POE power supply circuit and power supply system

Abstract

The invention relates to a POE power supply circuit and a power supply system, the POE power supply circuit comprises a network transmission circuit, a rectifier bridge, a step-down circuit and a handshake protocol circuit, the rectifier bridge is provided with two rectifier chips, one end of one rectifier chip is connected with the network transmission circuit, one end of the other rectifier chip is connected with a POE power supply, and the other end of the other rectifier chip is connected with the handshake protocol circuit. The other ends of the two rectification chips are connected with the handshake protocol circuit, and the step-down circuit is connected with the handshake protocol circuit and a power supply output end. According to the POE power supply circuit, the rectifier bridge is provided with the two rectifier chips, the element layout on the PCB is optimized through the rectifier bridge, the step-down circuit and the handshake protocol circuit, the number of elements is reduced, the occupied PCB space is reduced, the production cost is further reduced, and the economic benefits are improved.

Description

Technical Field

[0001] The present application relates to the field of power supply technology, and in particular to a POE power supply circuit and a power supply system. Background Art

[0002] POE (Power Over Ethernet) refers to a technology that, without any changes to the existing Ethernet Cat.5 cabling infrastructure, can simultaneously transmit data signals to IP-based terminals (such as IP phones, wireless LAN access points (APs), and network cameras) while also providing DC power to these devices. POE technology ensures the security of existing structured cabling while ensuring the normal operation of existing networks and minimizing costs. A complete POE system consists of two parts: the power sourcing equipment (PSE) and the powered device (PD). The PSE provides power to Ethernet client devices and manages the entire POE power supply process. The PD is the load that receives power from the PSE and is the client device of the POE system.

[0003] In the prior art, the POE power supply circuit of the network camera has many components, which takes up a large space on the PCB board, is not conducive to product miniaturization design and optimization of PCB board component layout, and is costly. Summary of the Invention

[0004] The purpose of this application is to provide a POE power supply circuit and power supply system to solve the problem that the existing POE power supply circuit occupies a large space on the PCB board, which is not conducive to product miniaturization and component layout.

[0005] In order to solve the above problems, this application adopts the following technical solutions: The first aspect of the present application provides a POE power supply circuit, which includes: a network transmission circuit, a rectifier bridge, a step-down circuit and a handshake protocol circuit. The rectifier bridge is provided with two rectifier chips, one end of one rectifier chip is connected to the network transmission circuit, and one end of the other rectifier chip is connected to the POE power supply. The other ends of the two rectifier chips are both connected to the handshake protocol circuit, and the step-down circuit is respectively connected to the handshake protocol circuit and the power supply output end.

[0006] The rectifier bridge is equipped with two rectifier chips. The component layout on the PCB board is optimized through the rectifier bridge, step-down circuit and handshake protocol circuit, thereby reducing production costs and improving economic benefits.

[0007] Furthermore, the POE power supply circuit includes a capacitive reactance circuit, one end of the capacitive reactance circuit is grounded, and the other end of the capacitive reactance circuit is respectively connected to the step-down circuit and the handshake protocol circuit.

[0008] Through the capacitive reactance circuit, the POE power supply circuit can effectively suppress voltage fluctuations and electromagnetic interference, improve the stability of the power supply, reduce electromagnetic interference, and improve reliability.

[0009] Furthermore, the POE power supply circuit includes a first voltage stabilizing diode, one end of the first voltage stabilizing diode is connected to the capacitive reactance circuit, and the other end of the first voltage stabilizing diode is grounded.

[0010] By introducing the first voltage regulator diode into the POE power supply circuit, a stable voltage output can be provided when the input voltage fluctuates, effectively improving the power supply stability, protecting the circuit when the input voltage is too high, and reducing the risk of circuit damage.

[0011] Furthermore, the handshake protocol circuit includes a first resistor, a second resistor, a first diode, a second diode and a MOS tube, the drain of the MOS tube is connected to the capacitive reactance circuit, the source of the MOS tube, one end of the second resistor and one end of the second diode are all grounded, the rectifier chip, one end of the first diode and one end of the first resistor are connected in sequence, and the other end of the first resistor, the other end of the second resistor and the other end of the second diode are all connected to the gate of the MOS tube.

[0012] Through the handshake protocol circuit, the electrical signals can be matched effectively, the compatibility and reliability can be improved, the occurrence of failures can be reduced, and the maintenance cost can be lowered.

