Power supply device, power receiving device, and power over Ethernet system

Abstract

The invention provides power supply equipment, power receiving equipment and an Ethernet power supply system, and belongs to the technical field of Ethernet power supply. In the scheme provided by the invention, the positive electrode of the direct-current power supply end in the power supply equipment and the positive electrode of the direct-current power supply end in the power receiving equipment are connected with the center tap of the transformer, the negative electrode of the direct-current power supply end is connected with the shielding layer of the shielding differential line, and the two signal lines in the shielding differential line are connected with the two ends of the transformer. Based on the connection mode, the two signal lines in the shielding differential line can be connected in parallel, so that the direct-current resistance of the shielding differential line is effectively reduced. Therefore, the power loss and the voltage loss of the shielding differential line can be effectively reduced.

Description

Technical Field

[0001] The present application relates to the technical field of Ethernet power supply, and in particular to a power supply device, a powered device and an Ethernet power supply system. Background Art

[0002] Single pair Ethernet (SPE) is a technology that uses a single twisted pair of cables to transmit Ethernet data. SPE also allows power sourcing equipment (PSE) to power its connected powered device (PD) via power over data line (PoDL).

[0003] In the PoDL system (also called a single-pair Ethernet power supply system), the positive electrode of the PSE chip in the power supply device is connected to the positive end of the twisted pair, and the negative electrode of the PSE chip is connected to the negative end of the twisted pair. The positive electrode of the PD chip in the powered device is connected to the positive end of the twisted pair, and the negative electrode of the PD chip is connected to the negative end of the twisted pair.

[0004] Based on the above connection relationship, the positive phase end and the negative phase end of the twisted pair are in a series relationship, which will lead to a larger DC resistance of the twisted pair, thereby causing a larger power loss and voltage loss. Summary of the invention

[0005] The present application provides a power supply device, a powered device and an Ethernet power supply system, which can solve the technical problem of large power loss and voltage loss in the PoDL system in the related art.

[0006] In a first aspect, a power supply device is provided, which is applied to an Ethernet power supply system. The Ethernet power supply system also includes a powered device, and the power supply device is connected to the powered device through a shielded differential line. The power supply device includes: a power supply chip and a transformer. The positive pole of the power supply end of the power supply chip is connected to the center tap of the first side of the transformer, and the negative pole of the power supply end of the power supply chip is connected to the shielding layer of the shielded differential line. One end of the first side of the transformer is connected to the first signal line in the shielded differential line, and the other end of the first side of the transformer is connected to the second signal line in the shielded differential line. The first side of the transformer is one of the primary side and the secondary side.

[0007] Based on the above connection method of the shielded differential line, the two signal lines in the shielded differential line can be connected in parallel, thereby effectively reducing the DC resistance of the shielded differential line, and further effectively reducing the power loss and voltage loss of the shielded differential line.

[0008] Optionally, the power supply device may further include: a physical layer chip, wherein the physical layer chip is connected to the second side of the transformer, and the second side of the transformer may be the other of the primary side and the secondary side.

[0009] It is understandable that the physical layer chip can be used to exchange data signals with the physical layer chip in the powered device through the shielded differential line. The transformer can be used to achieve signal coupling between two physical layer chips and can be used to extend the transmission distance of the signal.

[0010] Optionally, the first side of the transformer can be directly connected to the shielded differential line, that is, no capacitor needs to be provided between the first side of the transformer and the shielded differential line, thereby effectively simplifying the structure of the power supply device and reducing the cost of the power supply device.

[0011] For example, one end of the first side of the transformer may be directly connected to the first signal line in the shielded differential line through a wire, and the other end of the first side of the transformer may be directly connected to the second signal line in the shielded differential line through a wire.

[0012] Optionally, the positive electrode of the power supply end of the power supply chip is directly connected to the center tap of the first side of the transformer. That is, no inductance is required between the positive electrode of the power supply end of the power supply chip and the transformer, thereby effectively simplifying the structure of the power supply device and reducing the cost of the power supply device.

