFP slot provides one first-level signal and one second-level signal, and the detection circuit controls the power supply circuit to provide the second operating voltage to the SFP slot according to the one first-level signal and one second-level signal, so that the second SFP module is powered on to establish communication with the SFP slot;

[0013] Wherein, one of the first-level signal and the second-level signal is a high-level signal, and the other is a low-level signal.

[0014] In one embodiment, the detection circuit includes a controller, and two input pins of the controller are respectively connected to the output pin and the detection pin of the SFP slot, and the controller is used to output a control signal for controlling the power supply circuit to change the voltage of the direct current output according to the two-level signals output by the output pin and the detection pin of the SFP slot.

[0015] In one embodiment, the power supply circuit includes a control end connected to the detection circuit and an output end connected to the SFP slot, and the control end of the power supply circuit changes the voltage of the direct current output by the output end according to the change of the control signal.

[0016] In one embodiment, the power supply circuit includes:

[0017] A switch circuit, connected to the controller, for switching between connecting the first operating voltage and connecting the second operating voltage according to the control signal;

[0018] An output circuit, connected to the switching circuit, for smoothing and filtering the first operating voltage or the second operating voltage and then outputting.

[0019] In one embodiment, the switching circuit includes a first switching transistor, a second switching transistor, a third switching transistor, a zener diode, a first resistor, and a second resistor;

[0020] The control terminal of the first switching transistor is connected to the detection circuit, the first conduction terminal of the first switching transistor is connected to the control terminal of the second switching transistor, and the second conduction terminal of the first switching transistor is grounded;

[0021] The first conduction terminal of the second switching transistor is connected to the operating power supply and is connected to the control terminal of the second switching transistor through the first resistor, the second conduction terminal of the second switching transistor is connected to the control terminal of the third switching transistor and is grounded through the second resistor;

[0022] The first conduction terminal of the third switching transistor is connected to the second operating voltage, and the second conduction terminal of the third switching transistor is connected to the input of the output circuit;

[0023] The anode of the zener diode is connected to the first operating voltage, and the cathode is connected to the input of the output circuit.

[0024] In one embodiment, the output circuit includes at least one output channel, and each output channel includes a filter inductor and a filter capacitor. One end of the filter inductor serves as the input of the output circuit, the other end serves as the output of the output circuit, and is grounded through the filter capacitor.

[0025] A second aspect of the embodiments of the present application provides a router, including an SFP slot and the front-end circuit of the above SFP slot.

[0026] In the above front-end circuit of the SFP slot and the router, the power supply voltage suitable for the module type currently plugged into the SFP interface can be determined by detecting the module type plugged into the SFP interface, so that the SFP slot and the module plugged into the SFP interface can communicate with each other, enabling an SFP interface to be compatible with USB (interface) modules, optical modules, and electrical modules, allowing the USB interface circuit and the SFP interface circuit to be reused, eliminating the need to separately design two different front-end circuits, reducing the area occupied by this part of the circuit on the PCB, and facilitating the overall layout design. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a schematic structural diagram of the front-end circuit of the SFP slot provided by the embodiments of the present application;

[0028] Figure 2Schematic diagram of the SFP slot;

[0029] Figure 3 is Figure 1 Example circuit schematic diagram of the power supply circuit in the front-end circuit shown. Detailed implementation manners

[0030] In order to make the technical problems, technical solutions and beneficial effects to be solved by this application clearer and more understandable, the following further details this application in combination with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain this application and are not used to limit this application.

[0031] It should be noted that when an element is referred to as "fixed to" or "disposed on" another element, it can be directly on the other element or indirectly on the other element. When an element is referred to as "connected to" another element, it can be directly connected to the other element or indirectly connected to the other element.

[0032] It should be understood that the orientation or positional relationship indicated by the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing this application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation to this application.

[0033] In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of this application, "a plurality of" means two or more, and "several" means one or more, unless otherwise specifically defined.

