Broadcom Corporation

Cisco Technology, Inc.

Nortel Networks Corporation

Avago Technologies General IP (singapore) Pte. Ltd.

Neven Pischl

Ahmad Chini

Yongbum Kim

Mehmet Vakif Tazebay

Sesha Thalpasai Panguluri

John B Lockwood

Mohammad Tabatabai

Joseph Laurence Cordaro

A circuit for power on data line (PoDL) injection includes a power source, a first and a second coupling component, and an interface. The power source provides one or more DC voltage levels. The first coupling component couples the power source to an interface for coupling to a transmission medium. An Ethernet device is coupled through the second coupling component to the interface. The first coupling component is a balanced component, and the Ethernet device is isolated from the power source via a pair of DC blocking capacitors connected between the first coupling component and the second coupling component.

Power coupling circuits for single-pair ethernet with automotive applications

A method and system for mitigating transformer saturation in a communication interface is provided. The method may include detecting a change in impedance resulting from transformer saturation of at least one isolation transformer utilized in a network path of a network. The network may conform to an IEEE 802.3af specification where power may be delivered through the network. The method may further comprise generating a pulse at a one end of the network and measuring a reflection at that end to detect the transformer saturation. In response to the impedance change, a transmitter signal may be pre-distorted in order to compensate for the detected transformer saturation, or the power delivered over the network may be disabled.

Method and system for mitigating transformer saturation in a communication interface

Common-mode termination within communication systems. Termination is implemented with respect to two respective portions of a system: the intentional signaling within a communication system as well as any unintentional signaling which may be coupled into the system. Such unintentional signaling may be incurred in a variety of ways including via interference which may be generated by the system itself or by other devices or components external to the system. In addition, such unintentional signaling made be characterized as common-mode (CM) signaling, in that, it generally affects different respective portions of the system similarly or in the same manner. Various communication systems may include two or more devices implemented therein, that effectuate signaling via one or more communication links there between. Appropriate termination is made with respect to both the intentional and unintentional signaling portion of the system using any of a variety of impedance types (e.g., resistors, capacitors, inductors, etc.).

Common-mode termination within communication systems

Disclosed is a communications interface to connect to a first device and to establish a communication between the first device and a second device over a medium. The communications interface comprises at least one common mode choke having a first end configured to connect to an Ethernet transceiver of the first device. The communications interface further comprises an optional capacitor having a first end coupled to a second end of the at least one common mode choke and having a second end configured to connect to the medium. The communications interface does not include any transformers connected to the second end of the at least one common mode choke. The Ethernet communications is readily adaptable to differential-pair cabling and applications in harsh electromagnetic interference environments, such as automotive, aero-space, air crafts, water crafts, trains, railroad and marine applications, where high rejection of EMI is required.

Communications interface to differential-pair cabling

Embodiments allow for the use of the SS modulation technique (and thus for significant reduction of EMI due to clock transmission) in scenarios involving tight synchronization requirements between two devices. In particular, embodiments can be used in high-speed communication networks (e.g., high-speed Ethernet) where a clock signal embedded in the data stream at the transmitter and recovered from the data stream at the receiver is the only source for synchronization between the transmitter and the receiver (i.e., no other synchronization channel available). Embodiments are also especially useful in communication systems utilizing echo cancellers.

Recovery and synchronization for spread spectrum modulated clock

According to one exemplary embodiment, a connector for coupling a communications medium to an electronic device includes a common-mode suppression block coupled to a number of connector pins. The common-mode suppression block is configured to reduce common-mode noise coupling between the communications medium and the connector pins in the connector. The common-mode suppression block is further configured to provide substantially no attenuation to a differential-mode signal. In one embodiment, the communications medium is an Ethernet cable and the connector is an Ethernet plug. In one embodiment, the common-mode suppression block comprises common-mode chokes. In one embodiment, the connector is an RJ45 plug.

Communications medium connector with integrated common-mode noise suppression

A conductive area or layer of a circuit board is aligned with, and spaced from, a portion of a first differential signal conductor pair and connected through a conductive pathway to one of the conductors of a second differential signal conductor pair to provide capacitive coupling for compensating an imbalance arising from non-symmetric pin assignments. By compensating the imbalance, signal quality and/or immunity is improved and noise and/or emission is reduced.

Connector imbalance compensation apparatus and method

According to one embodiment of the present invention, a voltage probe for measuring common-mode (CM) voltage of a device under test (DUT) having differential input/output (I/O) signals is disclosed. The probe includes a connector adapted to couple to the DUT, at least one output measurement port configured to connect to a measuring device for measuring the CM voltage, and at least one differential pair cable connected to a connector and to a at least one measurement port for coupling a differential I/O signals to a measurement port. According to a second embodiment, the present invention provides a voltage probe for measuring CM voltage of a DUT having differential I/O signals while the DUT is simultaneously connected to an auxiliary equipment. According to a third embodiment, the present invention provides a method for measuring EMI from a DUT. A CM voltage probe is interposed between the DUT and an EMI measurement device. The CM voltage is measured at an measurement port of the voltage probe. The measured CM voltage is compared to a limit for EMI.

Growing community of inventors

Santa Clara, CA, United States of America

Neven Pischl