CN205160395U - POE receives electric control circuit and POE power supply system - Google Patents

Abstract

The utility model is applicable to the field of POE power supply, and provides a POE power receiving control circuit and a POE power supply system. connection; the power receiving control unit, its forward and reverse power supply terminals are respectively connected to the forward and reverse output terminals of the first polarity determination unit, and its output terminal is connected to the powered equipment; the power expansion unit, its first input terminal is connected to the The positive power supply terminal of the power receiving control unit is connected, the second input terminal thereof is connected with the load terminal of the power receiving control unit, and the output terminal thereof is connected with the reverse power supply terminal of the power receiving control unit. The utility model expands the range of received power by generating auxiliary current through the power expansion unit, and solves the problem that the received power of the existing POE power supply standard is too small to meet the application of high-power flashlight equipment.

Description

A POE power receiving control circuit and POE power supply system

technical field

The utility model belongs to the field of POE power supply, in particular to a POE power receiving control circuit and a POE power supply system.

Background technique

At present, the POE power supply system is developing rapidly with the rapid popularization of the network. POE (PoweroverEthernet), generally known as Power over Ethernet technology in Chinese, refers to the existing Ethernet Cat.5 wiring infrastructure without any changes. Under certain circumstances, while transmitting data signals for some IP-based terminal equipment, it can also provide electric power for such equipment, including PSE (PowerSourcingEquipment, power supply equipment) and PD (PoweredDevice, powered device). For network communication equipment, POE power supply means reducing a power supply line, which has the characteristics of simple use, low cost, high reliability, safety and simple control, and has great benefits for engineering construction wiring.

However, for the current POE power supply standard 802.3af, the power received by the PD terminal is only 12.95W. For the higher power POE power supply standard 802.3at, the power received by the PD terminal is only 25W. The existing PD handshake chips are also in accordance with It is designed according to the POE power supply standard, and its power generally only meets the 25W standard of 802.3at. For ordinary Internet phones, video phones, low-power high-definition video surveillance systems and small switches, the power is sufficient for their work, but for Some high-power equipment, such as personal computers, PTZ (PanTiltZoom, pan-tilt omni-directional (left/right/up and down) movement and lens zoom, zoom control) functions of high-definition video surveillance systems and other equipment, its power cannot guarantee its normal work.

Utility model content

The purpose of the embodiment of the utility model is to provide a POE power receiving control circuit, aiming at solving the problem that the power receiving power of the existing POE power supply standard is too small to meet the application of high-power flashlight equipment.

The embodiment of the utility model is realized in this way. A POE power receiving control circuit is connected between the power supply equipment unit and the power receiving equipment. The circuit includes:

After completing the handshake protocol, determine the power supply polarity output by the power supply equipment unit in the power supply stage, and generate the first polarity determination unit of the DC power supply voltage, the first and second input terminals of the first polarity determination unit Both are connected to the output end of the power supply unit;

A power receiving control unit that implements a handshake protocol with the power supply equipment unit and outputs received power according to the DC power supply voltage during the power supply phase, the forward power supply terminal of the power receiving control unit is connected to the first polarity determining unit connected to the positive output terminal, the reverse power supply terminal of the power receiving control unit is connected to the reverse output terminal of the first polarity determination unit, and the output terminal of the power receiving control unit is connected to the powered device;

A power expansion unit that expands the range of the received power by generating an auxiliary current, the first input terminal of the power expansion unit is connected to the positive power supply terminal of the power reception control unit, and the second input of the power expansion unit The terminal is connected to the load terminal of the power receiving control unit, and the output terminal of the power expansion unit is connected to the reverse power supply terminal of the power receiving control unit.

Further, the first polarity determination unit is a rectifier bridge, the first terminal and the third terminal of the rectifier bridge are respectively the first and second input terminals of the first polarity determination unit, and the rectifier bridge The second terminal and the fourth terminal of are respectively the forward and reverse output terminals of the first polarity determination unit.

Further, the circuit also includes:

A second polarity determination unit, the first and second input terminals of the second polarity determination unit are both connected to the output terminal of the power supply unit, and the forward and reverse output terminals of the second polarity determination unit They are respectively connected to the forward and reverse power supply terminals of the power receiving control unit.

