A POE power supply circuit

Abstract

The utility model discloses a kind of POE power supply circuit, comprising: power supply module, first conversion module, second conversion module, third conversion module and ethernet module;The power supply module is connected respectively the second conversion module and third conversion module by first conversion module;The ethernet module connects the power supply module. By cascading design makes every stage conversion work in high-efficiency interval, overall energy efficiency is high, heat loss is small, and provides the pure power with ripple minimum for subsequent chip, ensures system stable operation.

Description

Technical Field

[0001] This utility model relates to the field of Power over Ethernet (PoE) technology, specifically to a PoE power supply circuit. Background Technology

[0002] Power over Ethernet (PoE) is a technology that allows data and power to be transmitted simultaneously over standard Ethernet cables. This technology greatly simplifies the installation and deployment of network devices, as powered devices (PDs) such as network cameras, wireless access points, and IP phones no longer need to rely on separate power cords and adapters, thus reducing costs and improving cabling flexibility and tidiness.

[0003] Traditional PoE systems typically include a power supply equipment (PSE) and a power receiving equipment (PD). The PoE circuit at the D end usually needs to perform two core tasks: first, to safely and compliantly extract power from the network cable; and second, to convert the extracted unstable, high-voltage DC power into various stable, low-voltage DC power required by the internal chips of the device.

[0004] Traditional PoE power receiving circuit design faces several common challenges. First, the conversion efficiency after power extraction is crucial; inefficient conversion leads to severe overheating, impacting stability and lifespan. Second, voltage fluctuations and noise interference from the network cable can directly affect the normal operation of downstream circuits, necessitating robust filtering and protection mechanisms. Third, modern network equipment is complex and often requires multiple operating voltages (e.g., 12V, 5V, 3.3V, 1.8V), demanding a power supply architecture with multiple, stable, and clean outputs. Furthermore, the entire circuit must also meet electromagnetic compatibility (EMC) requirements and integrate comprehensive protection functions to withstand surges such as lightning strikes and electrostatic discharge (ESD). Utility Model Content

[0005] To overcome the above-mentioned technical defects, this utility model provides a POE power supply circuit.

[0006] To solve the above problems, this utility model is implemented according to the following technical solution:

[0007] The present invention discloses a PoE power supply circuit comprising: a power supply module, a first conversion module, a second conversion module, a third conversion module, and an Ethernet module; the power supply module is connected to the second conversion module and the third conversion module respectively through the first conversion module; the Ethernet module is connected to the power supply module.

[0008] Preferably, the Ethernet module includes: a network transformer, a first capacitor, a second capacitor, a third capacitor, a fourth capacitor, a fifth capacitor, a sixth capacitor, a first resistor, a second resistor, a third resistor, a seventh capacitor, a network interface, and a first iron-core inductor; the TDC pin of the network transformer is grounded through the first capacitor; the RDC pin of the network transformer is grounded through the second capacitor; the TXN pin of the network transformer is connected to one end of the first resistor through the third capacitor, and the other end of the first resistor is grounded through the fifth capacitor; the RXC pin of the network transformer is connected to one end of the second resistor through the fourth capacitor, and the other end of the second resistor is grounded through the sixth capacitor; the TD+ pin of the network interface is connected to... The TXP pin of the network transformer is connected to the TXM pin of the network interface; the RX+ pin of the network interface is connected to the RXP pin of the network transformer, and the RX- pin of the network interface is connected to the RXM pin of the network transformer; the G+ pin and the Y+ pin of the network interface are both connected to the third conversion module through the first iron core inductor, and the G+ pin and the Y+ pin of the network interface are both grounded through the seventh capacitor; the GND2 pin and the GND3 pin of the network interface are both grounded through the third resistor.

[0009] Preferably, the power supply module includes: a first rectifier bridge, a second rectifier bridge, a fourth resistor, a fifth resistor, a first Zener diode, a second Zener diode, a first MOSFET, a sixth resistor, an eighth capacitor, a seventh resistor, an eighth resistor, a first light-emitting diode, a ninth resistor, a tenth resistor, a third Zener diode, a first transistor, an eleventh resistor, a ninth capacitor, a tenth capacitor, a twelfth resistor, a thirteenth resistor, a fourteenth resistor, a fifteenth resistor, a sixteenth resistor, a seventeenth resistor, an eighteenth resistor, a nineteenth resistor, a twentieth resistor, a twenty-first resistor, an eleventh capacitor, a twelfth capacitor, a thirteenth capacitor, a fourteenth capacitor, a fifteenth capacitor, a sixteenth capacitor, a fourth Zener diode, and Power over Ethernet (PoE). The controller; the AC1 pin of the first rectifier bridge is connected to one end of the fourth resistor through the ninth capacitor, and the other end of the fourth resistor is connected to ground through the sixth resistor; the AC pin of the first rectifier bridge is connected to one end of the fifth resistor through the tenth capacitor, and the other end of the fifth resistor is connected to ground through the sixth resistor; the positive terminal of the first rectifier bridge is connected to the negative terminal of the first rectifier bridge through the sixth resistor; the AC1 pin of the second rectifier bridge is connected to the RXC pin of the network transformer, and the AC pin of the second rectifier bridge is connected to the TXN pin of the network transformer; the positive terminal of the second rectifier bridge is connected to the negative terminal of the second rectifier bridge through the twenty-first resistor; the seventh resistor is connected to the first Zener diode... The diodes are respectively connected to one end of the eighth resistor, the cathode of the second Zener diode, and the first pin of the first MOSFET; one end of the seventh resistor is connected to the anode of the second rectifier bridge; the other end of the eighth resistor is respectively connected to the anode of the second Zener diode, the second pin of the first MOSFET, and the cathode of the second rectifier bridge; the third pin of the first MOSFET is grounded; the AUX pin of the Power over Ethernet controller is connected to the anode of the second rectifier bridge through the ninth resistor; the FTY pin of the Power over Ethernet controller is connected to the CLASS pin of the Power over Ethernet controller through the tenth resistor; the AUX pin of the Power over Ethernet controller is respectively connected to one end of the eleventh capacitor. The eleventh capacitor is connected to the anode of the third Zener diode, the VSS pin of the Power over Ethernet (PoE) controller, and the VSS1 pin of the PoE controller. The other end of the eleventh capacitor is connected to the cathode of the third Zener diode and one end of the eleventh resistor. The other end of the eleventh resistor is connected to the EN pin and the PG pin of the PoE controller. The T2P pin of the PoE controller is connected to the cathode of the first LED, and the anode of the first LED is connected to one end of the eleventh resistor via the twelfth resistor. The DET pin of the PoE controller is connected to one end of the eleventh resistor via the twelfth resistor.One end of the thirteenth resistor is connected to one end of the fourteenth resistor and one end of the eleventh resistor, respectively. The other end of the thirteenth resistor is connected to the cathode of the fourth Zener diode and the base of the first transistor, respectively. The emitter of the first transistor is connected to the VIN pin of the Power over Ethernet (PoE) controller, and the collector of the first transistor is connected to the other end of the fourteenth resistor. The NC5, NC6, and NC7 pins of the PoE controller are all connected to the VIN pin of the PoE controller through the twelfth capacitor and are grounded. The GATE pin of the PoE controller is grounded through the thirteenth capacitor. The ISENS pin of the PoE controller is connected to one end of the fifteenth resistor and one end of the sixteenth resistor, respectively. The other end of the sixteenth resistor is connected to one end of the seventeenth resistor and one end of the eighteenth resistor, respectively. The other end of the 18th resistor is grounded; the FB pin of the Power over Ethernet (PoE) controller is grounded through the 19th resistor; the COMP pin of the PoE controller is grounded through the 14th capacitor; the VCC pin of the PoE controller is connected to the other end of the 15th resistor and one end of the 15th capacitor, the other end of the 15th capacitor being grounded; the SS pin of the PoE controller is grounded through the 16th capacitor; the RT pin of the PoE controller is grounded through the 20th resistor; the RTN pin, RTN1 pin, GND1 pin, GND pin, NC1 pin, NC2 pin, NC3 pin, and NC4 pin of the PoE controller are all grounded.

