CN107332675B

CN107332675B - PoE equipment without network transformer

Info

Publication number: CN107332675B
Application number: CN201710639940.9A
Authority: CN
Inventors: 李汝虎; 蔡舒宏; 常飞
Original assignee: Bowei Technology Co ltd
Current assignee: Bowei Technology Co ltd
Priority date: 2017-07-31
Filing date: 2017-07-31
Publication date: 2023-05-02
Anticipated expiration: 2037-07-31
Also published as: CN107332675A

Abstract

The invention relates to the technical field of Ethernet, in particular to a PoE device without a network transformer, which comprises: the device comprises a chip with PHY function, a signal processing module, a high-voltage isolation circuit and an RJ45 connector; the chip with PHY function is connected with the high-voltage isolation circuit through the signal processing module; the high-voltage isolation circuit is connected with the RJ45 connector; the isolation circuit is connected with the power input of the PoE power supply equipment or the power output of the power receiving equipment, and the RJ45 connector is connected with the PoE equipment. The PoE equipment without the network transformer provided by the invention does not contain a network transformer, only has discrete electronic devices arranged by the signal processing module, has flexible layout and wiring, reduces the cost and the board layout space, is beneficial to miniaturization, portable design and user experience of products, can be used in application scenes of some limited space or modern intelligent buildings, and is convenient for popularization and application of the equipment.

Description

PoE equipment without network transformer

Technical Field

The invention relates to the technical field of Ethernet, in particular to PoE equipment without a network transformer.

Background

The industry standards for PoE are mainly IEEE802.3 af and IEEE802.3at, supporting a maximum PD power consumption of 25.5w. In addition, there is also nonstandard LTPoE++ proposed by Linear corporation, which is widely used and supports PD power consumption up to 90 w. The PoE network transformer is connected between the PHY port and the RJ45 connector, and one of the PoE network transformer is used for realizing the electrical isolation between the chip with the PHY function and the outside, and the PoE network transformer is protected from lightning and avoiding the chip with the PHY function from being damaged by lightning; the second is used for common mode rejection, coupling differential mode components, enabling signals to be transmitted without distortion, and supporting long-distance communication of 100 m; thirdly, poE power supply output or power receiving input is supported, data communication is carried out simultaneously, and PoE high voltage and a chip with PHY function are isolated. For the above reasons, current common PoE devices do not depart from the use of PoE network transformers. Along with the market demand for high-power PD load, the PoE network transformer must meet the capability of supporting high-current output, has high customization cost and large volume, and is unfavorable for the miniaturized design and application popularization of equipment. In addition, all PoE devices are connected in a butt joint manner through a communication link of a chip with a PHY function, a PoE network transformer, an RJ45 connector, a network cable, an RJ45 connector, a PoE network transformer and a chip with a PHY function, and the PoE device comprises at least two PoE network transformers, particularly for a router or a hub, which is similar to the PoE device needing to provide a plurality of external ports, the cost is high, and a large amount of board layout area is occupied.

Disclosure of Invention

The invention provides the PoE equipment without the network transformer, which solves the technical problems of high cost and large occupied space caused by the adoption of the network transformer in the PoE equipment in the prior art, and the technical problems that a signal processing circuit in a low-voltage area and a chip with a PHY function are broken down by high voltage if the network transformer is not used. The PoE equipment without the network transformer is adopted, the cost and the board distribution space are reduced, the popularization and the application of the PoE equipment and other expansion functions are conveniently realized, and a signal processing circuit in a low-voltage area and a chip with PHY (physical layer) function can be prevented from being broken down by high voltage after high-voltage isolation treatment.

The invention provides PoE equipment without a network transformer, which comprises a chip with PHY function, a signal processing module, a high-voltage isolation circuit and an RJ45 connector;

the chip with the PHY function is connected with the high-voltage isolation circuit through the signal processing module;

the high-voltage isolation circuit is connected with the RJ45 connector;

the high-voltage isolation circuit is connected with the power input of the PoE power supply equipment or the power output of the power receiving equipment, and the RJ45 connector is connected with the PoE power supply or the power receiving equipment.

