CN-122001696-A - Ethernet power supply, voltage reduction control circuit and control method thereof

CN122001696ACN 122001696 ACN122001696 ACN 122001696ACN-122001696-A

Abstract

An Ethernet power supply is used for coupling with load equipment and comprises a power supply device, an output control circuit, a path control circuit and a control module. When the output control circuit detects that the load device is not coupled with the output end of the Ethernet power supply, the path control circuit breaks a power supply path from the output end to the control module, and the output control circuit adjusts the output voltage to a first voltage so as to enable the control module to enter a disabled state. When the output control circuit detects that the load device is coupled to the output end, the path control circuit shorts the power supply path, and the output control circuit adjusts the output voltage to the second voltage so as to enable the control module to enter an enabling state. The disclosure also relates to a buck control circuit and a control method of an Ethernet power supply.

Inventors

DU GUANXIAN
LI ZHENGJIE
LIU CHENGEN
Lin Xuanchen

Assignees

台达电子工业股份有限公司

Dates

Publication Date: 20260508
Application Date: 20241104

Claims (16)

1. An ethernet power supply for coupling to a load device, the ethernet power supply comprising: a power supply device for converting an input voltage into an output voltage and providing the output voltage to the load device via an output terminal; An output control circuit coupled to the output terminal and adjusting the output voltage to a first voltage or a second voltage according to whether the output terminal is coupled to the load device; a path control circuit coupled to the output terminal, and A control module coupled to the path control circuit; When the output control circuit detects that the load equipment is not coupled with the output end, the path control circuit cuts off a power supply path from the output end to the control module, and the output control circuit adjusts the output voltage to the first voltage so as to enable the control module to enter a disabled state; when the output control circuit detects that the load device is coupled to the output end, the path control circuit shorts the power supply path, and the output control circuit adjusts the output voltage to the second voltage so as to enable the control module to enter the enabling state.
2. The ethernet power supply of claim 1 wherein the output control circuit comprises: A voltage divider coupled to a first end of the output terminal and providing an impedance according to the voltage level of the first end, and The voltage stabilizing circuit is coupled with a second end of the output end and the voltage dividing circuit and adjusts the output voltage according to the impedance; The voltage dividing circuit is not coupled with the power supply device according to the load equipment, the first end is a first potential to provide a first impedance, and the voltage stabilizing circuit adjusts the output voltage to the first voltage according to the first impedance; the voltage dividing circuit is coupled to the power supply device according to the load device to provide a second impedance, and the voltage stabilizing circuit adjusts the output voltage to the second voltage according to the second impedance.
3. The ethernet power supply of claim 2 wherein the voltage divider circuit comprises: The first voltage dividing circuit comprises a plurality of resistors which are coupled in series, and a node which is coupled with the voltage stabilizing circuit is formed between two resistors which are coupled in series; A second voltage dividing circuit coupled in series with the resistors, and An impedance control circuit connected in parallel with the second voltage dividing circuit and selectively bypassing the second voltage dividing circuit to enable the voltage dividing circuit to provide the first impedance or the second impedance; The impedance control circuit provides the first impedance by not bypassing the second voltage dividing circuit according to the first potential of the load equipment which is not coupled with the power supply device, and provides the second impedance by bypassing the second voltage dividing circuit according to the load equipment which is coupled with the power supply device.
4. The ethernet power supply of claim 2 wherein the output control circuit further comprises: A feedback circuit coupled to the voltage stabilizing circuit; The voltage stabilizing circuit adjusts a feedback signal of the feedback circuit into a first feedback signal according to the first impedance, and the power supply device adjusts the output voltage to the first voltage according to the first feedback signal, and the voltage stabilizing circuit adjusts the feedback signal into a second feedback signal according to the second impedance, and the power supply device adjusts the output voltage to the second voltage according to the second feedback signal.
5. The ethernet power supply of claim 2 wherein the output control circuit further comprises: A clamping circuit coupled to the voltage stabilizing circuit and the second terminal; the clamping circuit provides a clamping voltage according to the coupling of the load device to the power supply device, so that the voltage from the second end to a grounding end is equal to the combination of a voltage stabilizing voltage of the voltage stabilizing circuit and the clamping voltage.
6. The ethernet power supply of claim 5 wherein the clamp circuit comprises: a clamping element coupled to the voltage stabilizing circuit and the second terminal for providing the clamping voltage, and A bypass circuit connected in parallel with the clamping element; The bypass circuit bypasses the clamping element according to the first potential of the first end which is not coupled with the power supply device by the load equipment so as not to provide the clamping voltage.
7. The ethernet power supply of claim 2 wherein the path control circuit is further coupled to the output control circuit, the voltage divider circuit providing the first impedance when the first terminal is at the first potential and the path control circuit provides a first path voltage to the output control circuit.