[0034] Please refer to Figure 1 , a front-end circuit of an SFP slot 10 provided by an embodiment of this application includes: a power supply circuit 20 and a detection circuit 30.

[0035] The power supply circuit 20 is coupled to the SFP slot 10 and is used to provide direct current;

[0036] The detection circuit 30 is connected to the SFP slot 10 and is used to detect the type of the module plugged into the SFP slot 10, and control the power supply circuit 20 to change the voltage of the output direct current to the SFP slot 10 according to the determined type of the module, so that the module is powered on and communicates with the SFP slot 10; the module includes an optical module, an electrical module and a USB module of SFP structure.

[0037] It can be understood that since the power supply voltages of the optical module and the electrical module are generally 3.3V, while the power supply voltage of the USB module with the SFP structure is generally 5V, therefore, the front-end circuit of the SFP slot 10 in this application realizes the detection of the insertion of the SFP slot 10 in the hardware circuit, identifies the inserted module, and then provides the corresponding voltage for power supply; after the inserted module is normally powered on, data communication can be realized through system configuration, thus realizing the self-adaptation of the inserted module.

[0038] Please refer to Figure 2 , which is the schematic diagram of the 20-pin SFP slot 10 specified by the SFP protocol, and the relevant introduction of the SFP slot 10 in this application is as follows:

[0039] (2) According to the SFP protocol definition, SFP1_SDA is the output pin of the SFP slot 10, SFP1_ABS is the detection pin of the SFP slot 10. When the SFP slot 10 is suspended, the output pin SFP1_SDA defaults to output a low level. When an identifiable optical / electrical module is inserted into the SFP slot 10, the output pin SFP1_SDA outputs a high level. When a USB module with the SFP structure is inserted into the SFP slot 10, the output pin SFP1_SDA outputs a low level.

[0040] (2) In the hardware circuit design, when the SFP slot 10 is suspended, the detection pin SFP1_ABS defaults to output a low level. After inserting an optical / electrical module with the SFP structure or a USB module with the SFP structure, the detection pin SFP1_ABS is pulled high to a high level by the relevant pins of the inserted module.

[0041] (3) The detection circuit 30, such as a controller (such as a CPU), controls the level of the control pin SFP_SW to switch the power supply voltage of the SFP slot 10 by detecting the level changes of the output pin SFP1_SDA and the detection pin SFP1_ABS. Generally, the output pin SFP1_SDA and the detection pin SFP1_ABS are respectively connected to two input pins of the controller. When the controller detects that both the output pin SFP1_SDA and the detection pin SFP1_ABS are at a low level or a high level, it controls the control pin SFP_SW to output a high level; when the CPU detects that the output pin SFP1_SDA and the detection pin SFP1_ABS are at a low level and a high level respectively, it controls the control pin SFP_SW to output a low level to realize changing the voltage of the direct current output by the power supply circuit 20.

[0042] Please refer to Figure 2 and Figure 3 , where Figure 2 and Figure 3 the pins with the same name should be connected to each other.

[0043] When the module plugged into the SFP slot 10 is an optical module, the detection circuit 30 controls the power supply circuit 20 to provide the first operating voltage VDD3.3 (3.3V) for the SFP slot 10, so that the first SFP module is powered on to establish communication with the SFP slot 10; when the module plugged into the SFP slot 10 is the second SFP module, the detection circuit 30 controls the power supply circuit 20 to provide the second operating voltage VDD5 (5V) different from the first operating voltage VDD3.3 (3.3V) for the SFP slot 10, so that the second SFP module is powered on to establish communication with the SFP slot 10. In this example, the first SFP module is an electrical module or an optical module; the second SFP module is a USB module with an SFP structure.

[0044] In an alternative embodiment, when the module plugged into the SFP slot 10 is an optical module, the detection circuit 30 will detect that the SFP slot 10 provides two first level signals (both low level or high level), and the detection circuit 30 controls the power supply circuit 20 to provide the first operating voltage VDD3.3 for the SFP slot 10 according to the two first level signals, so that the optical module is powered on to establish communication with the SFP slot 10.