Further, the signal processing module includes: a coupling circuit;

a P line port and an N line port are arranged in the chip with the PHY function, the P line port and the N line port form a data differential pair, and the number of the accessed differential pairs is selected according to the connection rate requirement;

the signal processing module comprises a first P line input and output port, a first N line input and output port, a second P line input and output port and a second N line input and output port; the first P line input and output port and the first N line input and output port form a data differential line pair, and the second P line input and output port and the second N line input and output port form a data differential line pair; the signal processing module can select the number of the access differential pairs according to the connection rate requirement;

the RJ45 connector comprises a first network port and a second network port;

the P line port is connected with the first P line input and output port, and the first P line input and output port is connected with the coupling circuit; the coupling circuit is connected with the second P line input and output port; the second P line input and output port is connected with the first network interface through the high-voltage isolation circuit;

the N-line port is connected with the first N-line input and output port, and the first N-line input and output port is connected with the coupling circuit; the coupling circuit is connected with the second N-line input and output port; the second N-wire input and output port is connected with the second network interface through the high-voltage isolation circuit.

Further, the signal processing module further includes: a lightning strike protection circuit;

the coupling circuit is connected with the second P line input and output port and the second N line input and output port through the lightning stroke protection circuit.

Further, the signal processing module further includes: a common mode filter circuit;

the common mode filter circuit is connected with the second P line input and output port and the second N line input and output port.

Further, the coupling circuit is an ac coupling circuit, the coupling circuit comprising: a first capacitor and a second capacitor;

one end of the first capacitor is connected with the first P line input and output port, and the other end of the first capacitor is connected with the second P line input and output port through the lightning stroke protection circuit;

one end of the second capacitor is connected with the first N-line input and output port, and the other end of the second capacitor is connected with the second N-line input and output port through the lightning stroke protection circuit.

Further, the lightning strike protection circuit is at least one stage.

Further, the lightning strike protection circuit includes: a first stage lightning strike protection circuit, a second stage lightning strike protection circuit; the first stage lightning strike protection circuit includes: the first resistor, the second resistor and the first transient voltage suppression diode; the second-stage lightning strike protection circuit includes: a third resistor, a fourth resistor and a second transient voltage suppression diode;

one end of the first resistor is connected with the first capacitor, and the other end of the first resistor is connected with the second P line input and output port through the third resistor;

one end of the second resistor is connected with the second capacitor, and the other end of the second resistor is connected with the second N-line input and output port through the fourth resistor;

one end of the first transient voltage suppression diode is connected between the second resistor and the fourth resistor, and the other end of the first transient voltage suppression diode is connected between the first resistor and the third resistor;

one end of the second transient voltage suppression diode is connected with the second P line input and output port, and the other end of the second transient voltage suppression diode is connected with the second N line input and output port.

Further, the resistance values of the first resistor, the second resistor, the third resistor and the fourth resistor are greater than or equal to 0.

Further, the common mode filter circuit includes: the first inductor, the second inductor, the fifth resistor, the third capacitor and the fourth capacitor;

one end of the first inductor is connected with the second P line input and output port, and the other end of the first inductor is connected with the second N line input and output port through the second inductor;

one end of the fifth resistor is connected between the first inductor and the second inductor, and the other end of the fifth resistor is grounded through the third capacitor; the fourth capacitor is connected in parallel with the third capacitor.

Further, the high voltage isolation circuit includes: a fifth capacitor, a sixth capacitor, a third inductor and a fourth inductor;

one end of the fifth capacitor is connected with the second P line input and output port, and the other end of the fifth capacitor is connected with the first network port;

one end of the sixth capacitor is connected with the second N-line input and output port, and the other end of the sixth capacitor is connected with the second network port;

one end of the third inductor is connected with the first network port, and the other end of the third inductor is connected with the second network port through the fourth inductor;

and the connecting end of the third inductor and the fourth inductor is connected with the power input of the PoE power supply equipment or the power output of the power receiving equipment.

Further, the coupling circuit is a direct current coupling circuit, and the coupling circuit includes: a sixth resistor and a seventh resistor;

one end of the sixth resistor is connected with the first P line input and output port, and the other end of the sixth resistor is connected with the second P line input and output port through the lightning stroke protection circuit;

one end of the seventh resistor is connected with the first N-line input and output port, and the other end of the seventh resistor is connected with the second N-line input and output port through the lightning stroke protection circuit.