[0010] Preferably, the first conversion module includes: a third rectifier bridge, a seventeenth capacitor, an eighteenth capacitor, a nineteenth capacitor, a step-down controller, a twentieth capacitor, a twenty-second resistor, a twenty-third resistor, a twenty-fourth resistor, a twenty-fifth resistor, a twenty-sixth resistor, a twenty-seventh resistor, a twenty-eighth resistor, a twenty-ninth resistor, a twenty-first capacitor, a twenty-second capacitor, a twenty-third capacitor, a twenty-fourth capacitor, a twenty-fifth capacitor, a twenty-sixth capacitor, a second MOSFET, a third MOSFET, a thirtieth resistor, a thirty-first resistor, a thirty-second resistor, a thirty-third resistor, a thirty-fourth resistor, a thirty-fifth resistor, a thirty-sixth resistor, a thirty-seventh resistor, a thirty-eighth resistor, a twenty-seventh capacitor, a twenty-eighth capacitor, and a twenty-ninth capacitor; The AC1 pin of the third rectifier bridge is connected to the AC1 pin of the first rectifier bridge, and the AC pin of the third rectifier bridge is connected to the AC pin of the first rectifier bridge. The positive terminal of the third rectifier bridge is connected to one end of the seventeenth capacitor, one end of the eighteenth capacitor, and one end of the nineteenth capacitor, respectively. The other ends of the seventeenth, eighteenth, and nineteenth capacitors are all grounded. The IN pin of the buck controller is grounded through the nineteenth capacitor. The FREQ pin of the buck controller is grounded through the twenty-second resistor. The PG pin of the buck controller is connected to the VCC1 pin of the buck controller through the twenty-third resistor, and the VCC1 pin of the buck controller is connected through the twentyth capacitor. Grounded; the VCC2 pin of the buck controller outputs 12V through the 24th resistor, and the VCC2 pin of the buck controller is grounded through the 21st capacitor; the SYNCO pin of the buck controller is grounded through the 25th resistor; the EN / SYNC pin of the buck controller is connected to the positive terminal of the second rectifier bridge through the 26th resistor, the EN / SYNC pin of the buck controller is grounded through the 27th resistor, and the EN / SYNC pin of the buck controller is grounded through the 22nd capacitor; the CCM / AAM pin of the buck controller is connected to one end of the 23rd capacitor and one end of the 28th resistor, and the other end of the 23rd capacitor and the second... The other ends of the eighteen resistors are all grounded; the COMP pin of the buck controller is connected to one end of the twenty-fourth capacitor and one end of the twenty-fifth capacitor respectively, the other end of the twenty-fourth capacitor is connected to the other end of the twenty-fifth capacitor through the twenty-ninth resistor, and the other end of the twenty-fifth capacitor is grounded; the BST pin of the buck controller is connected to one end of the twenty-sixth capacitor through the thirtieth resistor, the other end of the twenty-sixth capacitor is connected to the SW pin of the buck controller, one end of the first inductor, and one end of the thirty-first resistor respectively; the SENSE+ pin of the buck controller is connected to the other end of the first inductor and one end of the thirty-third resistor respectively through the thirty-second resistor;The SENSE+ pin of the buck controller is connected to the other end of the 33rd resistor, the positive terminal of the electrolytic capacitor, and one end of the 27th capacitor via the 34th resistor. The negative terminal of the electrolytic capacitor and the other end of the 27th capacitor are both grounded. The FB pin of the buck controller is connected to the other end of the 33rd resistor via the 35th resistor. The FB pin of the buck controller is grounded via the 36th resistor. The ILIM pin of the buck controller is grounded via the 37th resistor. The SS pin of the buck controller is grounded via the 28th capacitor. The fourth pin of the second MOSFET is connected to the TG pin of the buck controller. The first, second, and third pins of the second MOSFET are all connected to the SW pin of the buck controller. The fourth pin of the third MOSFET is connected to the BG pin of the buck controller via the 38th resistor. The fifth, sixth, seventh, eighth, and ninth pins of the third MOSFET are all connected to one end of the first inductor. One end of the 29th capacitor is connected to the other end of the 31st resistor. The other end of the 29th capacitor is grounded. ;

[0011] Preferably, the second conversion module includes: a DC-DC converter, a 30th capacitor, a 31st capacitor, a 32nd capacitor, a 33rd capacitor, a 34th capacitor, a 35th capacitor, a 36th capacitor, a 37th capacitor, a 39th resistor, a 40th resistor, a 41st resistor, and a 42nd resistor; the VIN pin of the DC-DC converter is connected to one end of the 30th capacitor, one end of the 31st capacitor, and one end of the 39th resistor, respectively; the other ends of the 30th capacitor and the 31st capacitor are both grounded; the EN pin of the DC-DC converter is connected to the other end of the 39th resistor; the LX pin of the DC-DC converter is connected to... One end of the iron-core inductor and one end of the thirty-second capacitor are connected; the BS pin of the DC-DC converter is connected to the other end of the thirty-third capacitor; one end of the fortieth resistor is connected to one end of the thirty-fourth capacitor, one end of the thirty-fifth capacitor, one end of the thirty-sixth capacitor, one end of the thirty-seventh capacitor, and one end of the forty-first resistor, respectively; the other end of the fortieth resistor is connected to the FB / OUT pin of the DC-DC converter, one end of the forty-second resistor, and the other end of the thirty-fourth capacitor, respectively; the other ends of the thirty-fifth capacitor, the thirty-sixth capacitor, the thirty-seventh capacitor, and the forty-second resistor are all grounded.

[0012] Preferably, it further includes: a 4G module, an OTG circuit, and a control module; the 4G module includes a step-down circuit and a 4G circuit; the step-down circuit is connected to the second conversion module and the 4G circuit respectively; the 4G circuit is connected to the OTG circuit and the control module respectively.

[0013] Preferably, the 4G circuit includes: a connector, a 38th capacitor, a 39th capacitor, a 40th capacitor, a 41st capacitor, a 42nd capacitor, a 43rd capacitor, a 44th capacitor, a first electrostatic discharge (ESD) protection diode, a SIM card interface, a SIM card, a first ESD suppressor, a second ESD suppressor, a third ESD suppressor, a 43rd resistor, a 44th resistor, a 45th resistor, a 46th resistor, and a 47th resistor; the 3.3V_2 pin, the +3.3Vaux pin, the 3.3V_1 pin, the Reserved4 pin, and the Reserved5 pin of the connector are each connected to one end of the 38th capacitor and the... One end of the 39th capacitor, and the other ends of the 38th and 39th capacitors are both grounded; the REFCLK- pin of the connector is connected to one end of the 40th capacitor through the 43rd resistor, and the other end of the 40th capacitor is grounded; the W_DISABLE pin of the connector is connected to one end of the 45th resistor through the 44th resistor; the PERST pin of the connector is connected to the other ends of the 45th and 46th resistors respectively; the first pin of the first electrostatic discharge protection diode is connected to the DATA pin of the SIM card interface and the UIM_DATA pin of the connector respectively; the third pin of the first electrostatic discharge protection diode is connected to the SIM card interface... The CLK pin of the SIM card interface and the UIM_CLK pin of the connector; the sixth pin of the first electrostatic discharge (ESD) diode is connected to the RESET pin of the SIM card interface and the UIM_RESET pin of the connector; the fifth pin of the first ESD diode is connected to the UIM_PWR pin and the UIM_VPP pin of the connector; the DATA pin of the SIM card interface is connected to one end of the forty-seventh resistor, one end of the forty-first capacitor, one end of the first ESD suppressor, and the seventh pin of the SIM card; the other end of the forty-first capacitor and the other end of the first ESD suppressor are both grounded; the CLK pin of the SIM card interface is... Connect one end of the forty-second capacitor, one end of the second electrostatic discharge suppressor, and the eighth pin of the SIM card. The other ends of the forty-second capacitor and the second electrostatic discharge suppressor are both grounded. The VPP pin of the SIM card interface is connected to the other end of the forty-seventh resistor, the VCC pin of the SIM card interface, and one end of the forty-third capacitor. The other end of the forty-third capacitor is grounded. The GND1 pin of the SIM card interface is grounded. The RESET pin of the SIM card interface is connected to the ninth pin of the SIM card, one end of the forty-fourth capacitor, and one end of the third electrostatic discharge suppressor. The other ends of the forty-fourth capacitor and the third electrostatic discharge suppressor are both grounded.