[0013] Furthermore, the POE power supply circuit includes a TVS tube, one end of the TVS tube is connected to the first diode and the rectifier chip respectively, and the other end of the TVS tube is grounded.

[0014] By introducing TVS tubes into the POE power supply circuit, it can respond quickly when the input voltage is abnormal, provide overvoltage protection, effectively prevent equipment damage, and improve safety.

[0015] Furthermore, the POE power supply circuit includes a first capacitor, one end of the first capacitor is connected to the first diode, and the other end of the first capacitor is grounded.

[0016] By introducing the first capacitor into the POE power supply circuit, the input voltage can be filtered, voltage fluctuations and electromagnetic interference can be effectively suppressed, and the stability of the power supply can be improved.

[0017] Furthermore, the POE power supply circuit includes a second voltage regulator diode, one end of which is connected to the rectifier chip, and the other end of which is grounded, so as to protect the circuit when the input voltage is too high.

[0018] Furthermore, the POE power supply circuit is provided with two second voltage regulator diodes, and one second voltage regulator diode is arranged in pair with one rectifier chip.

[0019] The two second voltage-stabilizing diodes can reduce the risk of common-mode lightning strikes and differential-mode lightning strikes when the input voltage fluctuates, thereby improving product safety.

[0020] Furthermore, the POE power supply circuit includes a second capacitor, and two ends of the second capacitor are respectively connected to two second voltage stabilizing diodes.

[0021] The second capacitor can filter the input voltage, effectively suppressing voltage fluctuations and electromagnetic interference. The second capacitor and the second voltage-stabilizing diode can promptly direct voltage fluctuations to the ground, thereby improving safety and stability.

[0022] The present application also provides a POE power supply system, which includes the POE power supply circuit described in any one of the above items.

[0023] Compared with the prior art, the present invention has the following beneficial effects: one end of a rectifier chip is connected to a network transmission circuit, one end of another rectifier chip is connected to a POE power supply, and the other ends of both rectifier chips are connected to a handshake protocol circuit. The step-down circuit is connected to the handshake protocol circuit and the power output terminal, respectively. Because the POE power supply circuit uses a rectifier bridge and a step-down circuit, it ensures stable power supply. Through the handshake protocol circuit, the POE power supply circuit can achieve effective communication with the powered device (PD). The rectifier bridge is equipped with two rectifier chips. The rectifier bridge, step-down circuit, and handshake protocol circuit optimize the component layout on the PCB board, reduce the number of components, reduce the occupied PCB space, and thus reduce production costs and improve economic benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 A schematic diagram of a POE power supply circuit provided in an embodiment of the present application; and Figure 2 A system diagram of a POE power supply circuit provided in an embodiment of the present application.

[0025] Description of reference numerals: 100, network transmission circuit; 200, rectifier bridge; 210, rectifier chip; 300, step-down circuit; 400, handshake protocol circuit; 410, first resistor; 420, second resistor; 430, first diode; 440, second diode; 450, MOS tube; 500, capacitive reactance circuit; 600, first voltage-stabilizing diode; 700, TVS tube; 810, first capacitor; 820, second capacitor; 900, second voltage-stabilizing diode; Vin, POE power supply; Vout, power supply output terminal. DETAILED DESCRIPTION

[0026] The specific implementation methods of this application are described in detail below with reference to the accompanying drawings.

[0027] It should be noted that, unless there is a conflict, the embodiments and technical features in the embodiments of this application can be combined with each other, and the detailed description in the specific implementation method should be understood as an explanation of the purpose of this application and should not be regarded as an improper restriction on this application.

[0028] It should be understood that the orientation or positional relationship is based on the orientation or positional relationship shown in the accompanying drawings. These orientation terms are only used to facilitate the description of this application and simplify the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation. Therefore, they should not be understood as limiting this application.

[0029] Figure 1 A schematic diagram of a POE power supply circuit provided in an embodiment of the present application is provided. Figure 2 A system diagram of a POE power supply circuit provided in an embodiment of the present application.

[0030] like Figure 1 and Figure 2 As shown, an embodiment of the present application provides a POE power supply circuit, which includes: a network transmission circuit 100, a rectifier bridge 200, a step-down circuit 300 and a handshake protocol circuit 400. The rectifier bridge 200 is provided with two rectifier chips 210, one end of one rectifier chip 210 is connected to the network transmission circuit 100, and one end of the other rectifier chip 210 is connected to the POE power supply Vin. The other ends of the two rectifier chips 210 are both connected to the handshake protocol circuit 400, and the step-down circuit 300 is respectively connected to the handshake protocol circuit 400 and the power supply output end Vout.

