WO-2026091135-A1 - POWER SOURCING EQUIPMENT, BUCK CONTROL CIRCUIT AND CONTROL METHOD THEREFOR

WO2026091135A1WO 2026091135 A1WO2026091135 A1WO 2026091135A1WO-2026091135-A1

Abstract

Power sourcing equipment, for coupling to a powered device. The power sourcing equipment comprises a power supply apparatus, an output control circuit, a path control circuit and a control module. When the output control circuit detects that a powered device is not coupled to an output end of the power sourcing equipment, the path control circuit disconnects a power supply path from the output end to the control module, and the output control circuit adjusts an output voltage to a first voltage, so that the control module enters a disabled state. When the output control circuit detects that the powered device is coupled to the output end, the path control circuit short-circuits the power supply path, and the output control circuit adjusts the output voltage to a second voltage, so that the control module enters an enabled state. The present disclosure further relates to a buck control circuit, and a control method for power sourcing equipment.

Inventors

TU, KUAN-HSIEN
LEE, CHENG-CHIEH
LIU, Cheng-en
LIN, HSUAN-CHEN

Assignees

台达电子工业股份有限公司

Dates

Publication Date: 20260507
Application Date: 20241104

Claims (16)

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 is coupled to the output terminal and adjusts the output voltage to a first voltage or a second voltage depending on whether the output terminal is coupled to the load device. A path control circuit is coupled to this output terminal; and A control module, coupled to the path control circuit; Specifically, when the output control circuit detects that the load device is not coupled to the output terminal, the path control circuit disconnects a power supply path from the output terminal to the control module, and the output control circuit adjusts the output voltage to the first voltage 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 terminal, the path control circuit short-circuits the power supply path, and the output control circuit adjusts the output voltage to the second voltage to enable the control module to enter the enabled state.
The Ethernet power supply of claim 1, wherein the output control circuit includes: A voltage divider circuit is coupled to a first terminal of the output and provides an impedance based on the potential of the first terminal; and A voltage regulator circuit is coupled to a second terminal of the output terminal and the voltage divider circuit, and the output voltage is adjusted according to the impedance. The voltage divider circuit provides a first impedance based on the fact that the load device is not coupled to the power supply device and the first terminal is at a first potential, and the voltage regulator circuit adjusts the output voltage to the first voltage based on the first impedance; the voltage divider circuit provides a second impedance based on the fact that the load device is coupled to the power supply device, and the voltage regulator circuit adjusts the output voltage to the second voltage based on the second impedance.
The Ethernet power supply of claim 2, wherein the voltage divider circuit comprises: A first voltage divider circuit includes a plurality of resistors coupled in series, and a node is formed between two of the series-coupled resistors to couple the voltage regulator circuit. A second voltage divider circuit is connected in series with the resistors; and An impedance control circuit is connected in parallel with the second voltage divider circuit, and the second voltage divider circuit is selectively bypassed so that the voltage divider circuit provides the first impedance or the second impedance; The impedance control circuit provides the first impedance by not bypassing the second voltage divider circuit when the load device is not coupled to the power supply device and the first terminal is at the first potential; the impedance control circuit provides the second impedance by bypassing the second voltage divider circuit when the load device is coupled to the power supply device.
The Ethernet power supply as claimed in claim 2, wherein the output control circuit further includes: A feedback circuit is coupled to the voltage regulator circuit; The voltage regulator circuit adjusts a feedback signal of the feedback circuit to a first feedback signal based on the first impedance, and the power supply device adjusts the output voltage to the first voltage based on the first feedback signal; the voltage regulator circuit... The feedback signal is adjusted 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.
The Ethernet power supply as claimed in claim 2, wherein the output control circuit further includes: A clamping circuit is coupled to the voltage regulator circuit and the second terminal; The clamping circuit provides a clamping voltage based on the load device being coupled to the power supply device, such that the voltage from the second terminal to a ground terminal is equal to the sum of a regulated voltage of the voltage regulator circuit and the clamping voltage.
The Ethernet power supply of claim 5, wherein the clamping circuit comprises: A clamping element, coupled to the voltage regulator circuit and the second terminal, is used to provide the clamping voltage; and A bypass circuit is connected in parallel with the clamping element; The bypass circuit bypasses the clamping element so as not to provide the clamping voltage because the load device is not coupled to the power supply device and the first terminal is at the first potential.
The Ethernet power supply of claim 2, wherein the path control circuit is further coupled to the output control circuit, and the voltage divider circuit provides 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.
The Ethernet power supply of claim 7, wherein the voltage divider circuit provides the second impedance when the first terminal is a second potential, or when the path control circuit provides a second path voltage to the output control circuit.