[0014] Preferably, the OTG circuit includes: a USB interface, a second electrostatic discharge (ESD) protection diode, a second transistor, a fourth MOSFET, a forty-eighth resistor, a forty-ninth resistor, a fiftieth resistor, a fifty-first resistor, a fifty-second resistor, a fifty-third resistor, a forty-fifth capacitor, a forty-sixth capacitor, and a diode; the first pin of the USB interface is connected to the first pin of the second ESD protection diode, one end of the forty-fifth capacitor, one end of the forty-sixth capacitor, the third pin of the fourth MOSFET, and one end of the forty-eighth resistor; the second pin of the USB interface is connected to the sixth pin of the second ESD protection diode; the third pin of the USB interface is connected to the fourth pin of the second ESD protection diode; The fourth pin of the USB interface is connected to the emitter of the second transistor through the forty-ninth resistor, and the fourth pin of the USB interface is connected to the third conversion module through the fiftieth resistor; the second pin of the fourth MOSFET is connected to the other end of the forty-eighth resistor, one end of the fifty-first resistor, one end of the fifty-second resistor, and the cathode of the diode, respectively, and the other end of the fifty-second resistor is connected to the anode of the diode; the first pin of the fourth MOSFET is connected to the other end of the fifty-first resistor and the collector of the second transistor, and the base of the second transistor is connected to one end of the fifty-third resistor; the other ends of the forty-fifth capacitor and the forty-sixth capacitor are both grounded.

[0015] Preferably, it includes: a WiFi module circuit and an ETC circuit; the WiFi module circuit is respectively connected to the second conversion module, the third conversion module, the ETC circuit and the control module; the control module is connected to the ETC circuit.

[0016] Preferably, it includes: a Bluetooth module circuit, which is connected to the third conversion module and the control module respectively.

[0017] Compared with the prior art, the beneficial effects of this utility model are:

[0018] The circuit employs a multi-stage high-efficiency conversion architecture. The first conversion module, as the core buck unit, utilizes synchronous rectification technology to significantly reduce conduction losses caused by traditional diode freewheeling, achieving efficient conversion from the PoE input voltage to the intermediate bus voltage. The second conversion module further provides accurate and stable low-voltage output. This cascaded design ensures that each conversion stage operates within its high-efficiency range, resulting in high overall energy efficiency, low heat loss, and a clean power supply with minimal ripple for subsequent chips, guaranteeing stable system operation.

[0019] The core functionality of this solution is implemented by integrated dedicated chips (such as PoE controllers, buck controllers, and DC-DC converters), encapsulating complex detection, control, protection, and power switching functions internally. This greatly simplifies the peripheral circuitry, reduces the number of components, lowers PCB layout complexity and production costs, while improving design consistency and overall reliability. Attached Figure Description

[0020] The specific embodiments of this utility model will be further described in detail below with reference to the accompanying drawings, wherein:

[0021] Figure 1 This is the circuit schematic diagram of the power supply module of this utility model.

[0022] Figure 2 This is the circuit schematic diagram of the first conversion module of this utility model.

[0023] Figure 3 This is the circuit schematic diagram of the second conversion module of this utility model.

[0024] Figure 4 This is the circuit schematic diagram of the third conversion module of this utility model.

[0025] Figure 5 This is the circuit schematic diagram of the Ethernet module of this utility model.

[0026] Figure 6 This is the circuit schematic diagram of the 4G module of this utility model.

[0027] Figure 7 This is the schematic diagram of the OTG circuit of this utility model.

[0028] Figure 8 This is the circuit schematic diagram of the WiFi module of this utility model.

[0029] Figure 9 This is the schematic diagram of the ETC circuit of this utility model.

[0030] Figure 10 This is the circuit schematic diagram of the Bluetooth module of this utility model.

[0031] In the diagram: 1-Power supply module; 2-First conversion module; 3-Second conversion module; 4-Third conversion module; 5-Ethernet module; 6-4G module; 7-OTG circuit; 8-WiFi module circuit; 9-ETC circuit; 10-Bluetooth module circuit. Detailed Implementation

[0032] The preferred embodiments of the present invention will be described below with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0033] like Figures 1-10 As shown, this utility model discloses a preferred structure of a POE power supply circuit.

[0034] like Figures 1-5 As shown, a PoE power supply circuit includes: a power supply module 1, a first conversion module 2, a second conversion module 3, a third conversion module 4, and an Ethernet module 5; the power supply module 1 is connected to the second conversion module 3 and the third conversion module 4 through the first conversion module 2; the Ethernet module 5 is connected to the power supply module 1.

[0035] In a preferred embodiment, the Ethernet module 5 includes: a network transformer, a first capacitor, a second capacitor, a third capacitor, a fourth capacitor, a fifth capacitor, a sixth capacitor, a first resistor, a second resistor, a third resistor, a seventh capacitor, a network interface, and a first iron-core inductor; the TDC pin of the network transformer is grounded through the first capacitor; the RDC pin of the network transformer is grounded through the second capacitor; the TXN pin of the network transformer is connected to one end of the first resistor through the third capacitor, and the other end of the first resistor is grounded through the fifth capacitor; the RXC pin of the network transformer is connected to one end of the second resistor through the fourth capacitor, and the other end of the second resistor is grounded through the sixth capacitor; the TD+ pin of the network interface... The network interface's TXP pin is connected to the network transformer's TXM pin; the network interface's RX+ pin is connected to the network transformer's RXP pin; the network interface's RX- pin is connected to the network transformer's RXM pin; the network interface's G+ pin and Y+ pin are both connected to the third conversion module through the first iron core inductor; the network interface's G+ pin and Y+ pin are both grounded through the seventh capacitor; the network interface's GND2 pin and GND3 pin are both grounded through the third resistor.

[0036] Specifically, the network transformer is the core component for achieving physical layer electrical isolation. It isolates the sensitive PHY chip inside the device from the external network cable, effectively preventing damage to internal circuits from ground loop currents, surges, and high-voltage interference. The transformer transmits differential data signals (TXP / TXM, RXP / RXM) via magnetic coupling, while simultaneously blocking common-mode noise, improving anti-interference capabilities. The TDC and RDC pins are typically the center taps of the transformer's internal transmit and receive lines. Grounding them via the first and second capacitors provides a low-impedance return path for common-mode noise, further filtering out high-frequency common-mode interference and optimizing signal quality. The third capacitor, the first resistor, and the fifth capacitor constitute the RC filtering and capacitive coupling network for the TXN line. Similarly, the fourth capacitor, the second resistor, and the sixth capacitor constitute the corresponding network for the RXC line. The first core inductor is connected in series in the power (G+ / Y+) path. Ferrite beads or inductors present high impedance to high-frequency noise, effectively suppressing high-frequency common-mode interference transmitted or transmitted through the power lines. The third resistor connects the network interface shell (GND2, GND3) to system ground. This resistor (usually 0 ohms or a small value) is used to balance the potential and can also provide some isolation and discharge path in the event of an ESD event.