Further, the power receiving control unit includes:

Resistor R1, resistor R4, resistor R5, resistor R6, resistor R7, capacitor C1 and power receiving control chip;

The ILIM pin of the power receiving control chip is connected to one end of the resistor R6, the CLASS pin of the power receiving control chip is connected to one end of the resistor R5, the other end of the resistor R5, the resistor R6 The other end of both is the reverse power supply end of the power receiving control unit, the DET pin of the power receiving control chip is connected to one end of the resistor R4, and the other end of the resistor R4 is the power receiving control unit The positive power supply terminal of the power receiving control chip is the reverse power supply terminal of the power receiving control unit, the RTN pin of the power receiving control chip is the load terminal of the power receiving control unit, The PG pin of the power receiving control chip is the output end of the power receiving control unit, and the UVLO pin of the power receiving control chip is connected to one end of the resistor R7 and one end of the resistor R1 at the same time, and the The other end of the resistor R7 is the positive power supply end of the power receiving control unit, the other end of the resistor R1 is connected to the PWPd pin of the power receiving control chip, and the PWPd pin of the power receiving control chip is the terminal of the power receiving control chip. The reverse power supply terminal of the power receiving control unit, the VDD pin of the power receiving control chip is the forward power supply terminal of the power receiving control unit, and the two ends of the capacitor C1 are respectively the terminals of the power receiving control unit. Forward and reverse power terminals.

Further, the power expansion unit includes:

Resistor R2, capacitor C2 and a second switch tube;

One end of the capacitor C2 is the first input end of the power expansion unit, the other end of the capacitor C2 is grounded and connected to one end of the resistor R2, and the other end of the resistor R2 is the first input end of the power expansion unit. The second input terminal is connected to the control terminal of the second switching tube, the input terminal of the second switching tube is grounded, and the output terminal of the second switching tube is the output terminal of the power expansion unit.

Furthermore, the second switch transistor is a PNP transistor, the base of the PNP transistor is the control terminal of the second switch transistor, and the emitter of the PNP transistor is the input terminal of the second switch transistor. , the collector of the PNP transistor is the output end of the second switching transistor.

Furthermore, the flow capacity of the second switch tube and the parameters of the matched resistor R2 determine the output received power range.

Further, the power expansion unit also includes:

Resistor R3 and the first switch tube;

The resistor R3 is connected between the input terminal of the second switch tube and the ground terminal, the control terminal of the first switch tube is connected to the input terminal of the second switch tube, and the input terminal of the first switch tube The end is connected to one end of the resistor R2, the input end of the first switch tube is also grounded, and the output end of the first switch tube is connected to the other end of the resistor R2.

Furthermore, the first switch transistor is a PNP transistor, the base of the PNP transistor is the control terminal of the first switch transistor, and the emitter of the PNP transistor is the input terminal of the first switch transistor. , the collector of the PNP transistor is the output end of the first switching transistor.

Another object of the embodiments of the present invention is to provide a POE power supply system, including a power supply device unit and a power receiving device unit including the above-mentioned POE power receiving control circuit.

The embodiment of the utility model is based on the standard protocol of the PD end of the POE power supply system, and the auxiliary current is generated by the power expansion unit to expand the range of the received power, which can realize the POE power supply transmission of any received power, and solve the problem of the received power of the existing POE power supply standard Too small to meet the problem of high-power flashlight equipment applications.

Description of drawings

Fig. 1 is a structural diagram of the POE power receiving control circuit provided by the embodiment of the present invention;

Fig. 2 is an example circuit structure of a POE power receiving control circuit based on the POE power supply standard 802.3af provided by the embodiment of the present invention;

FIG. 3 is an internal structural diagram of the power receiving control chip;

Fig. 4 is an example circuit structure of a POE power receiving control circuit based on the POE power supply standard 802.3at provided by the embodiment of the present invention.

detailed description

In order to make the purpose, technical solution and advantages of the utility model clearer, the utility model will be further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described here are only used to explain the utility model, and are not intended to limit the utility model. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not constitute conflicts with each other.

