Linear Technology Corporation

Topside Research, LLC

Analog Devices International Unlimited Company

Internet Machines Corp.

Analog Devices,inc.

Avago Technologies General IP (singapore) Pte. Ltd.

Heath Stewart

Chris Haywood

Jeffrey Lynn Heath

Michael J De La Garrigue

Andrew J Gardner

David McLean Dwelley

Michael Paul

Thomas C Reiner

Ken Wong

Gitesh Bhagwat

Bao K Vuong

Nadim Shaikli

Harry Joseph Kleeburg

Adam Rappoport

David Stover

Michael T Paul

Mike De La Garrigue

David M Stover

Jeffery Lynn Heath

A network node device for coupling to a network via a shared link that carries power and data. The network node device includes: one or more data transceivers to transmit and receive data over the shared link; physical layer circuitry (PHY) to transmit and receive data with the one or more data transceivers; and a galvanic isolation barrier coupled between the PHY and the one or more data transceivers, wherein the PHY transmits and receives the data with the one or more data transceivers over the galvanic isolation barrier.

Isolated transceiver for power over ethernet

A Power over Data Lines (PoDL) system provides a DC voltage and differential data signals on the same wire pair. A Powered Device (PD) load is coupled to the wire pair, via a gyrator, for being powered by the DC voltage. The gyrator emulates the DC-coupling properties of inductors using active components. The gyrator includes transistors that are controlled to act as a full-bridge rectifier for ensuring a correct polarity DC voltage is applied to the PD load. Since the transistors operate in saturation and are coupled to be insensitive to differential data signals on the wire pair, the current supplied to the PD load is substantially unaffected by the differential data signals. Negative feedback circuits in the gyrator reduce fluctuations in current through the gyrator due to differential data signals on the wire pair. No inductors are required in the gyrator. A PHY is AC-coupled to the wire pair via capacitors.

PoDL powered device with active rectifier bridge to obviate the need for DC-coupling inductors

A PoDL system uses a gyrator for DC coupling of DC power from a PSE to a wire pair, and/or decoupling DC power from a wire pair for a PD. The gyrators obviate the use of discrete inductors for DC-coupling/decoupling and can be formed as an integrated circuit. The gyrators use a small integrated capacitor and invert and multiply the capacitor effect to emulate an inductor. The gyrators present a high impedance to AC current and a low impedance to DC current. Various gyrator designs, such as positive and negative polarity gyrators, and configurations are disclosed. Gyrators are described with analog current limit and power switch control, so multiple functions are integrated on the same IC chip.

Active gyrator circuit in one-pair ethernet with PoDL

A PoE system includes a PSE connected via a shielded twisted wire pair to a PD, where differential data is transmitted over only the wire pair, and where DC power is transmitted via the wires in the wire pair conducting a DC voltage in parallel while using the shield conductor as ground. A low power handshaking routine is performed by a PSE controller and a PD controller by conducting a source current through the wires in parallel and a return current through the shield conductor. Center tap auto-transformers are used to connect the two wires to the PSE and PD controllers and to a DC voltage source in the PSE. After a successful handshaking routine, the PSE couples the DC voltage source between the wire pair and the shield conductor by closing a first power switch. The PD controller then closes a second power switch to power a load.

Power over ethernet using shielded single twisted wire pair

One or more Power Sourcing Equipment (PSE) are coupled to points in a network of interconnected nodes. Each node has a first port and a second port. Assume the first port of a first node is receiving DC power from the PSE. The first node, at its second port, then detects an electrical signature from a first port of an adjacent second node. If the proper electrical signature is presented by the adjacent second node, the powered first node closes a switch to pass power between its first port and second port to power the second node via the first port of the second node. All nodes in the network are then sequentially powered up in this manner. If there is a fault between the first node and the second node, the second node will be powered by another node connected to the second port of the second node.

Fault-tolerant power network

The invention pertains to systems where DC power is supplied by a PSE to a PD, such as over differential data wire pairs. IEEE standards require a minimum current to be drawn from the PD in order for the PSE to continue supplying the DC voltage. If the PD is in a low power mode, the PSE will normally discontinue supplying the DC voltage, which then requires a new detection and classification routine for powering up again. To avoid this, a 'maintain power signature' controller provides a periodic current pulse by a current source connected between the PD input and the PD's full bridge rectifier. Any droop in the DC voltage that reverse biases the full bridge rectifier while the PD is in its low power mode will not affect the current pulse, so the PSE continues to supply the DC voltage.