8. The Ethernet power supply of claim 7, wherein the voltage divider circuit provides the second impedance when the first terminal is at a second potential or the path control circuit provides a second path voltage to the output control circuit.
9. The step-down control circuit is applied to an Ethernet power supply, the Ethernet power supply comprises a power supply device for providing an output voltage from a first end and a second end, and the power supply device comprises a feedback control circuit, wherein the feedback control circuit comprises a clamping element, a feedback circuit and a voltage stabilizing circuit which are coupled in series with the second end of the power supply device, and a first voltage dividing circuit which is coupled with the second end and the voltage stabilizing circuit, and the step-down control circuit comprises: A second voltage dividing circuit coupled in series with the first voltage dividing circuit; An impedance control circuit connected in parallel with the second voltage divider and coupled to the first end for selectively bypassing the second voltage divider to provide a first impedance or a second impedance to the voltage stabilizing circuit, and A bypass circuit coupled to the first end and connected in parallel with the clamping element; When the first end is at a first potential and a power supply path from the second end to the power supply pin is broken to provide a first path voltage to the impedance control circuit, the impedance control circuit does not bypass the second voltage dividing circuit and provides the first impedance to the voltage stabilizing circuit, and the bypass circuit bypasses the clamping element, so that the feedback circuit informs the power supply device to adjust the output voltage to a first voltage according to the first impedance.
10. The buck control circuit of claim 9, wherein when the first terminal is at a second potential or the power supply path is shorted to provide a second path voltage to the impedance control circuit, the impedance control circuit bypasses the second voltage divider circuit to provide the second impedance to the voltage regulator circuit, and the bypass circuit does not bypass the clamping element to provide a clamping voltage, so that the feedback circuit informs the power supply device to increase the output voltage to a second voltage according to the first impedance and the clamping voltage.
11. A control method of Ethernet power supply, the Ethernet power supply receives an input voltage, and is used for coupling a load device; the Ethernet power supply comprises a power supply device and a control module, and the control method of the Ethernet power supply comprises the following steps: the power supply device converts the input voltage into an output voltage, and an output end provides the output voltage to the load equipment; When the Ethernet power supply detects that the load equipment is not coupled with the power supply device, a power supply path from the output end to the control module is disconnected so as to disable the control module; adjusting the output voltage to a first voltage according to the load device not coupled to the power supply device; when the Ethernet power supply detects that the load equipment is coupled with the power supply device, the power supply path is short-circuited so as to enable the control module; The output voltage is adjusted to a second voltage according to the coupling of the load device to the power supply device.
12. The control method of claim 11, wherein the output terminal comprises a first terminal and a second terminal, and the control method further comprises the steps of: Providing an impedance according to the potential of the first end; Providing a first impedance for a first potential according to the load device not coupled to the power supply device; Adjusting the output voltage to the first voltage according to the first impedance; Providing a second impedance according to the load device coupled to the power supply device, and The output voltage is adjusted to the second voltage according to the second impedance.
13. The control method of claim 12, wherein the first impedance and the second impedance are provided by a first voltage divider circuit and a second voltage divider circuit, and the control method further comprises the steps of: according to the load device not coupled to the power supply device and the first end being the first potential without bypassing the second voltage dividing circuit, to provide the first impedance formed by the first voltage dividing circuit and the second voltage dividing circuit, and The second voltage dividing circuit is bypassed according to the coupling of the load device to the power supply device so as to provide the second impedance formed by the first voltage dividing circuit.
14. The control method according to claim 13, further comprising the step of: Providing a first feedback signal according to the first impedance; the power supply device adjusts the output voltage to the first voltage according to the first feedback signal; Adjusting the feedback signal to a second feedback signal according to the second impedance, and The power supply device adjusts the output voltage to the second voltage according to the second feedback signal.
15. The control method according to claim 12, further comprising the step of: providing a clamping voltage according to the coupling of the load device to the power supply device so that the voltage from the second terminal to a ground terminal is equal to the combination of the clamping voltage and a regulated voltage, and According to the load device not coupled to the power supply device, the first terminal is at the first potential and does not provide the clamping voltage.
16. The control method according to claim 12, further comprising the step of: Providing the first impedance when the first end is at the first potential and the power supply path is disconnected according to a first path voltage, and When the first end is at a second potential or the power supply path is shorted according to a second path voltage, the second impedance is provided.

