Power reception device and ethernet system
By connecting the first switch circuit in the power receiving device in parallel to control its conduction and disconnection, the problem of lightning protection circuit in the prior art is easily broken down, and the safety and reliability of the equipment are improved.
Patent Information
- Application Number
- CN202311244279.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2023-09-25
- Publication Date
- 2025-03-25
AI Technical Summary
The lightning protection circuit of existing electronic products is easily penetrated when facing large lightning strikes, resulting in damage to the rectifier and charging chip, and unable to effectively protect the power-receiving equipment.
A power receiving device is designed, and a rectifier circuit is used to rectify the input power signal and output it to the PD chip, and a first switching circuit is connected in parallel outside the PD chip. By controlling the on and off of the switching circuit, the common mode burst current during lightning strike is prevented from flowing into the PD chip.
It effectively improves the safety and reliability of power-receiving equipment, prevents lightning strikes from damaging the PD chip, and enhances the protection ability of lightning strikes.
Smart Images
Figure CN119695816A_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the field of vehicles, and in particular to a powered device and an Ethernet system. Background Art
[0002] The functions of current electronic devices (such as computers, mobile phones, outdoor wireless base stations, etc.) are increasing, and the hardware is becoming more and more loaded, requiring higher power to support in order to meet the operation requirements of electronic devices. Therefore, the lightning strike standards for electronic products are also becoming higher and higher.
[0003] At present, the lightning protection circuit of electronic products includes a lightning surge protection circuit, a rectifier (Bridge) and a power receiving chip set on the primary side of the transformer. Among them, it can be seen that the lightning surge protection circuit provides the main lightning protection, but the common-mode lightning current will flow through the rectifier (Bridge), the charging chip and the capacitor to the ground wire (PE). The size of the common-mode lightning current is related to the capacitance value used and the lightning voltage. Most of the rectifiers currently used are discrete FETs or active bridges, which have low current resistance and are easily penetrated when encountering large lightning strikes (above 4kV). And the field effect transistor inside the charging chip is also not very current-resistant and is easily broken down by lightning. Summary of the invention
[0004] In order to solve the problems in the prior art, the present application provides a powered device and an Ethernet system to improve the safety and reliability of the powered device.
[0005] The present application provides a powered device, the powered device comprising:
[0006] Communication interface, used for transmitting data signals and power signals;
[0007] A surge protection circuit, electrically connected to the communication interface, for absorbing peak current in the power supply signal;
[0008] A rectifier circuit, wherein an input end of the rectifier circuit is electrically connected to the communication interface; the rectifier circuit is used to convert a power supply signal connected to the communication interface into a first DC signal output;
[0009] A PD chip, the PD chip is electrically connected to the output end of the rectifier circuit and the communication interface respectively; the PD chip is used to communicate with the power supply device according to the data signal;
[0010] A first switch circuit is connected in parallel with the PD chip;
[0011] A control circuit is electrically connected to the first switch circuit; the control circuit is used to control the first switch circuit to be turned on when the PD chip and the power supply device successfully communicate and negotiate, and to control the first switch circuit to be turned off when the voltage value of the first DC signal is less than a first preset voltage value.
[0012] In one embodiment, the communication interface includes a first chip and a first transformer, wherein the first chip is electrically connected to the primary side of the first transformer; the first chip is used to transmit data signals and power signals;
[0013] The surge protection circuit comprises:
[0014] A first protector, the first protector is connected in parallel with the primary side of the first transformer; the first protector is used to be turned on when the voltage value of the power supply signal is greater than a second preset voltage value;
[0015] A second protector, wherein the first end of the second protector is electrically connected to the first protector, and the second end of the second protector is grounded; the second protector is used to be turned on when the voltage value of the power supply signal is greater than a second preset voltage value.
[0016] In one embodiment, the communication interface includes a first chip and a first transformer, wherein the first chip is electrically connected to the primary side of the first transformer; the first chip is used to transmit data signals and power signals;
[0017] The surge protection circuit comprises:
[0018] A third protector, wherein the first end of the third protector is electrically connected to the center tap of the primary side of the transformer, and the second end of the third protector is grounded; the third protector is used to be turned on when the voltage value of the power supply signal is greater than a third preset voltage value.
[0019] In one embodiment, the first protector is a gas discharge tube; the second protector is any one of a metal oxide varistor, a bidirectional transient overvoltage protector, and a transient diode.
[0020] In one embodiment, the number of the first transformers is multiple, and the number of the first protectors and the second protectors is consistent with the number of the first transformers.