The embodiment of the utility model is based on the standard protocol of the PD end of the POE power supply system, and the auxiliary current is generated by the power expansion unit to expand the range of the received power, so as to solve the problem that the received power of the existing POE power supply standard is too small to meet the application of high-power flashlight equipment The problem.

Fig. 1 shows the structure of the POE power receiving control circuit provided by the embodiment of the present invention. For the convenience of description, only the parts related to the present invention are shown.

As an embodiment of the present invention, the POE power receiving control circuit 1 is connected between the power supply equipment (PSE) unit 2 and the power receiving equipment 3, and can be applied to any POE power supply system, including:

The first polarity determination unit 11 is used to determine the polarity of the power supply output by the power supply equipment unit in the power supply stage after completing the handshake protocol, and generate a DC power supply voltage V _DD , the first and second polarity of the first polarity determination unit 11 The input terminals are all connected to the output terminals of the power supply equipment (PSE) unit 2;

The power receiving control unit 12 is used to implement the handshake protocol with the power supply equipment unit 2, and output the power received power PowerGood according to the DC power supply voltage V _DD in the power supply stage, and the forward power supply terminal of the power receiving control unit 12 is connected to the first polarity determination unit 11 The positive output end of the power receiving control unit 12 is connected to the reverse power supply end of the first polarity determination unit 11, and the output end of the power receiving control unit 12 is connected to the powered device;

The power expansion unit 13 is used to expand the range of the received power by generating auxiliary current, the first input terminal of the power expansion unit 13 is connected to the positive power supply terminal of the power receiving control unit 12, and the second input terminal of the power expansion unit 13 is connected to The load terminal of the power receiving control unit 12 is connected, and the output terminal of the power expansion unit 13 is connected with the reverse power supply terminal of the power receiving control unit 12 .

In the embodiment of the utility model, the power supply equipment (PSE) unit 2 includes the power supply equipment and its necessary control circuit, and the power receiving equipment 3 can be a low-power power receiving equipment such as a video phone, a small switch, or a personal computer, a PTZ Functional high-definition video surveillance system and other high-power powered equipment.

The embodiment of the utility model is based on the standard protocol of the PD end of the POE power supply system, and the auxiliary current is generated by the power expansion unit to expand the range of the received power, so as to solve the problem that the received power of the existing POE power supply standard is too small to meet the application of high-power flashlight equipment The problem.

It will be described in detail below through specific examples.

FIG. 2 is an example circuit structure of a POE power receiving control circuit based on the POE power supply standard 802.3af. For the convenience of description, only the parts related to the present invention are shown.

As an embodiment of the present invention, the first polarity determination unit 11 can be realized by a rectifier bridge, the first end and the third end of the rectification bridge are respectively the first and second input ends of the first polarity determination unit 11, The second terminal and the fourth terminal of the rectifier bridge are respectively the positive and negative output terminals of the first polarity determining unit 11 .

The power receiving control unit 12 includes:

Resistor R1, resistor R4, resistor R5, resistor R6, resistor R7, capacitor C1 and power receiving control chip U1;

The ILIM pin of the power receiving control chip U1 is connected to one end of the resistor R6, the CLASS pin of the power receiving control chip U1 is connected to one end of the resistor R5, and the other end of the resistor R5 and the other end of the resistor R6 are the power receiving control unit 12 The reverse power supply terminal of the power receiving control chip U1 is connected to one end of the resistor R4, the other end of the resistor R4 is the positive power supply terminal of the power receiving control unit 12, the VSS pin of the power receiving control chip U1 is the receiving The reverse power supply end of the power control unit 12, the RTN pin of the power receiving control chip U1 is the load end of the power receiving control unit 12, the PG pin of the power receiving control chip U1 is the output end of the power receiving control unit 12, and the power receiving control chip U1 is the output end of the power receiving control unit 12. The UVLO pin of the control chip U1 is connected to one end of the resistor R7 and one end of the resistor R1 at the same time, the other end of the resistor R7 is the positive power supply end of the power receiving control unit 12, and the other end of the resistor R1 is connected to the PWPd of the power receiving control chip U1 pin connection, the PWPd pin of the power receiving control chip U1 is the reverse power supply end of the power receiving control unit 12, the VDD pin of the power receiving control chip U1 is the positive power supply end of the power receiving control unit 12, and the two terminals of the capacitor C1 The terminals are the forward and reverse power supply terminals of the power receiving control unit 12 respectively.