Description

Ethernet power supply, voltage reduction control circuit and control method thereof Technical Field The present invention relates to an ethernet power supply, a control circuit and a control method thereof, and more particularly to an ethernet power supply with power saving function, a buck control circuit and a control method thereof. Background Power over Ethernet (Power over Ethernet; poE) is a standardized or proprietary technology that can transmit power and data over twisted pair wires to devices in an Ethernet network. The technique is primarily applicable to the use of an ethernet Power supply (Power Source Equipment; PSE) coupled to a load Device (PD) over at least one RJ45 network line to simultaneously transmit Power and data to the load Device. Therefore, the technology can be used without additional power sockets, so that the Ethernet power supply does not need to be additionally provided with the power sockets, and the time and the cost for configuring the power wires can be saved. However, most of the products currently on the market use an ethernet Power Supply (PSE) to communicate with a load device (PD) in a full-time handshake to determine whether the PSE should supply power to the correct PD. Thus, even if the PD is not connected or the PD has been disconnected, the PSE continues to send out a handshake signal for detection, such that Power is continuously lost while the PSE is on standby, resulting in current PSE failing to meet current efficiency energy regulations (e.g., but not limited to, doE, EC coc..etc.) for Power consumption under No Load (No Load Power) specifications. Therefore, how to design an ethernet power supply to reduce the power consumption of the ethernet power supply as much as possible when the load device is not connected to the ethernet power supply is a big issue for research by the present inventors. Disclosure of Invention In order to solve the above-mentioned problems, the present disclosure provides an ethernet power supply to overcome the problems of the prior art. Therefore, the Ethernet power supply is used for coupling with load equipment, and comprises a power supply device, an output control circuit, a path control circuit and a control module. The power supply device is used for converting an input voltage into an output voltage and providing the output voltage to the load equipment through the output end. The output control circuit is coupled to the output terminal and adjusts the output voltage to the first voltage or the second voltage according to whether the output terminal is coupled to the load device. The path control circuit is coupled to the output end, and the control module is coupled to the path control circuit. When the output control circuit detects that the load equipment is not coupled with the output end, the path control circuit breaks a power supply path from the output end to the control module, and the output control circuit adjusts the output voltage to a first voltage so as to enable the control module to enter a disabled state. When the output control circuit detects that the load device is coupled with the output end, the path control circuit shorts the power supply path, and the output control circuit adjusts the output voltage to the second voltage so as to enable the control module to enter an enabling state. In order to solve the above-mentioned problems, the present disclosure provides a buck control circuit to overcome the problems of the prior art. Therefore, the buck control circuit of the present disclosure is applied to an ethernet power supply, and the ethernet power supply includes a power supply device that provides an output voltage from a first end and a second end. The power supply device comprises a feedback control circuit, wherein the feedback control circuit comprises a clamping element, a feedback circuit and a voltage stabilizing circuit which are coupled in series with the second end of the power supply device, and a first voltage dividing circuit which is coupled with the second end and the voltage stabilizing circuit. The step-down control circuit comprises a second voltage division circuit, an impedance control circuit and a bypass circuit, and the second voltage division circuit is coupled with the first voltage division circuit in series. The impedance control circuit is connected in parallel with the second voltage division circuit and coupled with the first end to selectively bypass the second voltage division circuit to provide the voltage stabilizing circuit with the first impedance or the second impedance. The bypass circuit is coupled to the first end and connected in parallel with the clamping element. The power pin of the controller of the Ethernet power supply is coupled with the impedance control circuit and the bypass circuit. When the first end is at the first potential and the power supply path from the second end to the power supply pin is broken to provide the first path voltage to th