[0013] Optionally, the negative electrode of the power supply terminal of the power supply chip is directly connected to the shielding layer of the shielded differential line. That is, no inductance is required between the negative electrode of the power supply terminal of the power supply chip and the shielded differential line, thereby effectively simplifying the structure of the power supply device and reducing the cost of the power supply device.

[0014] For example, the positive electrode of the power supply end of the power supply chip and the transformer can be directly connected through a wire, and the negative electrode of the power supply end of the power supply chip and the shielded differential line can also be directly connected through a wire.

[0015] In the second aspect, a powered device is provided, which is applied to an Ethernet power supply system. The Ethernet power supply system also includes a power supply device, and the powered device is connected to the power supply device through a shielded differential line. The powered device includes: a powered chip and a transformer; the positive pole of the powered end of the powered chip is connected to the center tap of the first side of the transformer, and the negative pole of the powered end of the powered chip is connected to the shielding layer of the shielded differential line. One end of the first side of the transformer is connected to the first signal line in the shielded differential line, and the other end of the first side of the transformer is connected to the second signal line in the shielded differential line. The first side of the transformer is one of the primary side and the secondary side.

[0016] Based on the above connection method of the shielded differential line, the two signal lines in the shielded differential line can be connected in parallel, thereby effectively reducing the DC resistance of the shielded differential line, and further effectively reducing the power loss and voltage loss of the shielded differential line.

[0017] Optionally, the powered device may further include: a physical layer chip, wherein the physical layer chip is connected to the second side of the transformer, and the second side of the transformer may be the other of the primary side and the secondary side.

[0018] It can be understood that the first side of the transformer in the power receiving device and the first side of the transformer in the power supply device can be of the same type, that is, both are secondary sides, or both are primary sides. Correspondingly, the second side of the transformer in the power receiving device and the second side of the transformer in the power supply device are of the same type, that is, both are primary sides, or both are secondary sides.

[0019] Optionally, the first side of the transformer can be directly connected to the shielded differential line, that is, no capacitor needs to be provided between the first side of the transformer and the shielded differential line, thereby effectively simplifying the structure of the powered device and reducing the cost of the powered device.

[0020] Optionally, the positive electrode of the power receiving terminal of the power receiving chip is directly connected to the center tap of the first side of the transformer. That is, no inductance needs to be arranged between the positive electrode of the power receiving terminal of the power receiving chip and the transformer, thereby effectively simplifying the structure of the power receiving device and reducing the cost of the power receiving device.

[0021] Optionally, the negative electrode of the power receiving terminal of the power receiving chip is directly connected to the shielding layer of the shielded differential line. That is, no inductance is required between the negative electrode of the power receiving terminal of the power receiving chip and the shielded differential line, thereby effectively simplifying the structure of the power receiving device and reducing the cost of the power receiving device.

[0022] For example, the positive electrode of the power receiving end of the power receiving chip and the transformer can be directly connected through a wire, and the negative electrode of the power receiving end of the power receiving chip and the shielded differential line can also be directly connected through a wire.

[0023] In a third aspect, an Ethernet power supply system is provided, the Ethernet power supply system comprising: a power supply device as provided in the first aspect, a powered device as provided in the second aspect, and a shielded differential line, wherein the power supply device and the powered device can be connected via the shielded differential line.

[0024] It is understandable that the power supply device can supply power to the powered device through the shielded differential line, and can exchange data with the powered device through the shielded differential line. In addition, the Ethernet power supply system can be applied to various power supply scenarios such as campus fire monitoring, building automation, industrial control or vehicle-mounted.

[0025] It can also be understood that the Ethernet power supply system can be a point-to-point power supply system using single-pair Ethernet technology, that is, a power supply device in the Ethernet power supply system can be connected to a powered device through a pair of shielded differential lines and supply power to the powered device.

[0026] Optionally, the shielded differential line may be a twisted pair, a parallel line or a power line. Furthermore, the material of the shielding layer in the shielded differential line is a metal material, and the metal material may include aluminum and / or copper.