[0037] In a preferred embodiment, the power supply module 1 includes: a first rectifier bridge, a second rectifier bridge, a fourth resistor, a fifth resistor, a first Zener diode, a second Zener diode, a first MOSFET, a sixth resistor, an eighth capacitor, a seventh resistor, an eighth resistor, a first light-emitting diode, a ninth resistor, a tenth resistor, a third Zener diode, a first transistor, an eleventh resistor, a ninth capacitor, a tenth capacitor, a twelfth resistor, a thirteenth resistor, a fourteenth resistor, a fifteenth resistor, a sixteenth resistor, a seventeenth resistor, an eighteenth resistor, a nineteenth resistor, a twentieth resistor, a twenty-first resistor, an eleventh capacitor, a twelfth capacitor, a thirteenth capacitor, a fourteenth capacitor, a fifteenth capacitor, a sixteenth capacitor, a fourth Zener diode, and... Ethernet Power Supply Controller; the AC1 pin of the first rectifier bridge is connected to one end of the fourth resistor through the ninth capacitor, and the other end of the fourth resistor is connected to ground through the sixth resistor; the AC pin of the first rectifier bridge is connected to one end of the fifth resistor through the tenth capacitor, and the other end of the fifth resistor is connected to ground through the sixth resistor; the positive terminal of the first rectifier bridge is connected to the negative terminal of the first rectifier bridge through the sixth resistor; the AC1 pin of the second rectifier bridge is connected to the RXC pin of the network transformer, and the AC pin of the second rectifier bridge is connected to the TXN pin of the network transformer; the positive terminal of the second rectifier bridge is connected to the negative terminal of the second rectifier bridge through the twenty-first resistor; the seventh resistor is connected to the fourth resistor through the sixth capacitor ...1 pin of the second rectifier bridge is connected to the TXN pin of the network transformer; the AC1 pin of the second rectifier bridge is connected to the TXN pin of the network transformer, and the AC1 pin of the second rectifier bridge is connected to the TXN pin of the network transformer; the AC1 pin of the second rectifier bridge is connected to the TXN pin of the network transformer, and the AC1 pin of the second rectifier bridge is connected to the TXN pin of the network transformer, and the AC1 pin of the second rectifier bridge is connected to the TXN pin of the network transformer, and the AC1 pin of the second rectifier bridge is connected to the TXN pin of the network transformer, and the AC1 pin of the second rectifier bridge A Zener diode is connected to one end of the eighth resistor, the cathode of the second Zener diode, and the first pin of the first MOSFET. One end of the seventh resistor is connected to the anode of the second rectifier bridge. The other end of the eighth resistor is connected to the anode of the second Zener diode, the second pin of the first MOSFET, and the cathode of the second rectifier bridge. The third pin of the first MOSFET is grounded. The AUX pin of the Power over Ethernet (PoE) controller is connected to the anode of the second rectifier bridge via the ninth resistor. The FTY pin of the PoE controller is connected to the CLASS pin of the PoE controller via the tenth resistor. The AUX pin of the PoE controller is connected to the eleventh capacitor. One end of the eleventh capacitor is connected to the anode of the third Zener diode, the VSS pin of the Power over Ethernet (PoE) controller, and the VSS1 pin of the PoE controller; the other end of the eleventh capacitor is connected to the cathode of the third Zener diode and one end of the eleventh resistor, and the other end of the eleventh resistor is connected to the EN pin and the PG pin of the PoE controller; the T2P pin of the PoE controller is connected to the cathode of the first LED, and the anode of the first LED is connected to one end of the eleventh resistor through the twelfth resistor; the DET pin of the PoE controller is connected to one end of the eleventh resistor through the twelfth resistor.One end of the thirteenth resistor is connected to one end of the fourteenth resistor and one end of the eleventh resistor, respectively. The other end of the thirteenth resistor is connected to the cathode of the fourth Zener diode and the base of the first transistor, respectively. The emitter of the first transistor is connected to the VIN pin of the Power over Ethernet (PoE) controller, and the collector of the first transistor is connected to the other end of the fourteenth resistor. The NC5, NC6, and NC7 pins of the PoE controller are all connected to the VIN pin of the PoE controller through the twelfth capacitor and are grounded. The GATE pin of the PoE controller is grounded through the thirteenth capacitor. The ISENS pin of the PoE controller is connected to one end of the fifteenth resistor and one end of the sixteenth resistor, respectively. The other end of the sixteenth resistor is connected to one end of the seventeenth resistor and one end of the eighteenth resistor, respectively. The other end of the 18th resistor is grounded; the FB pin of the Power over Ethernet (PoE) controller is grounded through the 19th resistor; the COMP pin of the PoE controller is grounded through the 14th capacitor; the VCC pin of the PoE controller is connected to the other end of the 15th resistor and one end of the 15th capacitor, the other end of the 15th capacitor being grounded; the SS pin of the PoE controller is grounded through the 16th capacitor; the RT pin of the PoE controller is grounded through the 20th resistor; the RTN pin, RTN1 pin, GND1 pin, GND pin, NC1 pin, NC2 pin, NC3 pin, and NC4 pin of the PoE controller are all grounded.

[0038] Specifically, the AC pins of the first rectifier bridge are connected to the network transformer via resistors four and five, and capacitors nine and ten, forming a signal / power coupling path. Data signals and power are transmitted together through the transformer's center tap or specific pins (such as TXN, RXC). The two high-resistance resistors (fourth and fifth) are used for current limiting and isolation, while the capacitors are used to couple AC signals and block DC bias. The second rectifier bridge is directly connected to the TXN and RXC pins of the network transformer to perform full-wave rectification of the AC power from the network cable, converting it into pulsating DC. The dual rectifier bridge design ensures that the module can correctly receive and rectify power regardless of the wiring method used by the network equipment (PSE, power supply equipment), achieving polarity-independent connection. A simple voltage regulation and switching control circuit is formed by resistor seven, first Zener diode, eighth resistor, second Zener diode, and first MOSFET. Its function is to shut down the main power path before the input voltage reaches a stable threshold, preventing unstable voltage from impacting subsequent circuits. The VSS / VSS1 pin of the Power over Ethernet (PEE) controller is power ground, and the AUX pin draws its operating voltage from the rectified power supply. The EN / PG pin receives an enable / power signal from the eleventh resistor, eleventh capacitor, and third Zener diode. This RC network (eleventh resistor and eleventh capacitor) is used to generate a power-on reset signal or set the soft-start time. The PSE device first detects whether the connected device is a legitimate PD device and then determines its power level. The DET pin is used for detection. The PEE controller presents a standard detection signature resistor to the PSE through this pin and the twelfth resistor. The CLASS pin is used for classification. The PEE controller, through the tenth resistor and in conjunction with internal circuitry, tells the PSE device its required power level. The first LED may be used to indicate classification status or link status. Once detection and classification are complete, the PEE controller will turn on the internal power MOSFET or drive an external switch.

[0039] In a preferred embodiment, the first conversion module 2 includes: a third rectifier bridge, a seventeenth capacitor, an eighteenth capacitor, a nineteenth capacitor, a step-down controller, a twentieth capacitor, a twenty-second resistor, a twenty-third resistor, a twenty-fourth resistor, a twenty-fifth resistor, a twenty-sixth resistor, a twenty-seventh resistor, a twenty-eighth resistor, a twenty-ninth resistor, a twenty-first capacitor, a twenty-second capacitor, a twenty-third capacitor, a twenty-fourth capacitor, a twenty-fifth capacitor, a twenty-sixth capacitor, a second MOSFET, a third MOSFET, a thirtieth resistor, a thirty-first resistor, a thirty-second resistor, a thirty-third resistor, a thirty-fourth resistor, a thirty-fifth resistor, a thirty-sixth resistor, a thirty-seventh resistor, a thirty-eighth resistor, a twenty-seventh capacitor, a twenty-eighth capacitor, and a twentieth capacitor. Nine capacitors; the AC1 pin of the third rectifier bridge is connected to the AC1 pin of the first rectifier bridge, the AC pin of the third rectifier bridge is connected to the AC pin of the first rectifier bridge, the positive terminal of the third rectifier bridge is connected to one end of the seventeenth capacitor, one end of the eighteenth capacitor, and one end of the nineteenth capacitor respectively, and the other ends of the seventeenth capacitor, the eighteenth capacitor, and the nineteenth capacitor are all grounded; the IN pin of the buck controller is grounded through the nineteenth capacitor; the FREQ pin of the buck controller is grounded through the twenty-second resistor; the PG pin of the buck controller is connected to the VCC1 pin of the buck controller through the twenty-third resistor, and the VCC1 pin of the buck controller is connected through the second... The 10 capacitors are grounded; the VCC2 pin of the buck controller outputs 12V through the 24th resistor, and the VCC2 pin of the buck controller is grounded through the 21st capacitor; the SYNCO pin of the buck controller is grounded through the 25th resistor; the EN / SYNC pin of the buck controller is connected to the positive terminal of the second rectifier bridge through the 26th resistor, the EN / SYNC pin of the buck controller is grounded through the 27th resistor, and the EN / SYNC pin of the buck controller is grounded through the 22nd capacitor; the CCM / AAM pin of the buck controller is connected to one end of the 23rd capacitor and one end of the 28th resistor, and the other end of the 23rd capacitor is connected to the... The other end of the twenty-eighth resistor is grounded; the COMP pin of the buck controller is connected to one end of the twenty-fourth capacitor and one end of the twenty-fifth capacitor respectively, the other end of the twenty-fourth capacitor is connected to the other end of the twenty-fifth capacitor through the twenty-ninth resistor, and the other end of the twenty-fifth capacitor is grounded; the BST pin of the buck controller is connected to one end of the twenty-sixth capacitor through the thirtieth resistor, the other end of the twenty-sixth capacitor is connected to the SW pin of the buck controller, one end of the first inductor, and one end of the thirty-first resistor respectively; the SENSE+ pin of the buck controller is connected to the other end of the first inductor and one end of the thirty-third resistor respectively through the thirty-second resistor;The SENSE+ pin of the buck controller is connected to the other end of the 33rd resistor, the positive terminal of the electrolytic capacitor, and one end of the 27th capacitor via the 34th resistor. The negative terminal of the electrolytic capacitor and the other end of the 27th capacitor are both grounded. The FB pin of the buck controller is connected to the other end of the 33rd resistor via the 35th resistor. The FB pin of the buck controller is grounded via the 36th resistor. The ILIM pin of the buck controller is grounded via the 37th resistor. The SS pin of the buck controller is grounded via the 28th capacitor. The fourth pin of the second MOSFET is connected to the TG pin of the buck controller. The first, second, and third pins of the second MOSFET are all connected to the SW pin of the buck controller. The fourth pin of the third MOSFET is connected to the BG pin of the buck controller via the 38th resistor. The fifth, sixth, seventh, eighth, and ninth pins of the third MOSFET are all connected to one end of the first inductor. One end of the 29th capacitor is connected to the other end of the 31st resistor. The other end of the 29th capacitor is grounded. ;