[0021] In one embodiment, the rectifier circuit includes a first diode, a second diode, a first MOS transistor and a second MOS transistor; the first end of the first diode is electrically connected to the first end of the first MOS transistor to constitute the first input end of the rectifier circuit, the second end of the first diode is electrically connected to the first end of the second diode to constitute the first output end of the rectifier circuit, the second end of the second diode is electrically connected to the first end of the second MOS transistor to constitute the second input end of the rectifier circuit, and the second end of the first MOS transistor is electrically connected to the second end of the second MOS transistor to constitute the second output end of the rectifier circuit.
[0022] In one embodiment, the first switch circuit includes a third MOS transistor.
[0023] In one embodiment, the powered device further includes:
[0024] A second transformer, wherein the primary side of the second transformer is electrically connected to the output end of the rectifier circuit; the second transformer is used to transmit the first DC signal.
[0025] In one embodiment, the powered device further includes:
[0026] A first capacitor, wherein a first end of the first capacitor is electrically connected to the PD chip, and a second end of the first capacitor is grounded.
[0027] The present application also proposes an Ethernet system, including a power supply device and the above-mentioned powered device.
[0028] The present application rectifies the input power signal through a rectifier circuit and outputs it to the PD chip, so that the PD chip can work normally. By connecting the first switch circuit in parallel to the outside of the PD chip, the common-mode surge current during lightning strikes passes through the first switch circuit, thereby preventing the PD chip from being damaged by the large current and improving the safety and reliability of the powered device. BRIEF DESCRIPTION OF THE DRAWINGS
[0029] Figure 1 It is a structural schematic diagram of an embodiment of a powered device of the present application.
[0030] Figure 2 It is a structural schematic diagram of an embodiment of a first switch circuit of the present application.
[0031] Figure 3 Schematic diagram of the structure of a surge protection circuit according to an embodiment of the present application.
[0032] Figure 4 FIG. 1 is a schematic structural diagram of another embodiment of the surge protection circuit of the present application.
[0033] Figure 5 It is a structural schematic diagram of an embodiment of a rectifier circuit of the present application.
[0034] Figure 6 This is a schematic diagram of the structure of an Ethernet system according to an embodiment of the present application.
[0035] Main component symbols
[0036] Power receiving device 100 Communication interface 110
[0037] Surge protection circuit 120 Rectification circuit 130
[0038] PD chip 140 First switch circuit 150
[0039] Control circuit 160 First diode D1
[0040] The second diode D2 The first MOS tube Q1
[0041] The second MOS tube Q2 The third MOS tube Q3
[0042] First chip U1 First transformer T1
[0043] The first protector 121 and the second protector 122
[0044] The third protector 123 The second transformer T2
[0045] First capacitor Y power supply device 200
[0046] The following specific implementation methods will further illustrate the present application in conjunction with the above-mentioned drawings. DETAILED DESCRIPTION
[0047] The following description will refer to the accompanying drawings to more fully describe the content of the present application. Shown in the accompanying drawings are exemplary embodiments of the present application. However, the present application can be implemented in many different forms and should not be construed as being limited to the exemplary embodiments set forth herein. These exemplary embodiments are provided to make the present application thorough and complete, and to fully convey the scope of the present application to those skilled in the art. Similar reference numerals represent identical or similar components.
[0048] The terms used herein are only used for the purpose of describing specific exemplary embodiments and are not intended to limit the present application. As used herein, unless the context clearly indicates otherwise, the singular forms "a", "an" and "the" are intended to also include the plural forms. In addition, when used herein, "including" and / or "comprising" and / or "having", integers, steps, operations, components and / or components, but do not exclude the existence or addition of one or more other features, regions, integers, steps, operations, components and / or groups thereof.
[0049] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by those of ordinary skill in the art to which this application belongs. In addition, unless explicitly defined herein, terms such as those defined in general dictionaries should be interpreted as having a meaning consistent with their meaning in the relevant technology and the content of this application, and will not be interpreted as an idealized or overly formal meaning.
[0050] The following will describe exemplary embodiments in conjunction with the accompanying drawings. It should be noted that the components depicted in the reference drawings are not necessarily shown to scale; and the same or similar components will be given the same or similar reference numerals or similar technical terms.
[0051] Reference Figure 1 The present application proposes a powered device 100, which includes a communication interface 110, a surge protection circuit 120, a rectifier circuit 130, a powered device 100 (PD) chip, a first switch circuit 150 and a control circuit 160. The PD chip 140 may refer to a main control chip of the powered device 100.
[0052] The communication interface 110 is used to transmit data signals and power signals.