The functions of each pin of the power receiving control chip U1 are as follows:

ILIM Instantaneous current limit at start-up, set limit current size by external resistor CLASS POE system power size control, set the POE system power level through an external resistor DET Enable the chip to work VSS The chip corresponds to the current return line of the source terminal (PSE terminal) RTN The chip corresponds to the current return line of the load terminal PG POE system handshake success signal interface UVLO Minimum starting voltage setting interface

VDD Source end (PSE end) power input port

In the embodiment of the utility model, the power receiving control chip U1 completes the handshake protocol with the power supply equipment (PSE) unit 2. After the handshake is completed, the power supply equipment (PSE) unit 2 outputs power to the input terminals POE12 and POE36, and the rectifier bridge After the polarity is determined, the positive and negative output terminals of the first polarity determination unit 11 output a DC power supply voltage V _DD of 48V. At this time, the MOS transistor under the power receiving control chip U1 will be turned on, as shown in FIG. 3 , the current The current flows through the two MOS tubes inside the power receiving control chip U1. If the power expansion unit 13 is not added at this time, the maximum flow rate of the MOS tube and the overcurrent protection mechanism of the MOS tube determine the maximum power received at this time. Since the MOS tube is packaged inside the chip, its maximum flow rate is fixed by the chip manufacturer and cannot be changed by the user. Therefore, the application generates auxiliary current by setting the power expansion unit 13, thereby expanding the range of received power.

The power expansion unit 13 includes:

Resistor R2, capacitor C2 and second switch tube Q2;

One end of the capacitor C2 is the first input end of the power expansion unit 13, the other end of the capacitor C2 is grounded and connected to one end of the resistor R2, and the other end of the resistor R2 is the second input end of the power expansion unit 13 and the second switch tube Q2 The control terminal of the second switching tube Q2 is connected to the ground, and the output terminal of the second switching tube Q2 is the output terminal of the power expansion unit 13 .

As a preferred embodiment of the present invention, the second switch tube Q2 is a PNP transistor, the base of the PNP transistor is the control terminal of the second switch tube Q2, the emitter of the PNP transistor is the input terminal of the second switch tube Q2, and the PNP transistor The collector of the type triode is the output terminal of the second switching tube Q2.

In the embodiment of the present invention, the power expansion unit 13 is composed of a second switch tube Q2, a resistor R2, and a capacitor C2 to form an external switch system. When the input terminal of the first polarity determination unit 11 (ie, the PD terminal) is connected to the POE power supply system, the power receiving control chip U1 completes the handshake protocol with the power supply equipment (PSE) unit 2. After the handshake is completed, the capacitor C2 is charged. When the load current is less than 600mA, a voltage less than 0.6V will be generated at both ends of the resistor R2. At this time, the second switch tube Q2 remains in the off state, the MOS inside the power receiving control chip U1 is turned on, and the current flows from the MOS tube inside the chip. back to the front end (that is, the inverting output end of the first polarity determining unit 11).

When the load current is greater than 600mA, if there is no power expansion unit 13, the chip will enter the overcurrent state, and the overcurrent protection system of the chip will control the chip to stop working, and then cannot output the received power. However, the embodiment of the utility model is provided with power expansion After the unit 13, after the current flowing through the resistor R2 exceeds 600mA, a voltage drop of 0.6V is generated at both ends of the resistor R2. At this time, a voltage drop of 0.6V has also occurred between the CE poles of the second switching tube Q2 (assuming that the second switching tube Q2 The conduction voltage of the CE pole of Q2 is 0.6V), the second switch tube Q2 starts to conduct, then, the current exceeding 600mA flows from the resistor R3 to the second switch tube Q2 and then to the front end (that is, the reverse side of the first polarity determining unit 11 to the output).