[0040] Specifically, the input of the third rectifier bridge is connected in parallel with the first rectifier bridge, indicating that it receives AC power from the Ethernet cable. Its function is to work in conjunction with the preceding circuitry to ensure correct power polarity. A large-capacity input filter capacitor bank is formed at the output (positive) of the third rectifier bridge to smooth the pulsating DC after rectification, store energy, and provide a low-impedance power supply for subsequent switching circuits. The twentieth capacitor is the decoupling capacitor for the VCC1 pin of the buck controller, ensuring stable power supply to the control chip. The buck controller is the brain of the entire conversion circuit. Its EN / SYNC pin is connected to the preceding power supply through the twenty-sixth resistor to achieve automatic power-on. The twenty-seventh resistor and the twenty-second capacitor may form an RC delay circuit to suppress glitches during power-on and implement soft-start logic. The FREQ pin sets the switching frequency through the twenty-second resistor. The SYNCO pin is grounded through the twenty-fifth resistor, possibly for synchronous mode configuration. The CCM / AAM pin is connected to the twenty-third capacitor and the twenty-eighth resistor to set the converter's operating mode (such as continuous conduction mode CCM or discontinuous conduction mode DCM) and adaptive adjustment. The second MOSFET acts as the upper bridge arm switch, receiving the drive signal from the controller's TG pin via its fourth pin (gate). The third MOSFET acts as the lower bridge arm switch, receiving the drive signal from the controller's BG pin via its fourth pin (gate). When the upper bridge arm switch is on, current flows through the first inductor to supply power to the load, while the inductor stores energy. When the upper bridge arm switch is off and the lower bridge arm switch is on, the first inductor releases energy through the loop formed by the lower MOSFET, maintaining power supply to the load. The twenty-sixth capacitor and the thirtieth resistor form a bootstrap circuit, providing a charge pump for the gate drive voltage required to drive the upper MOSFET, ensuring that the upper MOSFET can be fully turned on. The output voltage is sampled through a resistor divider network (the thirty-fifth and thirty-sixth resistors) and sent to the controller's FB pin (feedback pin). The controller internally compares this voltage with a precision reference voltage. The COMP pin is connected to a compensation network consisting of the twenty-fourth capacitor, the twenty-fifth capacitor, and the twenty-ninth resistor. This network is used to adjust the frequency response of the feedback loop, ensuring that the system operates stably under all load conditions without oscillation. The SENSE+ pin, along with resistors 32, 33, and 34, forms a current sensing network. Overcurrent protection and peak current control are achieved by sensing the current in the inductor or the lower MOSFET. The ILIM pin sets the current limit threshold via resistor 37. The SS pin, through capacitor 28, enables soft-start, allowing the output voltage to rise smoothly during startup and preventing large inrush currents. Capacitor 27 and the electrolytic capacitor form an output filter at the output, further smoothing the voltage, reducing ripple, and providing clean DC power to the load.

[0041] In a preferred embodiment, the second conversion module 3 includes: a DC-DC converter, a 30th capacitor, a 31st capacitor, a 32nd capacitor, a 33rd capacitor, a 34th capacitor, a 35th capacitor, a 36th capacitor, a 37th capacitor, a 39th resistor, a 40th resistor, a 41st resistor, and a 42nd resistor; the VIN pin of the DC-DC converter is connected to one end of the 30th capacitor, one end of the 31st capacitor, and one end of the 39th resistor, respectively; the other ends of the 30th capacitor and the other ends of the 31st capacitor are both grounded; the EN pin of the DC-DC converter is connected to the other end of the 39th resistor; the LX pin of the DC-DC converter is respectively... One end of the iron-core inductor is connected to one end of the thirty-second capacitor; the BS pin of the DC-DC converter is connected to the other end of the thirty-third capacitor; one end of the fortieth resistor is connected to one end of the thirty-fourth capacitor, one end of the thirty-fifth capacitor, one end of the thirty-sixth capacitor, one end of the thirty-seventh capacitor, and one end of the forty-first resistor, respectively; the other end of the fortieth resistor is connected to the FB / OUT pin of the DC-DC converter, one end of the forty-second resistor, and the other end of the thirty-fourth capacitor, respectively; the other ends of the thirty-fifth capacitor, the thirty-sixth capacitor, the thirty-seventh capacitor, and the forty-second resistor are all grounded.

[0042] Specifically, the VIN pin is the power input terminal, receiving the DC voltage from the preceding stage. The 30th and 31st capacitors are connected in parallel to ground, forming an input decoupling and filtering network to filter out high-frequency noise and low-frequency ripple from the input power supply and provide a large instantaneous current to the chip. The EN pin is the enable pin, connected to the input voltage VIN pin via the 39th resistor. This forms a pull-up circuit, ensuring that the converter automatically starts operating once the input power supply VIN is established. This resistor also acts as a current limiter. Switching and energy conversion (LX, BS pins and inductors / capacitors): The LX pin is the switching node pin, internally integrating a power MOSFET switch. This pin is connected to the output terminal via an external iron-core inductor and the 32nd capacitor. The internal switch operates at high frequency, generating a square wave voltage at the LX pin. An LC filter composed of the iron-core inductor and the 32nd capacitor (output filter capacitor) smooths the square wave into a stable DC voltage. The BS pin is connected to the LX pin via the 33rd capacitor, which constitutes a typical bootstrap circuit to generate a drive voltage higher than the input voltage, ensuring that the NMOS power transistors in the internal upper bridge arm can be fully turned on and reducing conduction losses.

[0043] In a preferred embodiment, the system further includes: a 4G module 6, an OTG circuit 7, and a control module; the 4G module 6 includes a step-down circuit and a 4G circuit; the step-down circuit is connected to the second conversion module 3 and the 4G circuit 6 respectively; the 4G circuit is connected to the OTG circuit 7 and the control module respectively.

[0044] Specifically, the 4G module contains a step-down circuit. This circuit directly obtains power (e.g., 12V or 5V) from the second conversion module 3 and efficiently converts it into the low-voltage, high-current power required by the core of the 4G circuit (e.g., 3.8V or 3.3V).