[0053] The surge protection circuit 120 is electrically connected to the communication interface 110 and is used to absorb the peak current in the power signal.
[0054] The input end of the rectifier circuit 130 is electrically connected to the communication interface 110 ; the rectifier circuit 130 is used to convert the power signal received by the communication interface 110 into a first DC signal for output.
[0055] The PD chip 140 is electrically connected to the output end of the rectifier circuit 130 and the communication interface 110. The PD chip 140 is used to communicate with the power supply device 200 according to the data signal.
[0056] The first switch circuit 150 is connected in parallel with the PD chip 140 .
[0057] The control circuit 160 is electrically connected to the first switch circuit 150; the control circuit 160 is used to control the first switch circuit 150 to be turned on when the communication negotiation between the PD chip 140 and the power supply device 200 is successful, and to control the first switch circuit 150 to be turned off when the voltage value of the first DC signal is less than a first preset voltage value.
[0058] In this embodiment, the communication interface 110 can be an Ethernet interface or a local area network interface. The communication interface 110 is used to electrically connect to the power supply equipment 200 (Power Sourcing Equipment, PSE) to transmit data signals and power signals. The PD chip 140 communicates with the power supply equipment 200 by transmitting data signals through the communication interface 110 to complete the handshake. The power signal is input to the rectifier circuit 130 by the communication interface 110, and the rectifier circuit 130 converts the power signal into a first DC signal and outputs it to the PD chip 140, the control circuit 160 and other functional circuits for power supply. If the voltage value of the power signal is greater than the second preset voltage value, the surge protection circuit 120 will be turned on instantaneously, and the surge current will be conducted to the ground line to protect the rectifier circuit 130, the PD chip 140, the control circuit 160 and other functional circuits from being damaged by lightning.
[0059] When a lightning strike occurs, part of the common-mode current of the lightning strike is absorbed by the surge protection circuit 120, and part of it flows into the rectifier circuit 130. The common-mode current flowing into the rectifier circuit 130 will flow through the PD chip 140 and then to the ground line, causing the transistors and other small current devices inside the PD chip 140 to be burned. Figure 2 In this application, the first switch circuit 150 is connected in parallel to the outside of the PD chip 140. Before the PD chip 140 and the power supply device 200 complete the communication negotiation (communication negotiation based on the handshake protocol), the control circuit 160 controls the first switch circuit 150 to be disconnected; after the PD chip 140 and the power supply device 200 complete the communication negotiation, the control circuit 160 controls the first switch circuit 150 to be turned on. At this time, if the current of the communication interface 110 is too large, the common-mode surge current will flow through the rectifier circuit 130 and the first switch circuit 150, and will not flow into the PD chip 140, thereby preventing the PD chip 140 from being damaged by the large current. When the power supply voltage of the PD chip 140 is less than the minimum operating voltage (for example, the powered device 100 is turned off), the control circuit 160 controls the first switch circuit 150 to be disconnected to reduce circuit loss. Among them, the control circuit 160 can determine whether the PD chip 140 has completed the communication negotiation with the power supply device 200 by directly obtaining the data signal of the communication interface 110, or the PD chip 140 outputs a notification message to the control circuit 160 after completing the communication negotiation with the power supply device 200, and the control circuit 160 can respond to the notification message to control the first switch circuit 150 to be turned on. The control circuit 160 can be implemented by using chips such as a microprocessor, FPGA (Field Programmable Gate Array), etc. The first switch circuit 150 can use a transistor, such as a PMOS tube, an NMOS tube, etc. For example, the first switch circuit 150 includes a third MOS tube Q3, the drain and source of the third MOS tube Q3 are electrically connected to the PD chip 140 respectively, and the gate of the third MOS tube Q3 is electrically connected to the control circuit 160.
[0060] The present application rectifies the input power signal through the rectifier circuit 130 and outputs it to the PD chip 140, so that the PD chip 140 can work normally. By connecting the first switch circuit 150 in parallel to the outside of the PD chip 140, the common-mode surge current during lightning strike passes through the first switch circuit 150, thereby preventing the PD chip 140 from being damaged by the large current, thereby improving the safety and reliability of the powered device 100.
[0061] Reference Figure 3 In one embodiment, the communication interface 110 includes a first chip U1 and a first transformer T1, wherein the first chip U1 is electrically connected to the primary side of the first transformer T1; the first chip U1 is used to transmit data signals and power signals.
[0062] The surge protection circuit 120 includes a first protector 121 and a second protector 122 .
