Abstract: Provided are circuits and methods for a digital controller for an electronic ballast for a fluorescent lamp, comprising a feed-forward loop that provides information about a voltage firing angle, and a pulse width modulator that controls a duty ratio of at least one power switch of the electronic ballast according to the information. The digital controller may include a duty ratio controller implemented in the pulse width modulator. The digital controller may include one or more functions such as dimming, maintaining high power factor throughout the dimming range, low lamp power detection, lamp soft-start, and DC-link capacitor over-voltage detection for end of life protection or lamp failure protection. In one embodiment the ballast is a single stage, single switch ballast.

Abstract: A multi-module bidirectional power converter may comprise a low side common node, a high side common node and at least first and second bidirectional DC/DC converter modules. The modules may comprise first and second low voltage switches, first and second high voltage switches and a transformer. The transformer may comprise a low side winding having first and second legs and a high side winding having first and second legs. The first leg of the low side winding may be connected with the first and second low voltage switches of the module. The second leg of the low side winding may be connected with the low side common node of the multi-module bidirectional power converter. The first leg of the high side winding may be connected with the first and second high voltage switches of the module. The second leg of the high side winding may be connected to the high side common node of the multi-module bidirectional power converter.

Abstract: This invention provides an electronic ballast for a fluorescent lamp, including a rectifier for converting an alternating current input voltage into a direct current output voltage, and a circuit including a combined power factor correction (PFC) stage and an inverter, wherein the PFC stage and the inverter share a switch. Also provided is a controller for an electronic ballast, including a duty ratio controller that controls a duty ratio of a switch of the ballast, and means for adjusting the duty ratio according to a nonlinear function, so that an arc is sustained across the lamp. The controller and the ballast allow dimming of the fluorescent lamp while maintaining a high power factor.

Abstract: This invention provides an integrated power supply for a controller of an electronic ballast for a fluorescent lamp. The integrated power supply couples output power from the electronic ballast and uses the coupled power to provide power to the controller. In one embodiment, the electronic ballast may include a rectifier for converting an alternating current input voltage into a direct current output voltage, and a circuit including a combined power factor correction (PFC) stage and an inverter, wherein the PFC stage and the inverter share a switch. Also provided is a controller for an electronic ballast. The controller may include a voltage mode or current mode duty ratio controller that controls a duty ratio of a switch of the ballast. The controller and the ballast allow dimming of the fluorescent lamp while maintaining a high power factor.

Abstract: In one embodiment a method is provided for requesting and receiving network statistics in-band of a data replication exchange. The method includes receiving, at a switch, a request packet, initiated from a data replication system, for in-band delivery of network statistics, modifying the request packet to include a command that can be processed by a data storage device that is periodically accessed in connection with the data replication system, sending the request packet including the command to the data storage device, receiving from the peripheral device, in response to the request packet including the command, a response packet that includes data responsive to the command, deleting from a data field of the response packet the data responsive to the command and adding to the data field network statistics data available to the switch, and sending the response packet including the network statistics data to one of another switch or a host device from which the request packet was sent.

Abstract: A multi-module bidirectional power converter may comprise a low side common node, a high side common node and at least first and second bidirectional DC/DC converter modules. The modules may comprise first and second low voltage switches, first and second high voltage switches and a transformer. The transformer may comprise a low side winding having first and second legs and a high side winding having first and second legs. The first leg of the low side winding may be connected with the first and second low voltage switches of the module. The second leg of the low side winding may be connected with the low side common node of the multi-module bidirectional power converter. The first leg of the high side winding may be connected with the first and second high voltage switches of the module. The second leg of the high side winding may be connected to the high side common node of the multi-module bidirectional power converter.

Abstract: N_Ports and F_Ports are provided with logic allowing designation of multiple virtual interfaces on a single host bus adaptor or other Fibre Channel interface, one virtual interface for each VSAN operating on the node interface. Node ports with this additional functionality are referred to as trunking N_Ports or TN_Ports. These ports have a functional design allowing creation of the multiple virtual interfaces as appropriate for the application at hand. This port design also includes logic for communicating with a peer fabric port to initialize and modify the configuration of the virtual interfaces on the TN_Port. A corresponding functional design and communication logic is provided for fabric ports, referred to herein as trunking F_Ports or TF_Ports.

Abstract: A system and method for communicating over a single virtual channel. The method includes reserving a first group of credits of a credit pool for a first traffic class and a second group of credits of the credit pool for a second traffic class. In addition, a first and second respective groups of tags are reserved from a tag pool for the first and second traffic class. A packet may then be selected from a first buffer for transmission over the virtual channel. The packet may include a traffic indicator of the first traffic class operable to allow the packet to pass a packet of the second traffic class from a second buffer. The method further includes sending the packet over the virtual channel and adjusting the first group of credits and the first group of tags based on having sent a packet of the first traffic class.