[0045] In an alternative embodiment, when the module plugged into the SFP slot 10 is an electrical module, the detection circuit 30 detects that the SFP slot 10 provides two first level signals (both low level or high level), and the detection circuit 30 controls the power supply circuit 20 to provide the first operating voltage VDD3.3 for the SFP slot 10 according to the two first level signals, so that the electrical module is powered on to establish communication with the SFP slot 10.

[0046] When the module plugged into the SFP slot 10 is a USB module with an SFP structure, the detection circuit 30 detects that the SFP slot 10 provides a first level signal and a second level signal, and the detection circuit 30 controls the power supply circuit 20 to provide the second operating voltage VDD5 for the SFP slot 10 according to a first level signal and a second level signal, so that the USB module with an SFP structure is powered on to establish communication with the SFP slot 10; wherein, one of the first level signal and the second level signal is a high level signal, and the other is a low level signal.

[0047] By detecting the level states of the output pin SFP1_SDA and the detection pin SFP1_ABS, the type of the inserted module is judged, so as to control the control pin SFP_SW to switch the power supply system of the SFP slot 10 for the adaptive power supply of the module, so that the SFP slot 10 can be compatible with the use of the USB module with an SFP structure.

[0048] In one embodiment, the power supply circuit 20 includes a control end connected to the detection circuit 30 and an output end connected to the SFP slot 10. The control end of the power supply circuit 20 changes the voltage of the direct current output at the output end according to the change of the control signal. The power supply circuit 20 can be implemented by simple switching devices or by a switching power supply circuit.

[0049] Please refer to Figure 3 , in one embodiment, the power supply circuit 20 includes a switching circuit 22 and an output circuit 24.

[0050] The switching circuit 22 is connected to the control pin SFP_SW of the controller and is used to switch between connecting the first working voltage VDD3.3 and connecting the second working voltage VDD5 according to the control signal. It can be implemented by MOS transistors, bipolar transistors, relays, or transformers. Now, one implementable circuit using a P-type MOS transistor as the switch is provided. The output circuit 24 is connected to the switching circuit 22 and is used to output the first working voltage VDD3.3 or the second working voltage VDD5 after smoothing and filtering. The power supply circuit 20 is simple and has a low cost.

[0051] In one embodiment, the switching circuit 22 includes a first switching transistor Q1, a second switching transistor Q2, a third switching transistor Q3, a zener diode D1, a first resistor R1, an output capacitor C1, and a second resistor R2.

[0052] The control end of the first switching transistor Q1 is connected to the detection circuit 30. The first conducting end of the first switching transistor Q1 is connected to the control end of the second switching transistor Q2, and the second conducting end of the first switching transistor Q1 is grounded. The first conducting end of the second switching transistor Q2 is connected to the working power supply and is connected to the control end of the second switching transistor Q2 through the first resistor R1. The second conducting end of the second switching transistor Q2 is connected to the control end of the third switching transistor Q3 and is grounded through the second resistor R2. The first conducting end of the third switching transistor Q3 is connected to the second working voltage VDD5, and the second conducting end of the third switching transistor Q3 is connected to the input of the output circuit 24. The anode of the zener diode D1 is connected to the first working voltage VDD3.3, the cathode is connected to the input of the output circuit 24, and is grounded through the output capacitor C1.

[0053] The first switching transistor Q1 is an NPN bipolar transistor or an N-type MOS transistor. The second switching transistor Q2 and the third switching transistor Q3 are P-type MOS transistors, or can be PNP bipolar transistors or IGBT transistors.

[0054] The switching circuit 22 can perform adaptive power supply for the inserted module, adds protection to the first working voltage VDD3.3 power supply, can perform adaptive power supply for different modules when switching modules under the user scenario while ensuring that the hardware circuit of the module will not be irreversibly damaged during the process of switching modules.