[0063] The first protector 121 is connected in parallel with the primary side of the first transformer T1 ; the first protector 121 is used to be turned on when the voltage value of the power signal is greater than a second preset voltage value.
[0064] The first end of the second protector 122 is electrically connected to the first protector 121 , and the second end of the second protector 122 is grounded; the second protector 122 is configured to be turned on when the voltage value of the power signal is greater than a second preset voltage value.
[0065] In this embodiment, the first protector 121 is connected in parallel with the primary side of the first transformer T1, that is, connected in parallel with the corresponding two pins on the first chip U1. For example, the primary side of the first transformer T1 is connected to the TX1 pin and the RX1 pin of the first chip U1, and the first protector 121 is connected in parallel with the primary side of the first transformer T1, that is, connected in parallel with the TX1 pin and the RX1 pin of the first chip U1. When a lightning strike occurs, the first protector 121 is turned on to short-circuit the primary side of the first transformer T1 and the TX1 pin and the RX1 pin of the first chip U1, so that a large current flows from the first protector 121 and the second protector 122 into the ground line, thereby preventing the first chip U1, the first transformer T1 and the subsequent circuit from being damaged by the large current. Among them, the first protector 121 can be a gas discharge tube. The second protector 122 can be any one of a metal oxide varistor, a bidirectional transient overvoltage protector, and a transient diode.
[0066] Reference Figure 4In another embodiment, the surge protection circuit 120 includes a third protector 123. A first end of the third protector 123 is electrically connected to the center tap of the primary side of the transformer, and a second end of the third protector 123 is grounded; the third protector 123 is used to be turned on when the voltage value of the power signal is greater than a third preset voltage value.
[0067] In this embodiment, when a lightning strike occurs, the third protector 123 is instantly turned on to introduce a large current into the ground line to prevent the first transformer T1 and the subsequent circuit from being damaged by the large current. In this embodiment, surge protection can be achieved through the third protector 123, the structure is simple, and the number of protectors used is small. Among them, the third protector 123 can be any one of a metal oxide varistor, a bidirectional transient overvoltage protector, and a transient diode.
[0068] In one embodiment, the number of the first transformers T1 is multiple, and the number of the first protectors 121 and the second protectors 122 is consistent with the number of the first transformers T1. In this way, protection of multiple first transformers T1 and multiple pins of the first chip U1 can be achieved.
[0069] Reference Figure 5 In one embodiment, the rectifier circuit 130 includes a first diode D1, a second diode D2, a first MOS transistor Q1, and a second MOS transistor Q2; the first end of the first diode D1 is electrically connected to the first end of the first MOS transistor Q1 to form a first input end of the rectifier circuit 130, the second end of the first diode D1 is electrically connected to the first end of the second diode D2 to form a first output end of the rectifier circuit 130, the second end of the second diode D2 is electrically connected to the first end of the second MOS transistor Q2 to form a second input end of the rectifier circuit 130, and the second end of the first MOS transistor Q1 is electrically connected to the second end of the second MOS transistor Q2 to form a second output end of the rectifier circuit 130.
[0070] In this embodiment, when the current / voltage of the communication interface 110 fluctuates greatly (for example, a lightning strike occurs), the operation of the surge protection circuit 120 causes the voltage of the communication interface 110 to change instantly (the surge voltage can be below 90V, but the voltage may sometimes drop to 0V instantly). The existing full-bridge rectifier is composed of field effect transistors, which will transmit the voltage fluctuation to the next-level PD chip 140, causing the PD chip 140 to malfunction and be damaged. The rectifier circuit 130 of this embodiment utilizes the unidirectional conduction characteristics of the first diode D1 and the second diode D2 to prevent the voltage fluctuation from being transmitted to the PD chip 140 when the voltage of the communication interface 110 changes instantly, thereby preventing the PD chip 140 from being damaged by the voltage fluctuation. Among them, the number of rectifier circuits 130 can be multiple.
[0071] In one embodiment, the powered device 100 further includes a second transformer T2, the primary side of the second transformer T2 is electrically connected to the output end of the rectifier circuit 130; the second transformer T2 is used to transmit the first DC signal.
[0072] In this embodiment, the first DC signal output by the rectifier circuit 130 is transmitted to the subsequent circuit through the second transformer T2, which has the functions of step-up and step-down and safety isolation. When an abnormality occurs on the primary side or the secondary side of the second transformer T2, it will not affect the normal power consumption of the other side.