The one or more technical schemes provided by the invention have at least the following beneficial effects or advantages:

according to the PoE equipment without the network transformer, as the chip with the PHY function is connected with the RJ45 connector through the signal processing module and the high-voltage isolation circuit, the communication circuit does not contain the network transformer, only the signal processing module comprises discrete electronic devices, the layout and wiring are flexible, the cost and the board arrangement space are reduced, the miniaturization, the portable design and the user experience of products are facilitated, the PoE equipment with the network transformer can be used in application scenes of some space-limited or modern intelligent buildings, and the popularization and the application of the equipment are facilitated. The high-voltage isolation circuit is used for isolating the low-voltage area from the high-voltage area, and the high-voltage isolation circuit isolates the high voltage of the PoE equipment outside the signal processing circuit and the chip with the PHY function, so that the signal processing circuit in the low-voltage area and the chip with the PHY function are prevented from being broken down by the high voltage.

The PoE equipment without the network transformer provided by the invention does not contain the network transformer, the communication circuit is in butt joint with the existing Ethernet equipment, only one transformer is arranged in a link, the existing resources can be fully utilized, and the data communication and PoE power supply or power receiving with the distance of at least 80m can be realized. Of course, for back-to-back data transmission, devices incorporating the present design may also interface with communications and PoE power or receive power.

The PoE equipment without the network transformer comprises a coupling circuit, a lightning stroke protection circuit and a common mode filter circuit, supports at least differential mode 500V and common mode 1KV lightning stroke surge, and has the overall communication quality not inferior to that of the traditional Ethernet port application circuit with the transformer.

Drawings

Fig. 1 is a schematic diagram of a PoE device without a network transformer on a standard ethernet and a fast ethernet provided in an embodiment of the present invention;

fig. 2 is a schematic diagram of a PoE device without a network transformer on a gigabit ethernet according to an embodiment of the present invention.

Detailed Description

The embodiment of the invention solves the technical problems of high cost, large occupied space and high voltage breakdown of a signal processing circuit in a low-voltage area and a chip with a PHY function caused by the fact that the PoE equipment adopts a network transformer in the prior art by providing the PoE equipment without the network transformer. The PoE equipment without the network transformer is adopted, the cost and the board distribution space are reduced, the popularization and the application of the PoE equipment and other expansion functions are conveniently realized, and a signal processing circuit in a low-voltage area and a chip with PHY (physical layer) function can be prevented from being broken down by high voltage after high-voltage isolation treatment.

The technical scheme of the embodiment of the invention aims to solve the technical problems, and the overall thought is as follows:

referring to fig. 1, an embodiment of the present invention provides a PoE device without network transformer, which includes a chip 1 with PHY function, a signal processing module 2, a high voltage isolation circuit 3, and an RJ45 connector 4. The chip 1 with the PHY function is connected with the high-voltage isolation circuit 3 through the signal processing module 2; the high-voltage isolation circuit 3 is connected with the RJ45 connector 4; the isolation circuit is connected with a power supply of PoE power supply or power receiving equipment, and the RJ45 connector 4 is connected with PD power receiving equipment.

In order to better understand the above technical solutions, the following detailed description will refer to the accompanying drawings and specific embodiments.

Example 1

The present embodiment provides a PoE device without a network transformer, referring to fig. 1, including: a chip 1 with PHY function, a signal processing module 2, a high voltage isolation circuit 3 and an RJ45 connector 4. The chip 1 with PHY function includes P-line ports trd_p and N-line ports trd_n, where a P-line port trd_p and an N-line port trd_n form a data differential line pair, and the number of the data differential line pairs is selected according to the requirement of the connection rate, for example, when the connection rate is 10Mbps, two pairs of data differential line pairs are adopted; when the connection rate is 1000Mbps, four pairs of data differential lines are used. In this embodiment, the connection rate is 10Mbps, and the chip 1 with PHY function includes two sets of differential data line ports, each set of differential data line ports including a P-line port trd_p and an N-line port trd_n. The signal processing module 2 includes a first P-line input and output port si0_p, a first N-line input and output port si0_n, a second P-line input and output port so0_p, and a second N-line input and output port so0_n; the first P-line input and output port si0_p and the first N-line input and output port si0_n constitute a data differential line pair, and the second P-line input and output port so0_p and the second N-line input and output port so0_n constitute a data differential line pair. The RJ45 connector 4 comprises four sets of network ports LAN 1-LAN 8, only 2 pairs of data lines, i.e. LAN1, LAN2, LAN3 and LAN6, are used for standard ethernet (10 Mbit/s) and fast ethernet (100 Mbit/s), in this embodiment one set of differential data line ports corresponds to one set of input and output ports and one set of network ports. The following describes the ethernet port communication circuit without the network transformer by taking a group of differential data line ports, a group of input ports, a group of output ports and a group of network ports as examples:

referring to fig. 1, the signal processing module 2 includes: the lightning protection circuit comprises a coupling circuit, a lightning protection circuit and a common mode filter circuit. Wherein the coupling circuit comprises: the first capacitor C1 and the second capacitor C2 constitute an AC coupling circuit. This embodiment includes two-stage lightning strike protection circuit, and first stage lightning strike protection circuit includes: a first resistor R1, a second resistor R2, and a first transient voltage suppression diode TVS1; the second-stage lightning strike protection circuit includes: the third resistor R3, the fourth resistor R4 and the second TVS2. The common mode filter circuit includes: the first inductor L1, the second inductor L2, the fifth resistor R5, the third capacitor C3 and the fourth capacitor C4. The P-line port trd_p is connected to the first P-line input and output port si0_p, one end of the first capacitor C1 is connected to the first P-line input and output port si0_p, the other end of the first capacitor C1 is connected to the third resistor R3 through the first resistor R1, the third resistor R3 is connected to the second P-line input and output port so0_p, and the second P-line input and output port so0_p is connected to the first network interface LAN1 through the high-voltage isolation capacitor C5. The N-wire port trd_n is connected to the first N-wire input and output port si0_n, one end of the second capacitor C2 is connected to the first N-wire input and output port si0_n, the other end of the second capacitor C2 is connected to the fourth resistor R4 through the second resistor R2, the fourth resistor R4 is connected to the second N-wire input and output port so0_n, and the second N-wire input and output port so0_n is connected to the second network interface LAN2 through the high voltage isolation capacitor C6. One end of the first transient voltage suppression diode TVS1 is connected between the second resistor R2 and the fourth resistor R4, and the other end of the first transient voltage suppression diode TVS1 is connected between the first resistor R1 and the third resistor R3; one end of the second TVS2 is connected to the second P-line input and output port so0_p, and the other end of the second TVS2 is connected to the second N-line input and output port so0_n. One end of the first inductor L1 is connected with the second P line input and output port SO0_P, and the other end of the first inductor L1 is connected with the second N line input and output port SO0_N through the second inductor L2. One end of the fifth resistor R5 is connected between the first inductor L1 and the second inductor L2, and the other end of the fifth resistor R5 is grounded through a third capacitor C3; the fourth capacitor C4 is connected in parallel with the third capacitor C3.

The signal processing module 2 is a circuit formed by discrete electronic devices, taking one pair of differential data in fig. 1 as an example, after the data enter from the first P-line input and output port si0_p and the first N-line input and output port si0_n of the signal processing module 2, the data are AC coupled through the first capacitor C1 and the second capacitor C2, SO as to optimize the output and input signals, eliminate the influence of the level difference of the two devices on the signals, filter the differential mode interference, SO as to realize long-distance signal communication, and output from the second P-line input and output port so0_p and the N-line output end so0_n of the signal processing module 2 to the high-voltage isolation circuit 3. The data after signal processing is directly output through the RJ45 connector 4, is in butt joint with common Ethernet equipment through a network cable, supports data communication of up to 80m, and the whole communication link is only provided with one network transformer on the common Ethernet equipment. Of course, for back-to-back data transmission, devices incorporating the present design may also interface with communications and PoE power or receive power.