[0027] In summary, the present application provides a power supply device, a powered device, and an Ethernet power supply system. In the solution provided by the present application, the positive pole of the DC power supply terminal in the power supply device and the powered device is connected to the center tap of the transformer, the negative pole of the DC power supply terminal is connected to the shielding layer of the shielded differential line, and the two signal lines in the shielded differential line are connected to the two ends of the transformer. Based on the above connection method, the two signal lines in the shielded differential line can be connected in parallel, thereby effectively reducing the DC resistance of the shielded differential line. In this way, the power loss and voltage loss of the shielded differential line can be effectively reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a structural schematic diagram of an Ethernet power supply system in the related art;

[0029] Figure 2 yes Figure 1 A schematic diagram of a DC power supply signal and a valid data signal in the system shown;

[0030] Figure 3 It is a structural schematic diagram of an Ethernet power supply system provided in an embodiment of the present application;

[0031] Figure 4 It is a structural schematic diagram of a shielded differential line provided in an embodiment of the present application;

[0032] Figure 5 is a schematic diagram of the structure of another shielded differential line provided in an embodiment of the present application;

[0033] Figure 6 It is a schematic diagram of current flow in an Ethernet power supply system provided in an embodiment of the present application. DETAILED DESCRIPTION

[0034] The power supply device, powered device and Ethernet power supply system provided by the embodiments of the present application are described in detail below with reference to the accompanying drawings.

[0035] In order to make the technical solutions provided by the embodiments of the present application clearer, relevant terms are first explained before the technical solutions provided by the embodiments of the present application are described in detail.

[0036] 1. Common mode signal (CMS), also known as ground induced signal or asymmetric signal, refers to the noise of two signal lines to the ground, which are equal in size and have a phase difference of 0.

[0037] 2. Differential mode signal (DMS), also known as normal mode, series mode, line induction or symmetrical signal, refers to the signal difference between two signal lines, which are equal in size and have a phase difference of 180°.

[0038] 3. Positive signal: a positive signal in a pair of differential signals. Correspondingly, a positive (P) terminal may refer to a signal line in a pair of differential lines (eg, twisted pair) that carries a positive signal.

[0039] 4. Negative signal: the negative signal in a pair of differential signals. Correspondingly, the negative (N) end can be a signal line in a pair of differential lines (such as twisted pair) that carries the negative signal.

[0040] 5. Shielded twisted-pair cable (STP) is a copper twisted-pair cable widely used for data transmission. In terms of physical structure, shielded twisted-pair cable has an additional shielding layer than unshielded twisted-pair cable. Shielding can reduce noise and provide a cleaner channel.

[0041] The single-pair Ethernet technology currently used in industrial scenarios can realize the Internet protocol (IP) of the fieldbus and can also power equipment through a single pair of twisted pairs. Typical standards include: Institute of Electrical and Electronics Engineers (IEEE) 802.3cg, IEEE802.3bu, etc.

[0042] As an alternative to Power over Ethernet (PoE) in industrial communications, PoDL allows long-distance communication and power supply between PSE and PD, and can achieve power supply at a maximum distance of 1000 meters. Figure 1 ,PoDL consists of two main parts PSE and PD, which are connected through a single twisted pair ,cable.

[0043] like Figure 2As shown, the DC power supply signal (indicated by the dotted line) is a differential signal for the valid data signal (indicated by the solid line). The 12V in the DC power supply signal can be coupled with the P signal in the twisted pair, and the ground (GND) in the DC power supply signal is coupled with the N signal. It can be understood that Figure 2 V1 represents the voltage of the P signal, V2 represents the voltage of the N signal, and V DIFF Indicates the difference between the P signal and the N signal.

[0044] In order not to affect signal transmission, the coupling / decoupling of DC power supply signal and valid data signal is realized, such as Figure 1 As shown, additional capacitors and inductors need to be added to the PoDL system. Figure 1 , inductors L1 and L2, and capacitors C1 and C2 are added to the PSE. The PSE chip is connected to one end of the twisted pair through inductors L1 and L2, and the transformer is connected to one end of the twisted pair through capacitors C1 and C2. Inductors L3 and L4, and capacitors C3 and C4 are added to the PD. The PD chip is connected to the other end of the twisted pair through inductors L3 and L4, and the transformer is connected to the other end of the twisted pair through capacitors C3 and C4. The above-mentioned additional 4 capacitors and 4 inductors will result in higher cost and structural complexity of the PoDL system.