[0045] 4G modules generate significant peak current during communication. A step-down circuit prevents large current fluctuations from interfering with the power quality of the control module in the system. It provides a fast, dynamic response to meet the instantaneous power demands of 4G communication. It confines high power loss to a localized area of ​​the 4G module, facilitating thermal management. A typical 4G circuit includes a 4G modem, power amplifier (PA), RF front-end, and SIM card interface. It accesses the internet via mobile networks (2G / 3G / 4G) to enable remote wireless data transmission. The OTG circuit provides a USB interface, allowing the device to act as a USB host, connecting peripherals such as USB flash drives and 4G network cards. The 4G module connects to the OTG circuit via the USB interface, and the OTG circuit then transmits data to the control module. This connection method offers high bandwidth, mature drivers, and is a common industry practice. The control module (usually the main processor MCU or MPU) receives and processes network data from the 4G module through the OTG circuit; simultaneously, it also uploads data to the network via the 4G module. The control module also coordinates the working logic of 4G and Ethernet communication, such as implementing network redundancy or load balancing.

[0046] In a preferred embodiment, the 4G circuit includes: a connector, a 38th capacitor, a 39th capacitor, a 40th capacitor, a 41st capacitor, a 42nd capacitor, a 43rd capacitor, a 44th capacitor, a first electrostatic discharge (ESD) protection diode, a SIM card interface, a SIM card, a first ESD suppressor, a second ESD suppressor, a third ESD suppressor, a 43rd resistor, a 44th resistor, a 45th resistor, a 46th resistor, and a 47th resistor; the 3.3V_2 pin, the +3.3Vaux pin, the 3.3V_1 pin, the Reserved4 pin, and the Reserved5 pin of the connector are each connected to one of the 38th capacitors. The connector's REFCLK- pin is connected to one end of the 40th capacitor via the 43rd resistor, and the other end of the 40th capacitor is grounded. The connector's W_DISABLE pin is connected to one end of the 45th resistor via the 44th resistor. The connector's PERST pin is connected to the other end of the 45th resistor and one end of the 46th resistor. The first pin of the first electrostatic discharge protection diode is connected to the DATA pin of the SIM card interface and the UIM_DATA pin of the connector. The third pin of the first electrostatic discharge protection diode is connected to the... The CLK pin of the SIM card interface and the UIM_CLK pin of the connector are connected; the sixth pin of the first electrostatic discharge (ESD) diode is connected to the RESET pin of the SIM card interface and the UIM_RESET pin of the connector; the fifth pin of the first ESD diode is connected to the UIM_PWR pin and the UIM_VPP pin of the connector; the DATA pin of the SIM card interface is connected to one end of the forty-seventh resistor, one end of the forty-first capacitor, one end of the first ESD suppressor, and the seventh pin of the SIM card; the other end of the forty-first capacitor and the other end of the first ESD suppressor are both grounded; the CLK pin of the SIM card interface... The VPP pin of the SIM card interface is connected to one end of the forty-second capacitor, one end of the second electrostatic discharge (ESD) suppressor, and the eighth pin of the SIM card, respectively. The other ends of the forty-second capacitor and the second ESD suppressor are both grounded. The VPP pin of the SIM card interface is connected to the other end of the forty-seventh resistor, the VCC pin of the SIM card interface, and one end of the forty-third capacitor, respectively. The other end of the forty-third capacitor is grounded. The GND1 pin of the SIM card interface is grounded. The RESET pin of the SIM card interface is connected to the ninth pin of the SIM card, one end of the forty-fourth capacitor, and one end of the third ESD suppressor, respectively. The other ends of the forty-fourth capacitor and the third ESD suppressor are both grounded.

[0047] In a preferred embodiment, the OTG circuit 7 includes: a USB interface, a second electrostatic discharge (ESD) protection diode, a second transistor, a fourth MOSFET, a forty-eighth resistor, a forty-ninth resistor, a fiftieth resistor, a fifty-first resistor, a fifty-second resistor, a fifty-third resistor, a forty-fifth capacitor, a forty-sixth capacitor, and a diode; the first pin of the USB interface is connected to the first pin of the second ESD protection diode, one end of the forty-fifth capacitor, one end of the forty-sixth capacitor, the third pin of the fourth MOSFET, and one end of the forty-eighth resistor; the second pin of the USB interface is connected to the sixth pin of the second ESD protection diode; and the third pin of the USB interface is connected to the fourth pin of the second ESD protection diode. The fourth pin of the USB interface is connected to the emitter of the second transistor through the forty-ninth resistor, and the fourth pin of the USB interface is connected to the third conversion module through the fiftieth resistor; the second pin of the fourth MOS transistor is connected to the other end of the forty-eighth resistor, one end of the fifty-first resistor, one end of the fifty-second resistor, and the cathode of the diode, respectively, and the other end of the fifty-second resistor is connected to the anode of the diode; the first pin of the fourth MOS transistor is connected to the other end of the fifty-first resistor and the collector of the second transistor, and the base of the second transistor is connected to one end of the fifty-third resistor; the other ends of the forty-fifth capacitor and the forty-sixth capacitor are both grounded.

[0048] In a preferred embodiment, there is a WiFi module circuit 8 and an ETC circuit 9; the WiFi module circuit 8 is connected to the second conversion module 3, the third conversion module 4, the ETC circuit 9 and the control module respectively; the control module is connected to the ETC circuit 9.

[0049] Specifically, the WiFi module obtains low-voltage DC power from the second conversion module 3 to ensure the normal operation of its radio frequency circuit and avoid performance degradation due to power supply noise. The WiFi module connects to the Ethernet via the third conversion module. This allows the WiFi module to act as a wireless access point (AP), transmitting data traffic from locally connected Wi-Fi clients (such as mobile phones and computers) to the Internet or a backend server via a wired network. The WiFi module connects directly to the control module, receives its instructions, and can send data (such as transaction data from ETC circuit 9) to the user terminal via the Wi-Fi network. Simultaneously, it also connects to ETC circuit 9, forming a local micro-network to achieve high-speed data interaction with ETC devices. ETC circuit 9 is the core that executes specific business logic and typically includes a dedicated IC, radio frequency front-end, antenna matching circuit, and security unit. It is responsible for 5.8GHz DSRC (Dedicated Short Range Communication) with the OBU (On-Board Unit) of passing ETC vehicles to complete identity authentication, secure transactions, and data exchange. The control module directly connects to and controls ETC circuit 9, responsible for initiating communication processes, processing transaction data, executing business logic (such as deduction and release instructions), and recording transaction logs. ETC circuit 9 transmits transaction data via WiFi module circuit 8. This allows transaction data to:

[0050] In a preferred embodiment, Bluetooth module circuit 10 and Bluetooth module circuit 18 are respectively connected to the third conversion module 4 and the control module.

[0051] Specifically, the third conversion module 4 serves as a power conversion and interface level management unit. It provides low-voltage DC power (e.g., 3.3V) to the Bluetooth module. This connection may also include signal level conversion to ensure that the Bluetooth module's logic level (typically 3.3V) can communicate correctly and safely with the control module or other circuits connected to the third conversion module (which may operate at 5V or other voltages). The Bluetooth module connects directly to the control module (main processor) via serial communication interfaces such as UART, SPI, or USB. The control module sends AT commands to the Bluetooth module for configuration and control (e.g., setting the device name and broadcast parameters). It receives data from external devices (e.g., mobile phones, sensors) transmitted by the Bluetooth module and transmits data to external devices via the Bluetooth module. The Bluetooth module circuitry integrates a Bluetooth RF chip, protocol stack, and antenna circuitry, responsible for wireless communication in the 2.4GHz ISM band, handling low-level wireless data packet transmission and reception, frequency hopping, connection management, and other tasks.

[0052] Other structures of the PoE power supply circuit described in this embodiment are available in the prior art.

[0053] The above description is merely a preferred embodiment of the present utility model and is not intended to limit the present utility model in any way. Therefore, any modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present utility model without departing from the technical solution of the present utility model shall still fall within the scope of the technical solution of the present utility model.

Claims

1. A PoE power supply circuit, characterized in that, include: The system includes a power supply module, a first conversion module, a second conversion module, a third conversion module, and an Ethernet module. The power supply module is connected to the second conversion module and the third conversion module respectively through the first conversion module; The Ethernet module is connected to the power supply module.