A buck control circuit is applied to an Ethernet power supply, the Ethernet power supply including a power supply device that provides an output voltage via a first terminal and a second terminal, and the power supply device including a feedback control circuit; the feedback control circuit includes a clamping element series-coupled to a second terminal of the power supply device, a feedback circuit and a voltage regulator circuit, and a first voltage divider circuit coupled to the second terminal and the voltage regulator circuit, the buck control circuit including: A second voltage divider circuit is connected in series with the first voltage divider circuit; An impedance control circuit, connected in parallel with the second voltage divider circuit and coupled to the first terminal, selectively bypasses the second voltage divider circuit to provide a first impedance or a second impedance to the voltage regulator circuit; and A bypass circuit is coupled to the first terminal and connected in parallel to the clamping element; In this device, a power pin of a controller of the Ethernet power supply is coupled to the impedance control circuit and the bypass circuit. When the first terminal is at a first potential and a power supply path from the second terminal to the power pin is broken to provide a first path voltage to the impedance control circuit, the impedance control circuit does not bypass the second voltage divider circuit but provides the first impedance to the voltage regulator circuit. The bypass circuit bypasses the clamping element so that the feedback circuit notifies the power supply device to reduce the output voltage to a first voltage based on the first impedance.
In the step-down control circuit of claim 9, when the first terminal is a second potential, or when the power supply path is short-circuited and provides a second path voltage to the impedance control circuit, the impedance control circuit bypasses the second voltage divider circuit and provides the second impedance to the voltage regulator circuit, and the bypass circuit does not bypass the clamping element and provides a clamping voltage, so that the feedback circuit notifies the power supply device to adjust the output voltage to a second voltage according to the first impedance and the clamping voltage.
A control method for an Ethernet power supply, the Ethernet power supply receiving an input voltage and used to couple to a load device; the Ethernet power supply includes a power supply device and a control module, and the control method for the Ethernet power supply includes the following steps: The power supply device converts the input voltage into an output voltage, and provides the output voltage to the load device through an output terminal; When the Ethernet power supply detects that the load device is not coupled to the power supply device, it disconnects a power supply path from the output terminal to the control module to disable the control module; Since the load device is not coupled to the power supply device, adjust the output voltage to a first voltage; When the Ethernet power supply detects that the load device is coupled to the power supply device, it short-circuits the power supply path to enable the control module; The output voltage is adjusted to a second voltage according to the load device coupled to the power supply device.
The control method of claim 11, wherein the output terminal includes a first terminal and a second terminal, and the control method further includes the following steps: An impedance is provided based on the potential of the first terminal; A first impedance is provided based on the fact that the load device is not coupled to the power supply device and the first terminal is at a first potential; The output voltage is adjusted to the first voltage based on the first impedance. A second impedance is provided based on the coupling of the load device to the power supply device; and The output voltage is adjusted to the second voltage based on the second impedance.
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 includes the following steps: Based on the fact that the load device is not coupled to the power supply device, and the first terminal is at the first potential without bypassing the second voltage divider circuit, the first impedance formed by the first voltage divider circuit and the second voltage divider circuit is provided; and The second voltage divider circuit is bypassed based on the load device being coupled to the power supply device, so as to provide the second impedance formed by the first voltage divider circuit.
The control method of claim 13 further includes the following steps: A first feedback signal is provided based on the first impedance; The power supply device adjusts the output voltage to the first voltage according to the first feedback signal; The feedback signal is adjusted to a second feedback signal based on the second impedance; and The power supply device adjusts the output voltage to the second voltage according to the second feedback signal.
The control method of claim 12 further includes the following steps: A clamping voltage is provided based on the load device coupled to the power supply device, such that the voltage from the second terminal to a ground terminal is equal to the sum of the clamping voltage and a regulated voltage; and The load device is not coupled to the power supply device, and the first terminal is at the first potential and does not provide the clamping voltage.
The control method of claim 12 further includes the following steps: When the first terminal is at the first potential and the power supply path is disconnected according to a first path voltage, the first impedance is provided; and The second impedance is provided when the first terminal is at a second potential, or when the power supply path is short-circuited according to a second path voltage.