Abstract: Described herein are methods, systems, and apparatus for a controller for a power circuit that interfaces distributed power generation with a power distribution grid, comprising: a first portion, including a maximum power point tracker, that receives signals corresponding to the distributed power generation voltage and current, and outputs to the power circuit a signal for controlling the voltage of the distributed power generation; a second portion, including a current reference generator, a current controller, and a dc voltage controller, that receives signals corresponding to a dc voltage of the power circuit, the power distribution grid voltage and current, and the inverter current, and outputs signals for controlling the power circuit output voltage; wherein the current reference generator includes nonlinear circuit elements and generates a current reference signal from the dc voltage of the power circuit and the grid voltage and current; such that substantially harmonic-free power is injected into the p

Abstract: N_Ports and F_Ports are provided with logic allowing designation of multiple virtual interfaces on a single host bus adaptor or other Fiber Channel interface, one virtual interface for each VSAN operating on the node interface. Node ports with this additional functionality are referred to as trunking N_Ports or TN_Ports. These ports have a functional design allowing creation of the multiple virtual interfaces as appropriate for the application at hand. This port design also includes logic for communicating with a peer fabric port to initialize and modify the configuration of the virtual interfaces on the TN_Port. A corresponding functional design and communication logic is provided for fabric ports, referred to herein as trunking F_Ports or TF_Ports.

Abstract: Provided is a maximum power point (MPP) tracker for a PV cell inverter, and a PV cell inverter. The MPP tracker decouples output power oscillations from the input power generation and extracts maximum available power from the PV cell. The PV cell inverter uses the MPP tracker and generates a sinusoidal output current from the MPP tracker output. The sinusoidal output current may be fed to a power distribution grid. The PV cell inverter may use a pulse width modulation technique to cancel harmonics in the sinusoidal output current. The circuits use a minimum number of components and avoid use of large electrolytic capacitors.

Abstract: This invention provides an electronic ballast for a fluorescent lamp, including a rectifier for converting an alternating current input voltage into a direct current output voltage, and a circuit including a combined power factor correction (PFC) stage and an inverter, wherein the PFC stage and the inverter share a switch. Also provided is a controller for an electronic ballast, including a duty ratio controller that controls a duty ratio of a switch of the ballast, and means for adjusting the duty ratio according to a nonlinear function, so that an arc is sustained across the lamp. The controller and the ballast allow dimming of the fluorescent lamp while maintaining a high power factor.

Abstract: A method and apparatus facilitates and enhances the operation of the spanning tree protocol in bridged computer networks. An intermediate network device in accordance with the present invention includes an enhanced spanning tree engine that is configured to perform certain novel functions. First, the enhanced spanning tree engine is configured to identify and block ports at which messages are looped-back to the transmitting port, thereby avoiding the creation of network loops. In second aspect, the enhanced spanning tree engine rapidly transitions certain ports to a forwarding state to prevent associated applications from timing out and shutting down. Rather than moving the ports through blocking, listening and learning states before reaching the forwarding state, selected ports may be transitioned directly to the forwarding state.

Abstract: A port shutdown protocol coordinates among various components involved in the process of administratively bringing down a link at both ends of a link connecting two switches. Execution of the protocol avoids or reduces frame drops and/or reordering. In this protocol, peer switches perform various actions when bringing down an ISL in a synchronized manner. In one implementation, this protocol uses the Exchange Peer Protocol (EPP) as the underlying transport to carry the port shutdown protocol frames.

Abstract: The invention relates to a dynamic conversion circuit for improving the transient response of a switching DC-DC converter, such as in a voltage regulator module (VRM). The dynamic conversion circuit may be applied to a single phase or multiphase interleaved VRM of either isolated or non-isolated design configurations, and enhances power transfer from the input to the output of the DC-DC converter and tightly regulates the output voltage during harsh load current transients.

Abstract: Methods and devices are provided for detecting whether peer ports interconnecting two network devices can perform a novel protocol called Exchange Peer Parameters (“EPP”). If the peer ports are so configured to perform EPP, EPP services are exchanged between the peer ports. In a first phase, information is exchanged about peer port configurations of interest. In a second phase, the results of the exchange of information are applied to hardware and/or software of the respective ports, as needed.

Abstract: According to the present invention, methods and apparatus are provided to allow efficient and effective aggregation of ports into port channels in a fiber channel network. A local fiber channel switch can automatically identify compatible ports and initiate exchange sequences with a remote fiber channel switch to aggregate ports into port channels. Ports can be aggregated synchronously to allow consistent generation of port channel map tables.

Abstract: A digital controller for a voltage regulator module (VRM) having single phase or multiphase power converters, and an optional dynamic conversion circuit, is disclosed. The digital controller improves the transient response of the VRM during harsh load current transients, and permits a substantial reduction in output capacitance of the VRM. When used with multiphase interleaved power converters, for a given load current requirement, the digital converter permits the number of interleaved phases of the VRM to be minimized. A VRM with the digital controller demonstrates low cost, high power density, high efficiency, and fast transient response.

Abstract: Methods and devices are provided for detecting whether peer ports interconnecting two network devices can perform a novel protocol called Exchange Peer Parameters (“EPP”). If the peer ports are so configured to perform EPP, EPP services are exchanged between the peer ports. In a first phase, information is exchanged about peer port configurations of interest. In a second phase, the results of the exchange of information are applied to hardware and/or software of the respective ports, as needed.

Abstract: A controller circuit in a power supply system is configured to simultaneously control both a voltage regulator circuit and a dynamic power supply circuit. The controller circuit monitors voltage produced by the voltage regulator circuit. The voltage regulator circuit conveys power from a voltage source to a dynamic load such as a microprocessor, whose power consumption can change rapidly change during operation. Depending on a state (e.g., current value, trend, etc.) of the monitored voltage applied to the load by the voltage regulator circuit, the controller circuit can initiate activation of the dynamic power supply circuit in parallel with the voltage regulator circuit to selectively supply additional power to the load. Supplying additional power to the dynamic load during heavy load conditions prevents the regulated voltage supplied to the load from falling below a threshold value.