2. The PoE power supply circuit according to claim 1, characterized in that, The Ethernet module includes: Network transformer, first capacitor, second capacitor, third capacitor, fourth capacitor, fifth capacitor, sixth capacitor, first resistor, second resistor, third resistor, seventh capacitor, network interface and first iron core inductor; The TDC pin of the network transformer is grounded through the first capacitor; The RDC pin of the network transformer is grounded through the second capacitor; The TXN pin of the network transformer is connected to one end of the first resistor through the third capacitor, and the other end of the first resistor is connected to ground through the fifth capacitor. The RXC pin of the network transformer is connected to one end of the second resistor through the fourth capacitor, and the other end of the second resistor is connected to ground through the sixth capacitor. The TD+ pin of the network interface is connected to the TXP pin of the network transformer, and the TD- pin of the network interface is connected to the TXM pin of the network transformer. The RX+ pin of the network interface is connected to the RXP pin of the network transformer, and the RX- pin of the network interface is connected to the RXM pin of the network transformer. The G+ pin and Y+ pin of the network interface are both connected to the third conversion module through the first iron core inductor, and the G+ pin and Y+ pin of the network interface are both grounded through the seventh capacitor. Both the GND2 and GND3 pins of the network interface are grounded through the third resistor.

3. A PoE power supply circuit according to claim 2, characterized in that, The power supply module includes: First rectifier bridge, second rectifier bridge, fourth resistor, fifth resistor, first Zener diode, second Zener diode, first MOSFET, sixth resistor, eighth capacitor, seventh resistor, eighth resistor, first LED, ninth resistor, tenth resistor, third Zener diode, first transistor, eleventh resistor, ninth capacitor, tenth capacitor, twelfth resistor, thirteenth resistor, fourteenth resistor, fifteenth resistor, sixteenth resistor, seventeenth resistor, eighteenth resistor, nineteenth resistor, twentieth resistor, twenty-first resistor, eleventh capacitor, twelfth capacitor, thirteenth capacitor, fourteenth capacitor, fifteenth capacitor, sixteenth capacitor, fourth Zener diode and Ethernet power supply controller; The AC1 pin of the first rectifier bridge is connected to one end of the fourth resistor through the ninth capacitor, and the other end of the fourth resistor is grounded through the sixth resistor. The AC pin of the first rectifier bridge is connected to one end of the fifth resistor through the tenth capacitor, and the other end of the fifth resistor is grounded through the sixth resistor; The positive terminal of the first rectifier bridge is connected to the negative terminal of the first rectifier bridge through the sixth resistor; The AC1 pin of the second rectifier bridge is connected to the RXC pin of the network transformer, and the AC pin of the second rectifier bridge is connected to the TXN pin of the network transformer. The positive terminal of the second rectifier bridge is connected to the negative terminal of the second rectifier bridge through the twenty-first resistor; The seventh resistor is connected to one end of the eighth resistor, the cathode of the second Zener diode, and the first pin of the first MOSFET through the first Zener diode. One end of the seventh resistor is connected to the anode of the second rectifier bridge. The other end of the eighth resistor is connected to the positive terminal of the second Zener diode, the second pin of the first MOSFET, and the negative terminal of the second rectifier bridge, respectively, and the third pin of the first MOSFET is grounded. The AUX pin of the Power over Ethernet controller is connected to the positive terminal of the second rectifier bridge via a ninth resistor; The FTY pin of the Power over Ethernet controller is connected to the CLASS pin of the Power over Ethernet controller through the tenth resistor. The AUX pin of the Power over Ethernet controller is connected to one end of the eleventh capacitor, the positive terminal of the third Zener diode, the VSS pin of the Power over Ethernet controller, and the VSS1 pin of the Power over Ethernet controller, respectively. The other end of the eleventh capacitor is connected to the negative terminal of the third Zener diode and one end of the eleventh resistor, respectively. The other end of the eleventh resistor is connected to the EN pin of the Power over Ethernet controller and the PG pin of the Power over Ethernet controller, respectively. The T2P pin of the Ethernet power controller is connected to the negative terminal of the first light-emitting diode, and the positive terminal of the first light-emitting diode is connected to one end of the eleventh resistor through the twelfth resistor. The DET pin of the Power over Ethernet controller is connected to one end of the eleventh resistor through the twelfth resistor; One end of the thirteenth resistor is connected to one end of the fourteenth resistor and one end of the eleventh resistor, respectively, and the other end of the thirteenth resistor is connected to the negative terminal of the fourth Zener diode and the base of the first transistor, respectively. The emitter of the first transistor is connected to the VIN pin of the Ethernet power supply controller, and the collector of the first transistor is connected to the other end of the fourteenth resistor. The NC5, NC6, and NC7 pins of the Power over Ethernet (PoE) controller are all connected to the VIN pin of the PoE controller via the twelfth capacitor and are grounded. The GATE pin of the Power over Ethernet controller is grounded through the thirteenth capacitor; The ISENS pin of the Ethernet power controller is connected to one end of the fifteenth resistor and one end of the sixteenth resistor, respectively. The other end of the sixteenth resistor is connected to one end of the seventeenth resistor and one end of the eighteenth resistor, respectively. The other ends of the seventeenth resistor and the eighteenth resistor are both grounded. The FB pin of the Power over Ethernet controller is grounded through the nineteenth resistor; The COMP pin of the Power over Ethernet controller is grounded through the fourteen capacitors; The VCC pin of the Ethernet power controller is connected to the other end of the fifteenth resistor and one end of the fifteenth capacitor, respectively, and the other end of the fifteenth capacitor is grounded. The SS pin of the Power over Ethernet controller is grounded through the sixteenth capacitor; The RT pin of the Power over Ethernet controller is grounded through the twentieth resistor; The RTN pin, RTN1 pin, GND1 pin, GND pin, NC1 pin, NC2 pin, NC3 pin, and NC4 pin of the Power over Ethernet (PoE) controller are all grounded.

4. A PoE power supply circuit according to claim 3, characterized in that, The first conversion module includes: First inductor, electrolytic capacitor, third rectifier bridge, seventeenth capacitor, eighteenth capacitor, nineteenth capacitor, step-down controller, twentieth capacitor, twenty-second resistor, twenty-third resistor, twenty-fourth resistor, twenty-fifth resistor, twenty-sixth resistor, twenty-seventh resistor, twenty-eighth resistor, twenty-ninth resistor, twenty-first capacitor, twenty-second capacitor, twenty-third capacitor, twenty-fourth capacitor, twenty-fifth capacitor, twenty-sixth capacitor, second MOSFET, third MOSFET, thirtieth resistor, thirty-first resistor, thirty-second resistor, thirty-third resistor, thirty-fourth resistor, thirty-fifth resistor, thirty-sixth resistor, thirty-seventh resistor, thirty-eighth resistor, twenty-seventh capacitor, twenty-eighth capacitor, and twenty-ninth capacitor; The AC1 pin of the third rectifier bridge is connected to the AC1 pin of the first rectifier bridge, the AC pin of the third rectifier bridge is connected to the AC pin of the first rectifier bridge, the positive terminal of the third rectifier bridge is connected to one end of the seventeenth capacitor, one end of the eighteenth capacitor and one end of the nineteenth capacitor respectively, and the other ends of the seventeenth capacitor, the eighteenth capacitor and the nineteenth capacitor are all grounded. The IN pin of the buck controller is grounded through the nineteenth capacitor; The FREQ pin of the buck controller is grounded through the 22nd resistor; The PG pin of the buck controller is connected to the VCC1 pin of the buck controller through the 23rd resistor, and the VCC1 pin of the buck controller is grounded through the 20th capacitor; The VCC2 pin of the buck controller outputs a 12V voltage through the twenty-fourth resistor, and the VCC2 pin of the buck controller is grounded through the twenty-first capacitor; The SYNCO pin of the buck controller is grounded through the 25th resistor; The EN / SYNC pin of the buck controller is connected to the positive terminal of the second rectifier bridge through the second sixteenth resistor, the EN / SYNC pin of the buck controller is grounded through the second seventeenth resistor, and the EN / SYNC pin of the buck controller is grounded through the second twenty-second capacitor; The CCM / AAM pin of the buck controller is connected to one end of the 23rd capacitor and one end of the 28th resistor, respectively, and the other end of the 23rd capacitor and the other end of the 28th resistor are both grounded; The COMP pin of the buck controller is connected to one end of the 24th capacitor and one end of the 25th capacitor respectively. The other end of the 24th capacitor is connected to the other end of the 25th capacitor through the 29th resistor. The other end of the 25th capacitor is grounded. The BST pin of the buck controller is connected to one end of the 26th capacitor through the 30th resistor, and the other end of the 26th capacitor is connected to the SW pin of the buck controller, one end of the first inductor, and one end of the 31st resistor. The SENSE+ pin of the buck controller is connected to the other end of the first inductor and one end of the thirty-third resistor through the thirty-second resistor; The SENSE+ pin of the buck controller is connected to the other end of the thirty-third resistor, the positive terminal of the electrolytic capacitor, and one end of the twenty-seventh capacitor through the thirty-fourth resistor. The negative terminal of the electrolytic capacitor and the other end of the twenty-seventh capacitor are both grounded. The FB pin of the buck controller is connected to the other end of the 33rd resistor through the 35th resistor, and the FB pin of the buck controller is grounded through the 36th resistor; The ILIM pin of the buck controller is grounded through the thirty-seventh resistor; The SS pin of the buck controller is grounded through the 28th capacitor; The fourth pin of the second MOSFET is connected to the TG pin of the buck controller, and the first pin, the second pin, and the third pin of the second MOSFET are all connected to the SW pin of the buck controller. The fourth pin of the third MOSFET is connected to the BG pin of the buck controller through the thirty-eighth resistor. The fifth, sixth, seventh, eighth and ninth pins of the third MOSFET are all connected to one end of the first inductor. One end of the 29th capacitor is connected to the other end of the 31st resistor, and the other end of the 29th capacitor is grounded.