[0031] Specifically, the network transmission circuit 100 transmits network signals to the rectifier bridge 200. The network transmission circuit 100 can utilize existing Ethernet Category 5 cabling infrastructure to achieve data signal transmission. The rectifier bridge 200 includes two rectifier chips 210. One end of one rectifier chip 210 is connected to the network transmission circuit 100, while one end of the other rectifier chip 210 is connected to the POE power supply Vin. The other ends of both rectifier chips 210 are connected to the handshake protocol circuit 400. Through the rectifier bridge 200, a stable voltage input is provided to the subsequent step-down circuit 300. The handshake protocol circuit 400 is used to facilitate communication between the PSE device and the PD device to ensure a safe and stable power supply process. For example, the handshake protocol circuit 400 can utilize standards such as IEEE 802.3af / at / bt. The step-down circuit 300 is connected to the handshake protocol circuit 400 and the power output terminal Vout. The step-down circuit 300 reduces the DC voltage output by the rectifier bridge 200 to a voltage level suitable for the PD device and then provides it to the PD device. In the POE power supply circuit, the above-mentioned circuit modules are integrated on a single PCB board, and the PCB board component layout is optimized to achieve a miniaturized product design. At the same time, attention is paid to minimizing the use of components during the design process to reduce costs.

[0032] It should be noted that in the POE power supply circuit of the present embodiment, the POE power supply circuit utilizes a rectifier bridge 200 and a step-down circuit 300 to ensure stable power supply. Through the handshake protocol circuit, the POE power supply circuit is able to achieve effective communication with the powered device (PD). The rectifier bridge 200 includes two rectifier chips 210. The rectifier bridge 200, step-down circuit 300, and handshake protocol circuit 400 optimize the component layout on the PCB, reducing the number of components and occupying less PCB space, thereby lowering production costs and improving economic efficiency.

[0033] In some embodiments, the POE power supply circuit includes a capacitive reactance circuit 500 , one end of the capacitive reactance circuit 500 is grounded, and the other end of the capacitive reactance circuit 500 is connected to the step-down circuit 300 and the handshake protocol circuit 400 , respectively.

[0034] Specifically, the capacitive reactance circuit 500 includes multiple capacitors, which reduce voltage fluctuations and ripples through the capacitive reactance circuit 500, thereby improving the stability and quality of the power supply. Among them, one end of the capacitive reactance circuit 500 is grounded to ensure the safety and stability of the circuit. The other end of the capacitive reactance circuit 500 is connected to the step-down circuit 300 and the handshake protocol circuit 400 respectively, thereby reducing the impact of capacitor filtering on the step-down circuit 300 and the handshake protocol circuit 400 during the power supply process, thereby improving their operating stability. The step-down circuit 300 is provided with a step-down chip, which reduces the higher voltage output by the rectifier bridge 200 to a voltage level suitable for the operation of the PD device through the step-down chip.

[0035] Through the capacitive reactance circuit 500 , the POE power supply circuit can effectively suppress voltage fluctuations and electromagnetic interference, improve the stability of the power supply, reduce electromagnetic interference, and improve reliability.

[0036] In some embodiments, the POE power supply circuit includes a first zener diode 600 , one end of the first zener diode 600 is connected to the capacitive reactance circuit 500 , and the other end of the first zener diode 600 is grounded.

[0037] Specifically, the cathode of the first zener diode 600 is connected to the capacitive reactance circuit 500, and the anode of the first zener diode 600 is grounded, thereby reducing interference and ensuring the safety and reliability of the circuit. In particular, there can be multiple first zener diodes 600, and multiple first zener diodes 600 are arranged in parallel.

[0038] By introducing the first voltage regulator diode 600 into the POE power supply circuit, a stable voltage output can be provided when the input voltage fluctuates, thereby effectively improving the stability of the power supply, protecting the circuit when the input voltage is too high, and reducing the risk of circuit damage.

[0039] In some embodiments, the handshake protocol circuit 400 includes a first resistor 410, a second resistor 420, a first diode 430, a second diode 440 and a MOS tube 450, the drain of the MOS tube 450 is connected to the capacitive circuit 500, the source of the MOS tube 450, one end of the second resistor 420 and one end of the second diode 440 are all grounded, the rectifier chip 210, one end of the first diode 430 and one end of the first resistor 410 are connected in sequence, and the other end of the first resistor 410, the other end of the second resistor 420 and the other end of the second diode 440 are all connected to the gate of the MOS tube 450.