[0045] And, from Figure 1 As shown in the figure, the P-end and N-end of the twisted pair (i.e., the two signal lines in the twisted pair) are in series. Therefore, the DC resistance of the twisted pair is large, which will cause large transmission losses and energy waste, and will also bring unnecessary voltage drops. It is understandable that when the voltage drops seriously, the input voltage of the PD end will not meet the working requirements of the receiving end, which will cause the system or key nodes to fail to work properly.

[0046] Referring to Table 1, taking a typical AWG18 cable as an example, its DC resistance of 1 km is 21.4 ohms. It can also be seen from Table 1 that the outer diameter of the AWG18 cable is 1.02 millimeters (mm), that is, 0.0403 inches (inch), and the cross-sectional area is 0.8107 square millimeters (mm 2 ).

[0047] Table 1

[0048] AWG Outer diameter(mm) Outer diameter(inch) <![CDATA[Cross-sectional area (mm 2 )]]> Resistance value (Ω / km) 18 1.02 0.0403 0.8107 21.4

[0049] Figure 1The PoDL system shown uses AWG18 cables, and the corresponding cable loss and cable voltage drop at each power level (class) can be shown in Table 2. VCC in Table 2 represents the gear of the DC voltage output by the PSE, and class0 to class9 can represent 10 different power levels. Vpsemax represents the maximum voltage output by the PSE, in volts (V); Ppsemax represents the maximum power output by the PSE, in watts (W); Imax represents the maximum current output by the PSE, in milliamperes (mA). deltaP represents the power loss per kilometer of the AWG18 cable, in W; deltaU represents the voltage loss per kilometer of the AWG18 cable, in V; Vpd represents the voltage that the PD can obtain at different power levels, in V; Vpdmin represents the minimum input voltage at which the PD can work normally at different power levels, in V. It can be understood that since the maximum power and maximum current output by the PSE are different at different power levels, the minimum input voltage at which the PD can work normally at different power levels is also different.

[0050] Referring to Table 2, we can see that Figure 1 When the PoDL system shown adopts class 3 and class 9 solutions, the PD will not work properly because the voltage available to the PD is lower than the minimum input voltage when the PD works normally.

[0051] Table 2

[0052]

[0053]

[0054] The present application provides an Ethernet power supply system that can solve the problem that the DC resistance of the twisted pair is too large, resulting in large cable power loss and voltage loss. Figure 3 As shown, the Ethernet power supply system includes: a power supply device 10, a powered device 20, and a pair of shielded differential lines 30. The power supply device 10 and the powered device 20 are connected via the shielded differential line 30.

[0055] Figure 4 Schematic diagram of a shielded differential line structure provided by an embodiment of the present application. Figure 3 and Figure 4 As shown, the shielded differential line 30 may include a first signal line 301, a second signal line 302 and a shielding layer 303. The shielding layer 303 may be made of a metal material, which may include copper and / or aluminum foil.

[0056] Optionally, the shielding layer 303 may also include a metal braid, and the material of the metal braid may be aluminum. Figure 4 The shielded differential line 30 may further include a sheath 304. In the embodiment of the present application, the shielded differential line 30 may be a twisted pair (ie, a shielded twisted pair), a parallel line, or a power line.

[0057] It can be understood that the Ethernet power supply system provided in the embodiment of the present application can be a point-to-point DC power supply system, that is, a power supply device 10 in the system is connected to a powered device 20 through a pair of shielded differential lines 30 and supplies power to the powered device 20.

[0058] It can also be understood that the Ethernet power supply system provided in the embodiment of the present application can be a power supply system using single-pair Ethernet technology, such as a PoDL power supply system. In addition, the system can be applied to scenarios such as campus fire monitoring, building automation, industrial control, or vehicle-mounted power supply using single-pair Ethernet technology.