[0055] In one embodiment, the output circuit 24 includes at least one output channel 241. Each output channel 241 includes a filtering inductor L1 and a filtering capacitor C2. One end of the filtering inductor C2 serves as the input of the output circuit 24, and the other end serves as the output of the output circuit 24, and is grounded through the filtering capacitor C2.

[0056] The logic control is shown in Table 1, and the circuit implementation is as Figure 2 、 Figure 3 shown:

[0057] Table 1

[0058]

[0059] When no module is inserted into the SFP slot 10, at this time, SFP1_SDA and SFP1_ABS default to low level, SFP_SW defaults to output high level, the first switching transistor Q1 conducts, the second switching transistor Q2 (Vgs < 0V) conducts, and the third switching transistor Q3 is off (Vgs = 0). At this time, the SFP slot 10 is powered by 3.3V, and the insertion detection module is in the listening state;

[0060] When an optical module / electrical module is inserted into the SFP slot 10, SFP1_SDA and SFP1_ABS are pulled high to high level, SFP_SW defaults to output high level, the first switching transistor Q1 conducts, the second switching transistor Q2 (Vgs < 0V) conducts, and the third switching transistor Q3 is off (Vgs = 0). At this time, the power supply circuit 20 provides a working voltage of 3.3V, and the system adapts to convert the SFP slot 10 and the optical / electrical module into an optical port / electrical port for use;

[0061] When a USB module with an SFP structure is inserted into the SFP slot 10, the pins of the SFP slot 10 are connected to the USB power supply (VCC) in the USB module with an SFP structure to distinguish the levels from other modules, thereby implementing the detection function. SFP1_ABS is pulled high to high level, and SFP1_SDA remains low level. At this time, the detection circuit 30 controls SFP_SW to output low level, the second switching transistor Q2 (Vgs = 0V) is off, and the third switching transistor Q3 conducts (Vgs < 0). At this time, the power supply circuit 20 provides a working voltage of 5V, and the system adapts to convert the SFP slot 10 and the USB module with an SFP structure into a USB interface for use;

[0062] When any inserted module is unplugged, SFP1_SDA resumes the default low level, SFP1_ABS resumes the default low level, SFP_SW outputs a high level, the third switching transistor Q3 is turned off (Vgs = 0), the output of the second working voltage VDD5 power supply module is suspended, and the first working voltage VDD3.3 is provided by default for the next inserted module to prevent damage to the inserted optical module / electrical module under the second working voltage VDD5.

[0063] The second aspect of the embodiment of the present application provides a router, including an SFP slot 10 and the front-end circuit of the SFP slot 10 described above.

[0064] Based on the router with the SFP slot 10, compatibility with the USB module of the SFP structure of the SFP slot 10 is achieved. When no module is inserted into the SFP slot 10, it does not affect the normal operation of the router; when any SFP structure module (optical module, electrical module or USB module of the SFP structure) is inserted, the module type can be judged by the insertion detection circuit 30, and the corresponding working voltage is provided, and then system adaptation is performed to convert the SFP slot 10 and the inserted module into corresponding interfaces (optical port, electrical port, USB interface); when pulling out a module that has been powered on normally, the pulling out action resets the power supply system, and the detection module resumes the listening state, realizing the self-adaptation of the inserted module to meet the diverse functional interface requirements of users.

[0065] Provide a router with an SFP slot 10 that is compatible with optical modules, electrical modules and USB modules of the SFP structure at the same time, which can meet the user's needs for using optical ports, electrical ports and USB interfaces at the same time, and there is no such product on the market. This router is based on the router with the SFP slot 10. On the basis of supporting optical / electrical modules, it is compatible with the USB module of the SFP structure by changing the circuit design, making up for the disadvantages of low utilization rate of the SFP slot 10, high threshold for using optical modules, and waste of electrical port module rate, etc., and can greatly meet the user's needs for using USB ports. Users only need to insert the USB module of the SFP structure on the SFP slot 10 to conveniently use functions such as network printing, downloading (connecting a mobile hard disk), charging, and home network sharing through the USB port.

[0066] The above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements for some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application, and should all be included in the protection scope of the present application.