[0040] Specifically, the drain of MOS transistor 450 is connected to capacitive reactance circuit 500, which includes multiple capacitors. The source of MOS transistor 450, one end of second resistor 420, and one end of second diode 440 are grounded. Grounding can use the circuit ground wire or other grounding point to ensure circuit safety and stability. Rectifier chip 210 and one end of first diode 430 are connected to one end of first resistor 410 in sequence. The other ends of first resistor 410, second resistor 420, and second diode 440 are all connected to the gate of MOS transistor 450.

[0041] The handshake protocol circuit 400 can effectively match electrical signals, improve compatibility and reliability, reduce the occurrence of faults, and lower maintenance costs.

[0042] In some embodiments, the POE power supply circuit includes a TVS tube 700 , one end of the TVS tube 700 is connected to the first diode 430 and the rectifier chip 210 respectively, and the other end of the TVS tube 700 is grounded.

[0043] Specifically, the TVS diode 700, as a transient voltage suppressor, can quickly respond to transient voltages, absorb overvoltage in the circuit, and protect other components from damage. One end of the TVS diode 700 is connected to the first diode 430, and the other end of the TVS diode 700 is connected to the rectifier chip 210. The other end of the TVS diode 700 is grounded. The grounding can be done using the circuit ground wire or other grounding point to ensure circuit safety and stability.

[0044] By introducing the TVS diode 700 into the POE power supply circuit, it can respond quickly when the input voltage is abnormal, provide overvoltage protection, effectively prevent equipment damage, and improve safety.

[0045] In some embodiments, the POE power supply circuit includes a first capacitor 810 , one end of the first capacitor 810 is connected to the first diode 430 , and the other end of the first capacitor 810 is grounded.

[0046] Specifically, one end of the first capacitor 810 is connected to the first diode 430, and the other end of the first capacitor 810 is grounded. The grounding can use the circuit ground wire or other grounding point to ensure the safety and stability of the circuit. Filtering and decoupling are performed through the first capacitor 810 to ensure the stability and reliability of the circuit.

[0047] By introducing the first capacitor 810 into the POE power supply circuit, the input voltage can be filtered, voltage fluctuations and electromagnetic interference can be effectively suppressed, and the stability of the power supply can be improved.

[0048] In some embodiments, the POE power supply circuit includes a second zener diode 900 , one end of the second zener diode 900 is connected to the rectifier chip 210 , and the other end of the second zener diode 900 is grounded.

[0049] Specifically, the cathode of the second zener diode 900 is connected to the rectifier chip 210, and one end of the anode of the second zener diode 900 is grounded. The grounding can be the circuit ground wire or other grounding point to ensure the safety and stability of the circuit.

[0050] In some embodiments, the POE power supply circuit is provided with two second voltage regulator diodes 900 , and one second voltage regulator diode 900 is provided in pair with one rectifier chip 210 .

[0051] Specifically, the two second voltage stabilizing diodes 900 are used to provide additional voltage stabilization protection. The cathode ends of the two second voltage stabilizing diodes 900 are connected to one end of the rectifier chip 210. The anodes of the two second voltage stabilizing diodes 900 are grounded to ensure the safety and stability of the circuit. The two second voltage stabilizing diodes 900 can reduce the risk of common-mode lightning strikes and differential-mode lightning strikes when the input voltage fluctuates, thereby improving product safety.

[0052] In some embodiments, the POE power supply circuit includes a second capacitor 820 , and two ends of the second capacitor 820 are respectively connected to two second voltage stabilizing diodes 900 .

[0053] Specifically, the two ends of the second capacitor 820 are respectively connected to the cathodes of the two second voltage-stabilizing diodes 900. One end of the cathode of the second voltage-stabilizing diode 900 is connected to the cathode of the rectifier chip 210, the second capacitor 820, and the cathode of the first diode 430. The second capacitor 820 can provide additional filtering between the two second voltage-stabilizing diodes 900, helping to smooth the output voltage of the rectifier chip 210 and reduce voltage ripple and noise. It should be noted that the second capacitor 820 needs to be selected according to the required circuit frequency and capacitance value to meet the circuit's filtering requirements.