Description

An Ethernet power supply, a step-down control circuit, and a control method thereof. Technical Field This invention relates to an Ethernet power supply, a control circuit, and a control method thereof, and particularly to an Ethernet power supply with power-saving function, a step-down control circuit, and a control method thereof. Background Technology Power over Ethernet (PoE) is a standardized or proprietary technology that transmits power and data to devices over an Ethernet network via twisted-pair cabling. This technology primarily uses a Power Source Equipment (PSE) to couple to a power device (PD) via at least one RJ45 network cable to simultaneously transmit power and data. Therefore, this technology eliminates the need for an additional power outlet, saving time and money on power cable configuration. However, most current products on the market rely on a continuous handshake signal communication between the Ethernet Power Supply (PSE) and the load device (PD) to determine whether the PSE should supply power to the correct PD. Therefore, even when the PD is not connected or has been disconnected, the PSE continues to send handshake signals for detection, resulting in continuous power loss during PSE standby. This means that current PSEs cannot meet the power consumption requirements under current energy efficiency regulations (such as, but not limited to, DoE, EC CoC, etc.) regarding no-load power consumption. Therefore, how to design an Ethernet power supply that minimizes the power consumption of the Ethernet power supply when the load device is not connected to the Ethernet power supply is a major research topic that the inventors of this disclosure intend to study. Summary of the Invention To address the aforementioned problems, this disclosure provides an Ethernet power supply to overcome the limitations of existing technologies. Therefore, the Ethernet power supply of this disclosure is used to couple a load device, and includes a power supply device, an output control circuit, a path control circuit, and a control module. The power supply device converts an input voltage into an output voltage and provides the output voltage to the load device from its output terminal. The output control circuit is coupled to the output terminal and adjusts the output voltage to a first voltage or a second voltage depending on whether the output terminal is coupled to a load device. The path control circuit is coupled to the output terminal, and the control module is coupled to the path control circuit. Specifically, when the output control circuit detects that the load device is not coupled to the output terminal, the path control circuit disconnects the power supply path from the output terminal to the control module, and the output control circuit adjusts the output voltage to the first voltage to disable the control module. When the output control circuit detects that the load device is coupled to the output terminal, the path control circuit short-circuits the power supply path, and the output control circuit adjusts the output voltage to the second voltage to enable the control module. Use states. To address the aforementioned problems, this disclosure provides a buck control circuit to overcome the limitations of the prior art. Therefore, the buck control circuit of this disclosure is applied to an Ethernet power supply, which includes a power supply device providing an output voltage via a first terminal and a second terminal. The power supply device includes a feedback control circuit, which includes a clamping element, a feedback circuit, and a voltage regulator circuit connected in series to the second terminal of the power supply device, and a first voltage divider circuit coupled to the second terminal and the voltage regulator circuit. The buck control circuit includes a second voltage divider circuit, an impedance control circuit, and a bypass circuit, with the second voltage divider circuit connected in series to the first voltage divider circuit. The impedance control circuit is connected in parallel to the second voltage divider circuit and coupled to the first terminal to selectively bypass the second voltage divider circuit and provide a first impedance or a second impedance to the voltage regulator circuit. The bypass circuit is coupled to the first terminal and connected in parallel to the clamping element. The power supply pin of the controller of the Ethernet power supply is coupled to the impedance control circuit and the bypass circuit. When the first terminal is at the first potential, and the power supply path from the second terminal to the power supply pin is broken to provide the first path voltage to the impedance control circuit, the impedance control circuit does not bypass the second voltage divider circuit but provides the first impedance to the voltage regulator circuit, and the bypass circuit bypasses the clamping element so that the feedback circuit notifies the power