[0059] Optionally, the power supply device 10 in the Ethernet power supply system can be a network switch, an industrial network management or a vehicle gateway, etc. The powered device 20 can be an industrial instrument, an alarm or a sensor (such as a vehicle radar), etc.

[0060] The following article introduces the power supply device and the powered device in the Ethernet power supply system.

[0061] like Figure 3 As shown, the power supply device 10 in the Ethernet power supply system includes: a power supply chip 101 and a transformer 102. The power supply chip 101 can also be called a PSE chip. The positive electrode VCC of the power supply end of the power supply chip 101 is connected to the center tap of the first side of the transformer 102, and the negative electrode of the power supply end of the power supply chip 101 is connected to the shielding layer 303 of the shielded differential line 30. One end of the first side of the transformer 102 is connected to the first signal line 301 in the shielded differential line 30, and the other end of the first side of the transformer 102 is connected to the second signal line 302 in the shielded differential line 30.

[0062] The first side of the transformer 102 may be one of a primary side and a secondary side, for example, a primary side. Figure 3 The power supply end of the power supply chip 101 may also be called a DC power supply end, and the negative electrode of the power supply end may be a ground end GND.

[0063] Continue to refer Figure 1The powered device 20 in the Ethernet power supply system includes: a powered chip 201 and a transformer 202. The powered chip 201 can also be called a PD chip. The positive electrode VCC of the powered end of the powered chip 201 is connected to the center tap of the first side of the transformer 202, and the negative electrode (i.e., the ground terminal GND) of the powered end of the powered chip 201 is connected to the shielding layer 303 of the shielded differential line 30. One end of the first side of the transformer 202 is connected to the first signal line 301 in the shielded differential line 30, and the other end of the first side of the transformer 202 is connected to the second signal line 302 in the shielded differential line 30.

[0064] The first side of the transformer 202 may be one of a primary side and a secondary side. Furthermore, the first side of the transformer 202 may be of the same type as the first side of the transformer 102, that is, both are primary sides or both are secondary sides. Figure 3 The power receiving end of the power receiving chip 201 may also be called a DC power supply end, and the negative electrode of the power receiving end may be a ground end GND.

[0065] Based on the above connection method, we can know that Figure 5 The solution provided in the embodiment of the present application can combine the P end and the N end (i.e., the first signal line 301 and the second signal line 302) in the shielded differential line 30, and use them as the positive electrode VCC of the DC voltage, and use the shielding layer 303 in the shielded differential line 30 as the return GND of the DC voltage. In this way, the two signal lines in the shielded differential line can be changed from the original series relationship to a parallel relationship, thereby effectively reducing the power loss and voltage loss of the shielded differential line 30.

[0066] In summary, an embodiment of the present application provides a power supply device, in which the positive pole of the power supply end of the power supply chip is connected to the center tap of the first side of the transformer, and the negative pole of the power supply end is connected to the shielding layer of the shielded differential line. In addition, the two ends of the first side of the transformer are respectively connected to the two signal lines in the shielded differential line. Based on the above connection method, the two signal lines in the shielded differential line can be connected in parallel, thereby effectively reducing the power loss and voltage loss of the shielded differential line.

[0067] The embodiment of the present application also provides a power receiving device, in which the positive pole of the power receiving end of the power receiving chip is connected to the center tap of the transformer, and the negative pole of the power receiving end is connected to the shielding layer of the shielded differential line. In addition, the two ends of the first side of the transformer are respectively connected to the two signal lines in the shielded differential line. Based on the above connection method, the two signal lines in the shielded differential line can be connected in parallel, thereby effectively reducing the power loss and voltage loss of the shielded differential line.

[0068] Figure 6Schematic diagram of current flow in an Ethernet power supply system provided by an embodiment of the present application. Figure 1 and Figure 6 It can be seen that the change in the underlying connection relationship in the solution provided in the embodiment of the present application can change the P end and the N end of the shielded differential line 30 (i.e., the first signal line 301 and the second signal line 302) from the original series relationship to a parallel relationship. Thus, the power loss and voltage loss of the shielded differential line can be effectively reduced.