Referring to fig. 1, in order to realize the corresponding lightning protection level at the same time, the third resistor R3, the fourth resistor R4 and the second transient voltage suppression diode TVS2 form a first-stage lightning protection, when the lightning high voltage enters from the RJ45 connector 4, the second transient voltage suppression diode TVS2 absorbs the instantaneous high current, clamps the voltages at two ends on the voltage preset by the second transient voltage suppression diode TVS2, and then the third resistor R3 and the fourth resistor R4 limit the current to protect the subsequent-stage circuit. The first resistor R1, the second resistor R2 and the first transient voltage suppression diode TVS1 form second-stage lightning strike protection, the transient voltage suppression diode TVS1 for residual voltage after the first-stage lightning strike protection is limited to a smaller preset voltage, after the current is limited by the first resistor R1 and the second resistor R2, direct-current voltage is isolated through a first capacitor C1 and a second capacitor C2 for AC coupling, and finally the chip 1 with the PHY function is obtained. The first inductor L1 and the second inductor L2 are connected in series between the second P line input and output port SO0_P and the second N line input and output port SO0_N, a fifth resistor R5 is connected at the joint of the first inductor L1 and the second inductor L2, and the fifth resistor R5 is connected with the third capacitor C3 and the fourth capacitor C4 in parallel in series and then connected with the ground GND, SO that common-mode signals can be filtered, and the problems of RE (Radiated Emission, radiation) and CE (Conduction Emission, conduction) can be solved. In the application, the multi-level lightning stroke protection circuit can be added and deleted according to the actual demand, and other protection devices, such as one or more of protection devices of a thermistor, a piezoresistor, a gas discharge tube and the like, are used for preventing differential mode and common mode lightning stroke surges according to different actual application scenes and equipment differences, prevent the lightning stroke from damaging a chip through the PHY port 1, and can support at least differential mode 500V and common mode 1KV lightning stroke surges.

Referring to fig. 1, the high voltage isolation circuit 3 includes: a fifth capacitor C5, a sixth capacitor C6, a third inductor L3 and a fourth inductor L4. One end of a fifth capacitor C5 is connected with the second P line input and output port, and the other end of the fifth capacitor C5 is connected with the first network port LAN 1; the other end of the sixth capacitor C6 is connected to the second N-line input and output port, and the other end of the sixth capacitor C6 is connected to the second network port LAN 2. One end of the third inductor L3 is connected with the first network port LAN1, and the other end of the third inductor L3 is connected with the second network port LAN2 through the fourth inductor L4; the connection end of the third inductor L3 and the fourth inductor L4 is connected with the power input of the PoE power supply equipment or the power output of the power receiving equipment.

Referring to fig. 1, the high voltage isolation circuit 3 is used for carrying out data transmission while loading power supply or receiving voltage, and isolates a low voltage region from a high voltage region, so that the signal processing circuit 2 in the low voltage region and the chip 1 with PHY function are prevented from being broken down by high voltage. The differential signal after signal processing is loaded with the PoE voltage together after passing through the high-voltage isolation circuit 3 and enters the RJ45 connector 4, and an access point between the third inductor L3 and the fourth inductor L4 is used as a PoE power supply access port VCCP. It should be noted that, according to actual needs, an access point between the third inductor L3 and the fourth inductor L4 may also be used as the PoE power access port VCCN. When the power source containing the PoE powered or powered device of the present invention is connected to PoE power access ports VCCP and VCCN, the voltage isolation circuit isolates PoE high voltage from the signal processing circuit 2 and PHY enabled chip 1. For the power supply path, the current passes through the third inductor L3 and the fourth inductor L4 to the first network port LAN1 and the second network port LAN2, and because of the characteristics of direct current and alternating current passing through the third inductor L3 and the fourth inductor L4, the electric potentials on the wires of the first network port LAN1 and the second network port LAN2 are equal and are VCCP, no potential difference exists, and the current does not flow through the high-voltage isolation circuit 3, the signal processing circuit and the chip 1 with PHY function to damage devices, namely, the functions are not affected, and additional power consumption is not generated. So the current on the first network port LAN1 and the second network port LAN2 passes through the RJ45 connector 4, then passes through the network cable to the opposite terminal device and returns to the VCCN, and in the same way, because of the characteristics that the fifth inductor L5 and the sixth inductor L6 are connected with direct current and block alternating current, the electric potentials on the third network port LAN3 and the sixth network port LAN6 are equal, and are all VCCN, no potential difference exists, and the current does not flow through the high voltage isolation circuit 3, the signal processing circuit and the chip 1 with PHY function. For the data communication path, when the signal reaches the junction of the fifth capacitor C5 and the third inductor L3 in the high-voltage isolation circuit 3, the inductor has the characteristics of direct current and alternating current, the capacitor has the characteristics of direct current and direct current, the signal directly enters the fifth capacitor C5 and the sixth capacitor C6, the fifth capacitor C5 and the sixth capacitor C6 filter high voltage, the data enters the signal processing circuit to perform signal optimization processing to the chip 1 with PHY function, or enters the RJ45 connector 4 together with high-voltage loading, and does not enter the third inductor L3 and the fourth inductor L4, so that the data cannot interfere with the power supply or be distorted because the data flows through the inductors to reach the power supply. The data communication and power supply of up to 80m are supported by interfacing with the conventional PoE device via the network cable, and the whole communication link has only 1 PoE network transformer on the conventional PoE device, and also interfacing with the PoE device incorporating the present design. For the requirement of a large-power-consumption load, only the third inductor L3, the fourth inductor L4, the fifth inductor L5 and the sixth inductor L6 with proper rated currents are needed to be selected, so that any large-power equipment access is supported. For data communication at different rates, only the third inductor L3, the fourth inductor L4, the fifth inductor L5 and the sixth inductor L6 with proper inductance values and the fifth capacitor C5, the sixth capacitor C6, the seventh capacitor C7 and the eighth capacitor C8 with proper capacitance values are needed to be selected, so that the purpose that the data signal does not generate distortion or influence the power supply through the third inductor L3, the fourth inductor L4, the fifth inductor L5 and the sixth inductor L6, and meanwhile, the data signal passes through the fifth capacitor C5, the sixth capacitor C6, the seventh capacitor C7 and the eighth capacitor C8 to the maximum extent without distortion is achieved.