Claims

1. A front-end circuit of an SFP slot, characterized in that Including: A power supply circuit, coupled to the SFP slot, for providing direct current power; A detection circuit, connected to the SFP slot, for detecting the type of the module plugged into the SFP slot, and controlling the power supply circuit to change the voltage of the direct current power output to the SFP slot according to the determined type of the module, so that the module is powered on to establish communication with the SFP slot; when the inserted module is unplugged, the power supply circuit defaults to providing a first operating voltage to the SFP slot; The module includes an optical module, an electrical module, and a USB module in the SFP structure; The detection circuit includes a controller, and two input pins of the controller are respectively connected to the output pin and the detection pin of the SFP slot. The controller is used to output a control signal for controlling the power supply circuit to change the voltage of the direct current power output according to two level signals output from the output pin and the detection pin of the SFP slot; The power supply circuit includes: A switching circuit, connected to the controller, for switching between connecting the first operating voltage and connecting the second operating voltage according to the control signal; An output circuit, connected to the switching circuit, for smoothing and filtering the first operating voltage or the second operating voltage and then outputting; The switching circuit includes a first switching tube, a second switching tube, a third switching tube, a voltage stabilizing diode, a first resistor, and a second resistor; The control end of the first switching tube is connected to the detection circuit, the first conducting end of the first switching tube is connected to the control end of the second switching tube, and the second conducting end of the first switching tube is grounded; The first conducting end of the second switching tube is connected to the working power supply and is connected to the control end of the second switching tube through the first resistor. The second conducting end of the second switching tube is connected to the control end of the third switching tube and is grounded through the second resistor; The first conducting end of the third switching tube is connected to the second operating voltage, and the second conducting end of the third switching tube is connected to the input of the output circuit; The anode of the voltage stabilizing diode is connected to the first operating voltage, and the cathode is connected to the input of the output circuit.

2. The front-end circuit according to claim 1, characterized in that, When the module plugged into the SFP slot is a first SFP module, the detection circuit controls the power supply circuit to provide a first operating voltage to the SFP slot, so that the first SFP module is powered on to establish communication with the SFP slot; When the module plugged into the SFP slot is a second SFP module, the detection circuit controls the power supply circuit to provide a second operating voltage different from the first operating voltage to the SFP slot, so that the second SFP module is powered on to establish communication with the SFP slot.

3. The front-end circuit according to claim 2, wherein The first SFP module is the electrical module or the optical module; the second SFP module is the USB module in the SFP structure.

4. The front-end circuit according to claim 2 or 3, characterized in that When the module plugged into the SFP slot is the first SFP module, the detection circuit detects that the SFP slot provides two first-level signals, and the detection circuit controls the power supply circuit to provide the first operating voltage for the SFP slot according to the two first-level signals, so that the first SFP module is powered on to establish communication with the SFP slot.

5. The front-end circuit according to claim 2 or 3, characterized in that, When the module plugged into the SFP slot is the second SFP module, the detection circuit detects that the SFP slot provides one first-level signal and one second-level signal, and the detection circuit controls the power supply circuit to provide the second operating voltage for the SFP slot according to the one first-level signal and one second-level signal, so that the second SFP module is powered on to establish communication with the SFP slot; Wherein, one of the first-level signal and the second-level signal is a high-level signal, and the other is a low-level signal.

6. The front-end circuit according to claim 1, wherein The power supply circuit includes a control end connected to the detection circuit and an output end connected to the SFP slot, and the control end of the power supply circuit changes the voltage of the direct current output by the output end according to the change of the control signal.

7. The front-end circuit according to claim 1, wherein The output circuit includes at least one output channel, each output channel includes a filtering inductor and a filtering capacitor, one end of the filtering inductor is used as the input of the output circuit, the other end is used as the output of the output circuit, and is grounded through the filtering capacitor.

8. A router, including an SFP slot, characterized in that, It further includes the front-end circuit of the SFP slot according to any one of claims 1 to 7.

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