[0069] For example, assume that the equivalent DC resistance of the P end (e.g., the first signal line 301) of the shielded differential line 30 is Rp, and the equivalent DC resistance of the N end (e.g., the second signal line 302) is Rn. Since the P end and the N end are differential lines, it can be considered that the equivalent resistances of the two are approximately equal, that is, Rp≈Rn. Since the shielding layer 303 of the shielded differential line 30 is a metal plane (e.g., a copper plane), the equivalent DC resistance of the shielding layer 303 can be ignored.

[0070] If the power loss of the shielded differential line is △P, the voltage loss is △U, and the current passing through is I. Then, Figure 1 In the scheme shown, the equivalent DC resistance R of the shielded differential line can satisfy: R=Rp+Rn=2Rp, the voltage loss △U can be: △U=2Rp×I, and the power loss △P can be: △P=2Rp×I×I.

[0071] Correspondingly, the equivalent resistance R of the shielded differential line 30 in the embodiment of the present application can satisfy: R=Rp / / Rn=Rp / 2, the voltage loss △U can be: △U=Rp / 2×I, and the power loss △P can be: △P=Rp / 2×I×I.

[0072] Based on the above analysis, it can be seen that the solution provided by the embodiment of the present application can change the series relationship of the two signal lines in the shielded differential line into a parallel relationship, thereby reducing the power loss of the cable to 25% of the original, and reducing the voltage loss of the cable to 25% of the original. In other words, the solution provided by the embodiment of the present application effectively reduces the power loss and voltage loss of the cable.

[0073] The cable loss and cable voltage drop corresponding to each power level of the solution provided in the embodiment of the present application can be shown in Table 3. Comparing Table 2 and Table 3, it can be seen that when the solution provided in the embodiment of the present application adopts the class 3 and class 9 solutions, the voltage available to the PD is greater than the minimum input voltage when the PD works normally, so the PD can work normally.

[0074] Table 3

[0075]

[0076]

[0077] Alternatively, if Figure 3 As shown, the power supply device 10 may further include a physical layer (PHY) chip 103, which is connected to the second side of the transformer 102. It is understandable that the second side of the transformer 102 may be the other of the primary side and the secondary side, for example, the secondary side.

[0078] Optionally, continue to refer to Figure 3 The powered device 20 may further include a physical layer chip 203, and the physical layer chip 203 is connected to the second side of the transformer 202. It is understood that the second side of the transformer 202 may be the other of the primary side and the secondary side. Furthermore, the second side of the transformer 202 may be of the same type as the second side of the transformer 102, that is, both are secondary sides, or both are primary sides.

[0079] It can also be understood that the physical layer chip 103 in the power supply device 10 can be used to exchange data signals with the physical layer chip 203 in the powered device 20 through the shielded differential line 30. The transformer 102 and the transformer 202 can be used to achieve signal coupling between the two physical layer chips, and can be used to extend the transmission distance of the signal.

[0080] Alternatively, if Figure 3 As shown, the first side of the transformer 102 in the power supply device 10 can be directly connected to the shielded differential line 30. That is, no capacitor is required between the first side of the transformer 102 and the shielded differential line 30, thereby effectively simplifying the structure of the power supply device 10 and reducing the cost of the power supply device 10.

[0081] For example, one end of the first side of the transformer 102 may be directly connected to the first signal line 301 in the shielded differential line 30 through a wire, and the other end of the first side of the transformer 102 may be directly connected to the second signal line 302 in the shielded differential line 30 through a wire.

[0082] Continue to refer Figure 3 , the first side of the transformer 202 in the powered device 20 can be directly connected to the shielded differential line 30. That is, no capacitor is required between the first side of the transformer 202 and the shielded differential line 30, thereby effectively simplifying the structure of the powered device 20 and reducing the cost of the powered device 20.

[0083] For example, one end of the first side of the transformer 202 may be directly connected to the first signal line 301 in the shielded differential line 30 through a wire, and the other end of the first side of the transformer 202 may be directly connected to the second signal line 302 in the shielded differential line 30 through a wire.