Example two

The second embodiment is substantially the same as the PoE device without network transformer provided in the first embodiment, except that: the lightning protection circuit is not contained, and at the moment, the resistor R1 and the resistor R2 can still be arranged in the Ethernet port communication circuit without the network transformer to be matched for use according to the requirement.

Example III

Embodiment three is substantially the same as the PoE device without network transformer provided in embodiment one, except that: the first capacitor C1 in the coupling circuit is replaced by a sixth resistor R6, and the second capacitor C2 is replaced by a seventh resistor R7, constituting the DC coupling circuit.

Example IV

Referring to fig. 2, the fourth embodiment is substantially the same as the PoE device without network transformer provided in the first embodiment, except that: poE devices without network transformers are applied to gigabit ethernet (1000 Mbit/s), using 4 pairs of data lines. Here, the first network port LAN 1/the second network port LAN2, the third network port LAN 3/the sixth network port LAN6 loads VCCP; the fourth network port LAN 4/fifth network port LAN5, the seventh network port LAN 7/eighth network port LAN8 loads the VCCN. It is also possible that the first network port LAN 1/second network port LAN2 loads VCCP (or VCCN), and the third network port LAN 3/sixth network port LAN6 loads VCCN (or VCCP). As shown in fig. 2, the fourth network port LAN 4/fifth network port LAN5 and seventh network port LAN 7/eighth network port LAN8 are not applied with voltage, and the fourth network port LAN 4/fifth network port LAN5 and seventh network port LAN 7/eighth network port LAN8 may not be provided with an inductance; the fourth network port LAN 4/fifth network port LAN5 loads VCCP (or VCCP), the seventh network port LAN 7/eighth network port LAN8 records VCCN (or VCCP), and the first network port LAN 1/second network port LAN2 and the third network port LAN 3/sixth network port LAN6 do not load voltage, that is, the first network port LAN 1/second network port LAN2 and the third network port LAN 3/sixth network port LAN6 may not be provided with inductance.