At this time, the maximum current I _TO that the POE receiving control circuit can pass is:

I _TO =I _RTN +I _Q2

Wherein, I _RTN is the maximum current that the power receiving control chip U1 can pass, and I _Q2 is the maximum current that the power expansion unit 13 can pass.

In the embodiment of the utility model, the power received by the entire POE power supply system can be changed by selecting switch tubes with different flow rates and matching resistors, while the parameters of other circuits and components do not need to be changed with different powers. Moreover, the embodiment of the present utility model can realize POE power supply transmission of any power in theory, but in fact, the maximum received power is limited by the impedance of the transmission line.

It is worth noting that the embodiment of the present invention can be used in cooperation with any PD handshake chip (ie power receiving control chip).

The embodiment of the utility model is based on the standard protocol of the PD end of the POE power supply system, and the auxiliary current is generated by the power expansion unit to expand the range of the received power, which can realize the POE power supply transmission of any received power, and solve the problem of the received power of the existing POE power supply standard Too small to meet the problem of high-power flashlight equipment applications.

FIG. 4 is an example circuit structure of a POE power receiving control circuit based on the POE power supply standard 802.3at. For the convenience of illustration, only the parts related to the present invention are shown.

As an embodiment of the present utility model, the POE power receiving control circuit further includes:

The second polarity determination unit 14, the first input terminal POE45 and the second output terminal POE78 of the second polarity determination unit 14 are all connected with the output end of the power supply equipment (PSE) unit 2, the positive polarity of the second polarity determination unit 14 The positive and reverse output terminals are respectively connected to the forward and reverse power supply terminals of the power receiving control unit 12 .

As an embodiment of the present invention, the power expansion unit 13 also includes:

Resistor R3 and first switch tube Q1;

The resistor R3 is connected between the input terminal of the second switching tube Q2 and the ground terminal, the control terminal of the first switching tube Q1 is connected to the input terminal of the second switching tube Q2, and the input terminal of the first switching tube Q1 is connected to one end of the resistor R2 The input end of the first switching transistor Q1 is also grounded, and the output end of the first switching transistor Q1 is connected to the other end of the resistor R2.

As a preferred embodiment of the present invention, the first switch tube Q1 is a PNP transistor, the base of the PNP transistor is the control terminal of the first switch tube Q1, the emitter of the PNP transistor is the input terminal of the first switch tube Q1, and the PNP transistor The collector of the type triode is the output terminal of the first switching tube Q1.

In the embodiment of the present utility model, the protection circuit composed of the resistor R3 and the first switch tube Q1, when the voltage reflected by the current passing through the second switch tube Q2 on the resistor R3 exceeds 0.6V, the second switch tube Q2 is turned on, The first switching tube Q1 is turned off, the power expansion unit 13 stops working, and enters an over-current protection state, so as to prevent the second switching tube Q2 from being burned due to excessive current.

Another object of the embodiments of the present utility model is to provide a POE power supply system, the POE power supply system includes a power supply device unit and a power receiving device unit, wherein the power receiving device unit includes the POE power receiving control circuit in the above embodiment.

The embodiment of the utility model is based on the standard protocol of the PD end of the POE power supply system, and the auxiliary current is generated by the power expansion unit to expand the range of the received power, which can realize the POE power supply transmission of any received power, and solve the problem of the received power of the existing POE power supply standard Too small to meet the problem of high-power flashlight equipment applications.

The above are only preferred embodiments of the present utility model, and are not intended to limit the present utility model. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present utility model should be included in the utility model. within the scope of protection.

Claims (10)

1. POE is by an electric control circuit, and be connected between power supply unit unit and power receiving equipment, it is characterized in that, described circuit comprises:

After completing Handshake Protocol, the electric power polarity that described power supply unit unit exports is determined at powering phase, and generating the first polarity determining unit of direct current power source voltage, first, second input of described first polarity determining unit is all connected with the output of described power supply unit unit;

Handshake Protocol is realized with described power supply unit unit, and powering phase according to described direct current power source voltage export by electrical power by electric control unit, the described forward power end by electric control unit is connected with the forward output of described first polarity determining unit, the described reverse electrical source end by electric control unit is connected with the inverse output terminal of described first polarity determining unit, and the described output by electric control unit is connected with described power receiving equipment;

The power expansion unit of the described scope by electrical power is expanded by generating auxiliary current, the first input end of described power expansion unit is connected with the described forward power end by electric control unit, second input of described power expansion unit is connected with the described load end by electric control unit, and the output of described power expansion unit is connected with the described reverse electrical source end by electric control unit.