[0073] In one embodiment, the powered device 100 further includes a first capacitor Y, a first end of the first capacitor Y is electrically connected to the PD chip 140, and a second end of the first capacitor Y is grounded. The magnitude of the lightning common-mode current is related to the capacitance value of the first capacitor Y and the lightning voltage. The lightning common-mode current can be limited to a suitable range by selecting a suitable capacitance value to prevent the lightning common-mode current from being too large and damaging the circuit.
[0074] Reference Figure 6 The present application also proposes an Ethernet system, including a power supply device 200 and the above-mentioned powered device 100.
[0075] The detailed structure of the powered device 100 may refer to the above-mentioned embodiment, which will not be described in detail here. It can be understood that since the above-mentioned powered device 100 is used in the Ethernet system of the present invention, the embodiment of the Ethernet system of the present invention includes all technical solutions of all embodiments of the above-mentioned powered device 100, and the technical effects achieved are also exactly the same, which will not be described in detail here.
[0076] In the above, the specific implementation of the present application is described with reference to the accompanying drawings. However, those skilled in the art will appreciate that various changes and substitutions may be made to the specific implementation of the present application without departing from the spirit and scope of the present application. These changes and substitutions are all within the scope defined by the present application.
Claims
1. A power receiving device, characterized in that: The powered device comprises: Communication interface, used for transmitting data signals and power signals; A surge protection circuit, electrically connected to the communication interface, for absorbing peak current in the power supply signal; A rectifier circuit, wherein an input end of the rectifier circuit is electrically connected to the communication interface; the rectifier circuit is used to convert a power supply signal connected to the communication interface into a first DC signal output; A PD chip, the PD chip is electrically connected to the output end of the rectifier circuit and the communication interface respectively; the PD chip is used to communicate with the power supply device according to the data signal; A first switch circuit is connected in parallel with the PD chip; A control circuit is electrically connected to the first switch circuit; the control circuit is used to control the first switch circuit to be turned on when the PD chip and the power supply device successfully communicate and negotiate, and to control the first switch circuit to be turned off when the voltage value of the first DC signal is less than a first preset voltage value.
2. The power receiving device according to claim 1, characterized in that: The communication interface includes a first chip and a first transformer, wherein the first chip is electrically connected to the primary side of the first transformer; the first chip is used to transmit data signals and power signals; The surge protection circuit comprises: A first protector, the first protector is connected in parallel with the primary side of the first transformer; the first protector is used to be turned on when the voltage value of the power supply signal is greater than a second preset voltage value; A second protector, wherein the first end of the second protector is electrically connected to the first protector, and the second end of the second protector is grounded; the second protector is used to be turned on when the voltage value of the power supply signal is greater than a second preset voltage value.
3. The power receiving device according to claim 1, characterized in that: The communication interface includes a first chip and a first transformer, wherein the first chip is electrically connected to the primary side of the first transformer; the first chip is used to transmit data signals and power signals; The surge protection circuit comprises: A third protector, wherein the first end of the third protector is electrically connected to the center tap of the primary side of the transformer, and the second end of the third protector is grounded; the third protector is used to be turned on when the voltage value of the power supply signal is greater than a third preset voltage value.
4. The power receiving device according to claim 2, characterized in that: The first protector is a gas discharge tube; the second protector is any one of a metal oxide varistor, a bidirectional transient overvoltage protector, and a transient diode.
5. The power receiving device according to claim 2, characterized in that: The number of the first transformers is multiple, and the number of the first protectors and the second protectors is consistent with the number of the first transformers.
6. The power receiving device according to claim 1, characterized in that: The rectifier circuit includes a first diode, a second diode, a first MOS transistor and a second MOS transistor; the first end of the first diode is electrically connected to the first end of the first MOS transistor to form a first input end of the rectifier circuit, the second end of the first diode is electrically connected to the first end of the second diode to form a first output end of the rectifier circuit, the second end of the second diode is electrically connected to the first end of the second MOS transistor to form a second input end of the rectifier circuit, and the second end of the first MOS transistor is electrically connected to the second end of the second MOS transistor to form a second output end of the rectifier circuit.
7. The power receiving device according to claim 1, characterized in that: The first switch circuit includes a third MOS transistor.
8. The power receiving device according to claim 1, characterized in that: The powered device further comprises: A second transformer, wherein the primary side of the second transformer is electrically connected to the output end of the rectifier circuit; the second transformer is used to transmit the first DC signal.
9. The power receiving device according to claim 1, characterized in that: The powered device further comprises: A first capacitor, wherein a first end of the first capacitor is electrically connected to the PD chip, and a second end of the first capacitor is grounded.
10. An Ethernet system, characterized in that: The invention comprises a power supply device and a power receiving device as claimed in any one of claims 1 to 9.