Referring to fig. 1 and 2, one or more technical solutions provided by the embodiments of the present invention at least have the following beneficial effects or advantages:

according to the network transformer-free PoE equipment provided by the embodiment of the invention, as the chip 1 with the PHY function is connected with the RJ45 connector 4 through the signal processing module 2 and the high-voltage isolation circuit 3, the communication circuit does not contain a network transformer, only the signal processing module 2 comprises discrete electronic devices, the layout and the wiring are flexible, the cost and the board arrangement space are reduced, the product miniaturization, the portable design and the user experience are facilitated, the network transformer-free PoE equipment can be used in application scenes of some space-limited or modern intelligent buildings, and the popularization and the application of the equipment are facilitated. According to the PoE equipment without the network transformer, the high-voltage isolation circuit 3 is used for isolating a low-voltage area from a high-voltage area, and the high-voltage isolation circuit is used for isolating the high voltage of the PoE equipment outside the signal processing circuit and the chip 1 with the PHY function, so that the signal processing circuit in the low-voltage area and the chip 1 with the PHY function are prevented from being broken down by high voltage.

The PoE equipment without the network transformer provided by the embodiment of the invention does not contain the network transformer, the communication circuit is in butt joint with the existing Ethernet equipment, only one transformer is arranged in a link, the existing resource can be fully utilized, the data communication with the distance of at least 80m can be realized, and meanwhile, the long-distance power supply or power receiving is supported. For applications where there is no long-range demand, the ethernet device that may also contain the communication circuit interfaces.

The PoE equipment without the network transformer comprises a coupling circuit, a lightning stroke protection circuit and a common mode filter circuit, supports at least differential mode 500V and common mode 1KV lightning stroke surge, and has overall communication quality not inferior to that of a traditional Ethernet port application circuit with the transformer.

Finally, it should be noted that the above-mentioned embodiments are only for illustrating the technical solution of the present invention, and not for limiting the same, and although the present invention has been described in detail with reference to examples, it should be understood by those skilled in the art that modifications and equivalents may be made to the technical solution of the present invention without departing from the spirit and scope of the technical solution of the present invention, and all such modifications and equivalents are intended to be encompassed in the scope of the claims of the present invention.

Claims

1. The PoE equipment without the network transformer is characterized by comprising a chip with PHY (physical layer) functions, a signal processing module, a high-voltage isolation circuit and an RJ45 connector;

the chip with the PHY function is connected with the high-voltage isolation circuit through the signal processing module; the high-voltage isolation circuit is connected with the RJ45 connector; the high-voltage isolation circuit is connected with the power input of PoE power supply equipment or the power output of powered equipment, and the RJ45 connector is connected with the PoE power supply or powered equipment

The signal processing module includes: a coupling circuit;

the RJ45 connector comprises a first network port and a second network port;

the P line port is connected with the first P line input and output port, and the first P line input and output port is connected with the coupling circuit; the coupling circuit is connected with the second P line input and output port; the second P line input and output port is connected with the first network port through the high-voltage isolation circuit;

the N-line port is connected with the first N-line input and output port, and the first N-line input and output port is connected with the coupling circuit; the coupling circuit is connected with the second N-line input and output port; the second N-line input and output port is connected with the second network port through the high-voltage isolation circuit;

the high voltage isolation circuit includes: a fifth capacitor, a sixth capacitor, a third inductor and a fourth inductor;

2. The network transformer less PoE device of claim 1, wherein said signal processing module further comprises: a lightning strike protection circuit;

3. The network transformer less PoE device of claim 1, wherein said signal processing module further comprises: a common mode filter circuit;

4. A network transformer less PoE device as recited in claim 2 wherein said coupling circuit is an ac coupling circuit, said coupling circuit comprising: a first capacitor and a second capacitor;

5. The network transformer less PoE device of claim 4, wherein said lightning strike protection circuit comprises: a first-stage lightning strike protection circuit and a second-stage lightning strike protection circuit; the first stage lightning strike protection circuit includes: the first resistor, the second resistor and the first transient voltage suppression diode; the second-stage lightning strike protection circuit includes: a third resistor, a fourth resistor and a second transient voltage suppression diode;

6. The network transformer less PoE device of claim 5, wherein said first, second, third and fourth resistors have values greater than or equal to 0.

7. A network transformer less PoE device as recited in claim 3 wherein said common mode filter circuit comprises: the first inductor, the second inductor, the fifth resistor, the third capacitor and the fourth capacitor;

8. A network transformer less PoE device as recited in claim 2 wherein said coupling circuit is a dc coupling circuit, said coupling circuit comprising: a sixth resistor and a seventh resistor;