[0084] Alternatively, if Figure 3 As shown, the positive electrode of the power supply end of the power supply chip 101 is directly connected to the center tap of the first side of the transformer 102. In addition, the negative electrode of the power supply end of the power supply chip 101 can also be directly connected to the shielding layer 303 of the shielded differential line 30. That is, no inductance is required between the power supply chip 101 and the transformer 102, and between the power supply chip 101 and the shielded differential line 30, thereby effectively simplifying the structure of the power supply device 10 and reducing the cost of the power supply device 10.

[0085] For example, the positive electrode of the power supply end of the power supply chip 101 can be directly connected to the transformer 102 through a wire, and the negative electrode of the power supply end of the power supply chip 101 can also be directly connected to the shielding differential line 30 through a wire.

[0086] Continue to refer Figure 3 , the positive electrode of the power receiving end of the power receiving chip 201 can also be directly connected to the center tap of the first side of the transformer 202. In addition, the negative electrode of the power receiving end of the power receiving chip 201 can also be directly connected to the shielding layer 303 of the shielded differential line 30. That is, no inductance is required between the power receiving chip 201 and the transformer 202, and between the power receiving chip 201 and the shielded differential line 30, thereby effectively simplifying the structure of the power receiving device 20 and reducing the cost of the power receiving device 20.

[0087] For example, the positive electrode of the power receiving end of the power receiving chip 201 can be directly connected to the transformer 202 through a wire, and the negative electrode of the power receiving end of the power receiving chip 201 can also be directly connected to the shielded differential line 30 through a wire.

[0088] In traditional schemes, Figure 1 and Figure 2 As shown, VCC is coupled to the P end of the twisted pair, and GND is coupled to the N end of the twisted pair, so the DC power supply signal is a differential signal relative to the data signal. In the embodiment of the present application, the positive electrode VCC (such as 12V) of the power supply end of the power supply chip 101 is directly coupled to the center tap of the transformer, and the shielding layer 303 in the shielded differential line 30 is used as the return ground (GND). At this time, the DC power supply VCC (such as 12V) is a common mode signal relative to the P signal and the N signal in the differential signal. Therefore, in the solution provided in the embodiment of the present application, there is no need to set 4 capacitors and 4 inductors used for coupling / decoupling in the power supply device 10 and the powered device 20, thereby effectively simplifying the circuit complexity and reducing the material cost.

[0089] It is understandable that an inductor may be provided between the positive electrode of the power supply end of the power supply chip 101 and the center tap of the transformer 102. Furthermore, an inductor may be provided between the negative electrode of the power supply end of the power supply chip 101 and the shielding layer 303 of the shielding differential line 30. The embodiment of the present application does not limit this.

[0090] Similarly, an inductor may be provided between the positive electrode of the power receiving end of the power receiving chip 201 and the center tap of the transformer 202. In addition, an inductor may also be provided between the negative electrode of the power receiving end of the power receiving chip 201 and the shielding layer 303 of the shielding differential line 30. This embodiment of the present application does not limit this.

[0091] In summary, the embodiments of the present application provide a power supply device, a powered device, and an Ethernet power supply system. In the solution provided by the embodiments of the present application, the positive pole of the DC power supply terminal in the power supply device and the powered device is connected to the center tap of the transformer, the negative pole of the DC power supply terminal is connected to the shielding layer of the shielded differential line, and the two signal lines in the shielded differential line are connected to the two ends of the transformer. Based on the above connection method, the two signal lines in the shielded differential line can be connected in parallel, thereby effectively reducing the DC resistance of the shielded differential line. As a result, the power loss and voltage loss of the shielded differential line can be effectively reduced.

[0092] Moreover, based on the above connection mode, the mathematical relationship between the DC power supply signal and the valid data signal can also be changed from a differential mode relationship to a common mode relationship. Thus, the coupling / decoupling structure of power supply and communication can be simplified, thereby effectively reducing the cost and structural complexity of the Ethernet power supply system. For example, the solution provided in the embodiment of the present application can save 4 capacitors and 4 inductors.