2. circuit as claimed in claim 1, it is characterized in that, described first polarity determining unit is rectifier bridge, the first end of described rectifier bridge and the 3rd end are respectively first, second input of described first polarity determining unit, and the second end of described rectifier bridge and the 4th end are respectively the forward and reverse output of described first polarity determining unit.

3. circuit as claimed in claim 1, it is characterized in that, described circuit also comprises:

Second polarity determining unit, first, second input of described second polarity determining unit is all connected with the output of described power supply unit unit, and the forward and reverse output of described second polarity determining unit is connected with the described forward and reverse power end by electric control unit respectively.

4. circuit as claimed in claim 1, is characterized in that, describedly comprises by electric control unit:

Resistance R1, resistance R4, resistance R5, resistance R6, resistance R7, electric capacity C1 and powered control chip;

The ILIM pin of described powered control chip is connected with one end of described resistance R6, the CLASS pin of described powered control chip is connected with one end of described resistance R5, the other end of described resistance R5, the other end of described resistance R6 is the described reverse electrical source end by electric control unit, the DET pin of described powered control chip is connected with one end of described resistance R4, the other end of described resistance R4 is the described forward power end by electric control unit, the VSS pin of described powered control chip is the described reverse electrical source end by electric control unit, the RTN pin of described powered control chip is the described load end by electric control unit, the PG pin of described powered control chip is the described output by electric control unit, the UVLO pin of described powered control chip is connected with one end of described resistance R7 and one end of described resistance R1 simultaneously, the other end of described resistance R7 is the described forward power end by electric control unit, the other end of described resistance R1 is connected with the PWPd pin of described powered control chip, the PWPd pin of described powered control chip is the described reverse electrical source end by electric control unit, the VDD pin of described powered control chip is the described forward power end by electric control unit, the two ends of described electric capacity C1 are respectively described and are just being subject to electric control unit, reverse electrical source end.

5. circuit as claimed in claim 1, it is characterized in that, described power expansion unit comprises:

Resistance R2, electric capacity C2 and second switch pipe;

One end of described electric capacity C2 is the first input end of described power expansion unit, the other end ground connection of described electric capacity C2 is also connected with one end of described resistance R2, the other end of described resistance R2 is that the second input of described power expansion unit is connected with the control end of described second switch pipe, the input end grounding of described second switch pipe, the output of described second switch pipe is the output of described power expansion unit.

6. circuit as claimed in claim 5, it is characterized in that, described second switch pipe is PNP type triode, the base stage of described PNP type triode is the control end of described second switch pipe, the input of the very described second switch pipe of transmitting of described PNP type triode, the output of the very described second switch pipe of current collection of described PNP type triode.

7. circuit as claimed in claim 5, is characterized in that, the parameter of the through-current capacity of described second switch pipe and the resistance R2 of coupling determine to export by electric power range.

8. circuit as claimed in claim 5, it is characterized in that, described power expansion unit also comprises:

Resistance R3 and the first switching tube;

Between the input that described resistance R3 is connected to described second switch pipe and earth terminal, the control end of described first switching tube is connected with the input of described second switch pipe, the input of described first switching tube is connected with one end of described resistance R2, the input also ground connection of described first switching tube, the output of described first switching tube is connected with the other end of described resistance R2.

9. circuit as claimed in claim 8, it is characterized in that, described first switching tube is PNP type triode, the base stage of described PNP type triode is the control end of described first switching tube, the input of very described first switching tube of transmitting of described PNP type triode, the output of very described first switching tube of current collection of described PNP type triode.

10. a POE electric power system, comprises power supply unit unit and power receiving equipment unit, it is characterized in that, the POE that described power receiving equipment unit comprises as described in any one of claim 1 to 9 is subject to electric control circuit.