Maintain power signature controller at power interface of PoE or PoDL system

There is disclosed apparatus and methods of multicasting in a shared address space. A shared memory address space may include two or more multicast portions. Each multicast portion may be associated with a respective end point and with at least one other multicast portion. Data units may be transmitted to at least some of the end points via memory-mapped I/O into the shared memory address space. When a destination address of a data unit is in a first multicast portion associated with a first end point, the data unit may be transmitted to the first end point, revised to specify a destination address in a second multicast portion associated with the first multicast portion, and transmitted to a second end point associated with the second multicast portion.

Multicasting computer bus switch

A system includes a master and a slave coupled via a wire pair for transmitting differential data. The master and slave are each powered by a local DC power supply. In a normal mode, a DC voltage and differential data are supplied over the same wire pair. The differential data is processed by a PHY AC-coupled to the wire pair. To enter a low power sleep mode, such as due to a temporary non-use of the system, the master interrupts the DC voltage on the wire pair, which signals to the slave to enter the sleep mode. The system is woken up by reapplying the DC voltage to the wire pair to signal to the slave to wake up. Only the DC path, and not the data path, is used for signaling the sleep mode and awake mode, so the data path can be disabled to conserve power.

System with sleep and wake up control over DC path

An anemometer and method for analyzing fluid flow is described. In one embodiment, a transistor sensor is heated by applying power to cause its base-emitter junction to rise from an ambient first temperature to a second temperature. The power is removed, and the Vbe is measured at intervals as the junction cools. The Vbe equates to a temperature of the junction. The temperature exponentially decreases, and the time constant of the decay corresponds to the fluid flow velocity. A best fit curve analysis is performed on the temperature decay curve, and the time constant of the exponential decay is derived by a data processor. A transfer function correlates the time constant to the fluid flow velocity. The transistor is thermally coupled to a metal rod heat sink extending from the package, and the characteristics of the rod are controlled to adjust the performance of the anemometer.

Method of manufacturing an anemometer used for determining a fluid flow

A PSE includes a PSE controller that performs a handshaking routine with any PDs connected to the data wire pairs and spare wire pairs and applies power to the data wire pairs and spare wire pairs, via a switch, if certain conditions are met. Two different levels of currents are supplied to different terminals of the PSE controller that are connected to the data wire pairs and the spare wire pairs, and the resulting voltages are measured. The voltages are used to determine the PD impedances at the ends of the data wire pairs and spare wire pairs to determine whether a PD is connected to the data wire pair, whether another PD is connected to the spare wire pair, or whether a single PD is connected to both the data wire pairs and the spare wire pairs.

PSE controller in PoE system detects different PDs on data pairs and spare pairs

In a method performed by a PoE system, a PSE is able to detect whether a PD is compatible for receiving power via four wire pairs in the standard Ethernet cable. The PSE provides a current limited voltage to a first and second pair of wires in the cable, during a detection phase, to detect a characteristic impedance of the PD. In the PSE, a first resistor is connected to a third wire pair and a second resistor is connected to a fourth wire pair. During the detection phase, the PSE detects the relative currents through the resistors. If the currents are the same, then the PSE knows the PD is able to receive power via the four wire pairs. The PSE then applies the full PoE voltage to the first and second wire pairs and connects the third and fourth wire pairs to a low voltage via a MOSFET.

Detection scheme for four wire pair Power Over Ethernet system

Power Sourcing Equipment (PSE) provides a PoE supply voltage over data wires to a Powered Device (PD). A PSE controller controls a first FET that couples the PoE voltage to the data wire pairs and controls a second FET that couples the data wire pairs to the spare wire pairs. Upon powering up, the PSE controller keeps the two FETs open and performs a detection routine on any devices connected to the data pairs and spare pairs. If a PoE-compatible PD is detected as being coupled to the data pairs, the first switch is closed. If it is determined that the PoE voltage should also be coupled to the spare pairs, the second FET is also closed. The method prevents the PoE voltage from being applied to the spare pairs when the device connected to the spare pairs is not PoE compatible and maintains backwards compliance with IEEE PoE PDs.

Power over Ethernet on data pairs and spare pairs

Anemometer detecting thermal time constant of sensor

Methods for routing data units and PCI Express switches are disclosed. A plurality of devices may be coupled to a corresponding plurality of physical interfaces, each physical interface having a respective configurable status and a respective address domain, wherein in a first status the interface is transparent, and in a second status the interface is non-transparent. The status of each of the plurality of physical interfaces may be set as transparent or non-transparent. Data units may be switched between the physical interfaces using mapped address input/output, switching data units including masking the address domain for the interfaces configured as non-transparent.

Routing data units between different address domains

There are disclosed apparatus and methods for switching. Transparent and non-transparent ports are provided. Data units are transferred between the transparent ports, between the transparent and non-transparent ports, and between the non-transparent ports.

Growing community of inventors

Santa Barbara, CA, United States of America

Heath Stewart