[0093] It can be understood that the solution provided by the embodiment of the present application is not limited by the transmission mechanism, propagation medium and usage scenario of the effective data signal. As long as there is a differential cable with a shielding layer, the solution provided by the embodiment of the present application can be adopted. Among them, the transmission mechanism of the effective data signal may include single-carrier pulse amplitude modulation (PAM), discrete multitone (DMT) modulation or orthogonal frequency division multiplexing (OFDM), etc. The differential transmission medium with a shielding layer may be a twisted pair, parallel lines or power lines, etc. The usage scenario may be a campus scene, an industrial scene or a vehicle-mounted scene, etc.

[0094] In the embodiments of the present application, the terms "first", "second" and "third" are used for descriptive purposes only and should not be understood as indicating or implying relative importance. The term "at least one" means one or more, and "plurality" means two or more.

[0095] The term "and / or" in this application is only a description of the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0096] The above is only an optional implementation of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can easily think of various equivalent modifications or replacements within the technical scope disclosed in the present application, and these modifications or replacements should be included in the protection scope of the present application. Therefore, the protection scope of the present application shall be based on the protection scope of the claims.

Claims

1. A power supply device, characterized in that: Applied to an Ethernet power supply system, the Ethernet power supply system also includes a powered device, the power supply device is connected to the powered device via a shielded differential line; the power supply device includes: a power supply chip and a transformer; The positive electrode of the power supply end of the power supply chip is connected to the center tap of the first side of the transformer, and the negative electrode of the power supply end of the power supply chip is connected to the shielding layer of the shielded differential line; One end of the first side of the transformer is connected to the first signal line in the shielded differential line, and the other end of the first side of the transformer is connected to the second signal line in the shielded differential line; The first side of the transformer is one of a primary side and a secondary side.

2. The power supply device according to claim 1, characterized in that: The power supply device further includes: a physical layer chip, wherein the physical layer chip is connected to the second side of the transformer, and the second side of the transformer is the other of the primary side and the secondary side.

3. The power supply device according to claim 1 or 2, characterized in that: The first side of the transformer is directly connected to the shielded differential line.

4. The power supply device according to any one of claims 1 to 3, characterized in that: The positive pole of the power supply end of the power supply chip is directly connected to the center tap of the first side of the transformer.

5. The power supply device according to any one of claims 1 to 4, characterized in that: The negative electrode of the power supply terminal of the power supply chip is directly connected to the shielding layer of the shielded differential line.

6. A power receiving device, characterized in that: Applied to an Ethernet power supply system, the Ethernet power supply system also includes a power supply device, the powered device is connected to the power supply device via a shielded differential line; the powered device includes: a powered chip and a transformer; The positive electrode of the power receiving end of the power receiving chip is connected to the center tap of the first side of the transformer, and the negative electrode of the power receiving end of the power receiving chip is connected to the shielding layer of the shielded differential line; One end of the first side of the transformer is connected to the first signal line in the shielded differential line, and the other end of the first side of the transformer is connected to the second signal line in the shielded differential line; The first side of the transformer is one of a primary side and a secondary side.

7. The power receiving device according to claim 6, characterized in that: The powered device further includes: a physical layer chip, wherein the physical layer chip is connected to a second side of the transformer, and the second side of the transformer is the other of the primary side and the secondary side.

8. The power receiving device according to claim 6 or 7, characterized in that: The first side of the transformer is directly connected to the shielded differential line.

9. The power receiving device according to any one of claims 6 to 8, characterized in that: The positive electrode of the power receiving end of the power receiving chip is directly connected to the center tap of the first side of the transformer.

10. The power receiving device according to any one of claims 6 to 9, characterized in that: The negative electrode of the power receiving terminal of the power receiving chip is directly connected to the shielding layer of the shielded differential line.

11. An Ethernet power supply system, characterized in that: The Ethernet power supply system comprises: the power supply device according to any one of claims 1 to 5, the powered device according to any one of claims 6 to 10, and a shielded differential line; Wherein, the power supply device and the powered device are connected via the shielded differential line.

12. The system according to claim 11, characterized in that The shielded differential line is a twisted pair, parallel lines or power lines.

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