5. A PoE power supply circuit according to claim 4, characterized in that, The second conversion module includes: DC-DC converter, 30th capacitor, 31st capacitor, 32nd capacitor, 33rd capacitor, 34th capacitor, 35th capacitor, 36th capacitor, 37th capacitor, 39th resistor, 40th resistor, 41st resistor and 42nd resistor; The VIN pin of the DC-DC converter is connected to one end of the 30th capacitor, one end of the 31st capacitor, and one end of the 39th resistor, respectively. The other ends of the 30th capacitor and the 31st capacitor are both grounded. The EN pin of the DC-DC converter is connected to the other end of the thirty-ninth resistor; The LX pin of the DC-DC converter is connected to one end of the iron core inductor and one end of the thirty-second capacitor, respectively. The BS pin of the DC-DC converter is connected to the other end of the thirty-third capacitor; One end of the fortieth resistor is connected to one end of the thirty-fourth capacitor, one end of the thirty-fifth capacitor, one end of the thirty-sixth capacitor, one end of the thirty-seventh capacitor, and one end of the fortieth resistor, respectively. The other end of the fortieth resistor is connected to the FB / OUT pin of the DC-DC converter, one end of the forty-second resistor, and the other end of the thirty-fourth capacitor, respectively. The other ends of the thirty-fifth capacitor, the thirty-sixth capacitor, the thirty-seventh capacitor, and the forty-second resistor are all grounded.

6. A PoE power supply circuit according to claim 5, characterized in that, Also includes: 4G module, OTG circuit and control module; The 4G module includes a step-down circuit and a 4G circuit. The step-down circuit is connected to the second conversion module and the 4G circuit respectively; The 4G circuit is connected to the OTG circuit and the control module respectively.

7. A PoE power supply circuit according to claim 6, characterized in that, The 4G circuit includes: Connector, capacitor number 38, capacitor number 39, capacitor number 40, capacitor number 41, capacitor number 42, capacitor number 43, capacitor number 44, first electrostatic discharge protection diode, SIM card interface, SIM card, first electrostatic discharge suppressor, second electrostatic discharge suppressor, third electrostatic discharge suppressor, resistor number 43, resistor number 44, resistor number 45, resistor number 46 and resistor number 47; The 3.3V_2 pin, the +3.3Vaux pin, the 3.3V_1 pin, the Reserved4 pin, and the Reserved5 pin of the connector are all connected to one end of the thirty-eighth capacitor and one end of the thirty-ninth capacitor, respectively. The other ends of the thirty-eighth capacitor and the other ends of the thirty-ninth capacitor are both grounded. The REFCLK- pin of the connector is connected to one end of the fortieth capacitor through the forty-third resistor, and the other end of the fortieth capacitor is grounded; The W_DISABLE pin of the connector is connected to one end of the forty-fifth resistor through the forty-fourth resistor; The PERST pin of the connector is connected to the other end of the forty-fifth resistor and one end of the forty-sixth resistor, respectively. The first pin of the first electrostatic protection diode is connected to the DATA pin of the SIM card interface and the UIM_DATA pin of the connector, respectively. The third pin of the first electrostatic protection diode is connected to the CLK pin of the SIM card interface and the UIM_CLK pin of the connector, respectively; The sixth pin of the first electrostatic protection diode is connected to the RESET pin of the SIM card interface and the UIM_RESET pin of the connector, respectively; The fifth pin of the first electrostatic protection diode is connected to the UIM_PWR pin of the connector and the UIM_VPP pin of the connector, respectively. The DATA pin of the SIM card interface is connected to one end of the forty-seventh resistor, one end of the forty-first capacitor, one end of the first electrostatic suppressor, and the seventh pin of the SIM card, respectively. The other end of the forty-first capacitor and the other end of the first electrostatic suppressor are both grounded. The CLK pin of the SIM card interface is connected to one end of the forty-second capacitor, one end of the second electrostatic suppressor, and the eighth pin of the SIM card, respectively. The other end of the forty-second capacitor and the other end of the second electrostatic suppressor are both grounded. The VPP pin of the SIM card interface is connected to the other end of the forty-seventh resistor, the VCC pin of the SIM card interface, and one end of the forty-third capacitor, respectively. The other end of the forty-third capacitor is grounded. The GND1 pin of the SIM card interface is grounded; The RESET pin of the SIM card interface is connected to the ninth pin of the SIM card, one end of the forty-fourth capacitor, and one end of the third electrostatic discharge suppressor, respectively. The other end of the forty-fourth capacitor and the other end of the third electrostatic discharge suppressor are both grounded.

8. A PoE power supply circuit according to claim 7, characterized in that, The OTG circuit includes: USB interface, second electrostatic protection diode, second transistor, fourth MOSFET, forty-eighth resistor, forty-ninth resistor, fiftieth resistor, fifty-first resistor, fifty-second resistor, fifty-third resistor, forty-fifth capacitor, forty-sixth capacitor and diode; The first pin of the USB interface is connected to the first pin of the second electrostatic protection diode, one end of the forty-fifth capacitor, one end of the forty-sixth capacitor, the third pin of the fourth MOSFET, and one end of the forty-eighth resistor, respectively. The second pin of the USB interface is connected to the sixth pin of the second electrostatic protection diode; The third pin of the USB interface is connected to the fourth pin of the second electrostatic protection diode. The fourth pin of the USB interface is connected to the emitter of the second transistor through the forty-ninth resistor, and the fourth pin of the USB interface is connected to the third conversion module through the fiftieth resistor. The second pin of the fourth MOS transistor is connected to the other end of the forty-eighth resistor, one end of the fifty-first resistor, one end of the fifty-second resistor, and the negative terminal of the diode, respectively. The other end of the fifty-second resistor is connected to the positive terminal of the diode. The first pin of the fourth MOS transistor is connected to the other end of the fifty-first resistor and the collector of the second transistor, respectively, and the base of the second transistor is connected to one end of the fifty-third resistor; The other end of the forty-fifth capacitor and the other end of the forty-sixth capacitor are both grounded.

9. A PoE power supply circuit according to claim 8, characterized in that, include: WiFi module circuit and ETC circuit; The WiFi module circuit is connected to the second conversion module, the third conversion module, the ETC circuit, and the control module, respectively; The control module is connected to the ETC circuit.

10. A PoE power supply circuit according to claim 9, characterized in that, include: A Bluetooth module circuit is provided, which is connected to the third conversion module and the control module respectively.

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