[0054] The second capacitor 820 can filter the input voltage, effectively suppressing voltage fluctuations and electromagnetic interference. The second capacitor 820 and the second voltage-stabilizing diode 900 can timely guide voltage fluctuations to the ground, thereby improving safety and stability.

[0055] It should be understood that in the POE power supply circuit of the present application, the POE power (Vin) input through the network cable is rectified by two rectifier chips 210, transmitted to the POE handshake protocol circuit (handshake protocol circuit 400) through two resistors, and finally stepped down to 12V by the step-down circuit 300 to power the IPC circuit. Among them, the second capacitor 820, the first capacitor 810, and the devices between the second capacitor 820 and the first capacitor 810 can be added according to actual conditions. The first Zener diode 600 and the second Zener diode 900 are used to solve surge matching. One TVS diode 700 is used to solve common-mode lightning strikes, and the other TVS diode 700 is used to solve differential-mode lightning strikes. The capacitive reactance circuit 500 is provided with three capacitors, and the capacitive reactance circuit 500 is used for decoupling.

[0056] The handshake protocol circuit 400 includes a first resistor 410, a second resistor 420, a first diode 430, a second diode 440, and a MOS transistor 450, allowing POE to continuously power the back-end circuitry. The network transmission circuit 100 includes a network transformer and multiple resistors, which together form a network transformer and multiple resistors. The network transmission circuit 100 is used to transmit network signals. The network transmission circuit 100 also includes a TVS diode, which is an anti-static diode to prevent static electricity from being introduced from outside the network cable.

[0057] The present application also provides a POE power supply system, which includes the POE power supply circuit described in any one of the above items.

[0058] The above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the above embodiments, it is still possible for those skilled in the art to modify the technical solutions described in the above embodiments, or to replace some of the technical features therein with equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions claimed to be protected by the present application.

Claims

1. A POE power supply circuit, characterized in that: The POE power supply circuit includes: a network transmission circuit, a rectifier bridge, a step-down circuit and a handshake protocol circuit. The rectifier bridge is provided with two rectifier chips, one end of one rectifier chip is connected to the network transmission circuit, and one end of the other rectifier chip is connected to the POE power supply. The other ends of the two rectifier chips are both connected to the handshake protocol circuit, and the step-down circuit is respectively connected to the handshake protocol circuit and the power supply output end.

2. A POE power supply circuit according to claim 1, characterized in that: The POE power supply circuit includes a capacitive reactance circuit, one end of the capacitive reactance circuit is grounded, and the other end of the capacitive reactance circuit is connected to the step-down circuit and the handshake protocol circuit respectively.

3. A POE power supply circuit according to claim 2, characterized in that: The POE power supply circuit includes a first voltage stabilizing diode, one end of the first voltage stabilizing diode is connected to the capacitive reactance circuit, and the other end of the first voltage stabilizing diode is grounded.

4. A POE power supply circuit according to claim 2, characterized in that: The handshake protocol circuit includes a first resistor, a second resistor, a first diode, a second diode and a MOS tube. The drain of the MOS tube is connected to the capacitive reactance circuit, the source of the MOS tube, one end of the second resistor and one end of the second diode are all grounded, the rectifier chip, one end of the first diode and one end of the first resistor are connected in sequence, and the other end of the first resistor, the other end of the second resistor and the other end of the second diode are all connected to the gate of the MOS tube.

5. A POE power supply circuit according to claim 4, characterized in that: The POE power supply circuit includes a TVS tube, one end of the TVS tube is connected to the first diode and the rectifier chip respectively, and the other end of the TVS tube is grounded.

6. A POE power supply circuit according to claim 4, characterized in that: The POE power supply circuit includes a first capacitor, one end of the first capacitor is connected to the first diode, and the other end of the first capacitor is grounded.

7. The POE power supply circuit according to claim 1, characterized in that: The POE power supply circuit includes a second voltage regulator diode, one end of the second voltage regulator diode is connected to the rectifier chip, and the other end of the second voltage regulator diode is grounded.

8. A POE power supply circuit according to claim 7, characterized in that: The POE power supply circuit is provided with two second voltage-stabilizing diodes, and one second voltage-stabilizing diode is arranged in pair with one rectifier chip.

9. A POE power supply circuit according to claim 8, characterized in that: The POE power supply circuit includes a second capacitor, and two ends of the second capacitor are respectively connected to the two second voltage stabilizing diodes.

10. A POE power supply system, characterized in that: The POE power supply system includes the POE power supply circuit according to any one of claims 1 to 9.

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