Microsemi Corp-analog Mixed Signal Group, Ltd.

Powerdsine, Ltd.

Microsemi Corporation

Cisco Technology, Inc.

Powerdsine Ltd. - Microsemi Corporation

Powersdsine, Ltd.-microsemi Corporation

Dror Korcharz

David Pincu

Arkadiy Peker

Alon Zeev Ferentz

Ilan Atias

Amir Lehr

Yair Darshan

Nadav Barnea

Shimon Elkayam

Roni Blaut

Migel Jacubovski

Tamir Langer

Yaniv Giat

Yuval Berson

Simon Kahn

Eli Ohana

Shawn Anthony Fahrenbruch

Hwangsoo Choi

Shiju Wang

Daniel Feldman

Shimon Cohen

Kevin Mark Smith, Jr

Amir Peleg

Poldi Rimboim

Chien Nguyen

Paul Okada

Gustavo E Aizenberg

Iian Atias

Itay Cohen

Raanan Levi

Mohamad A Saleh

A power control subsystem for controlling the supply of power transmitted to at least one node over communication cabling, the power control subsystem comprising: a plurality of references; a plurality of comparators, each of the comparators being associated with a particular one of the plurality of references; and a current limiter in communication with the plurality of comparators and arranged to limit current of the power transmitted over communication cabling responsive to the plurality of comparators.

Power control subsystem with a plurality of current limit values

A converter constituted of: an inductor; a plurality of electronically controlled switches; and a control circuitry arranged to operate in a buck-boost mode responsive to the output voltage of the converter being within a predetermined range of the input voltage of the converter, the control circuitry arranged in the buck-boost mode: responsive to a current flowing through the inductor being lower than a predetermined low current threshold, to control the switches to couple the inductor between the input voltage and a common potential; responsive to the current flowing through the inductor being greater than a predetermined medium current threshold, to control the switches to couple the inductor between the input voltage and the output voltage; and responsive to the current flowing through the inductor being greater than a predetermined high current threshold, to control the switches to couple the inductor between the output voltage and the common potential.

Hysteretic current mode control converter with low, medium and high current thresholds

A lighting circuit constituted of: a single dimming input; a pulse width modulation acceptance circuit arranged to convert a pulse width modulated dimming signal received at the single dimming input into a local dimming signal, the local dimming signal exhibiting a predetermined format; an analog voltage level acceptance circuit arranged to convert an analog voltage dimming signal received at the single dimming input into the local dimming signal exhibiting the predetermined format; and a luminaire driving circuit responsive to the local dimming signal.

Dimming input suitable for multiple dimming signal types

An LED driver arrangement wherein a low voltage IC is arranged to sample the voltage at a terminal of each of the respective electronically controlled switches controlling a plurality of LED strings each receiving power from a single source, with the single source providing voltage in excess of the voltage rating of the IC. For each electronically controlled switch a controllable current source and an isolating unidirectional electronic valve is provided, the respective current source being enabled only when the respective associated electronically controlled switch is at least partially closed thereby ensuring that the respective isolating unidirectional electronic valve associated with the respective illuminating LED string conducts, and the voltage at the terminal of the respective electronically controlled switch is thus seen by the IC when the associated LED string is producing illumination, the voltage then being lower than the maximum voltage rating of the IC.

Sampling external voltage which may exceed integrated circuit maximum voltage rating

A backlight system for light emitting diodes (LEDs), the backlight system constituted of: a controllable power source; a plurality of LED based luminaires arranged to receive power in parallel from the controllable power source; a plurality of driving circuitries, each of the plurality of driving circuitries arranged to control the light output of at least two of the plurality of LED based luminaires and further arranged to output information regarding the voltage drop of at least one of the at least two LED based luminaires controlled thereby, wherein the controllable power source is arranged to output a voltage whose value is responsive to the output information.

Distributed architecture voltage controlled backlight driver

A method of color control for a backlight utilizing colored light emitting diodes (LEDs), the method constituted of: providing a plurality of colored LED strings constituted of at least three different colors; lighting each of the plurality of colored LED strings to provide a backlight; providing a period wherein none of the colored LED strings are lit; obtaining during the provided period when none of the colored LED strings are lit, an indication of an ambient light; obtaining during the provided period when the colored LED strings are lit, an indication of the optical output of the colored LED strings; and controlling the lighting of the provided plurality of colored LED strings responsive to the received indication of ambient light and the received indication of the output of the colored LED strings. Preferably, the method is performed in cooperation with an on-board color sensor.

Color management for field-sequential LCD display

A chipset for powering and controlling a plurality of light emitting diode (LED) strings. The chipset includes a controller having a pulse width modulating (PWM) functionality and a data transfer interface circuitry; and at least one dissipative active element array comprising a plurality of dissipative active elements. The dissipative active element array(s) are packaged to be thermally separate from the controller. The PWM functionality is arranged to individually pulse width modulate a current flow through each of the LED strings. Each of the plurality of dissipative active elements is associated with a particular one of the plurality of LED strings and is arranged to limit the current flow of the pulse width modulated current that flows through the particular LED string to a value, the value being responsive to a value output by the controller via the data transfer interface circuitry.

Powering and controlling light emitting diodes via thermally separated arrays of dissipative active elements

A system for powering and controlling an LED backlight, the system comprising: a control circuitry; a controllable power source responsive to the control circuitry; and a plurality of LED strings receiving power from the controllable power source, the control circuitry being operative to control the output voltage of the controllable power source responsive to a function of an electrical characteristic of at least one of the plurality of LED strings.

Voltage controlled backlight driver

A secondary side post regulator arrangement for a plurality of LED strings. For each secondary winding, a first electronically controlled switch is provided arranged to control the power output, and a LED string is connected thereto. A second electronically controlled switch is further connected in series with the LED string, arranged to receive a PWM signal, thereby pulsing current through the LED string. A current sensing element is further provided outputting a voltage representation of the current through the LED string, and a synchronized sampling circuit is provided arranged to sample the voltage representation during the on period of the second electronically controlled switch. The sampled and held voltage representation is compared with a reference signal and fed back to control the first electronically controlled switch. The voltage output associated with each secondary winding is controlled, responsive to the reference voltage.

Secondary side post regulation for LED backlighting

A method and apparatus for preventing harmful transients resulting from a probing routine for a valid powered device detection signature in a network, the method comprising: operating power sourcing equipment to provide via its output port a pre-detection output voltage; obtaining an indication of the pre-detection output voltage; comparing the indication of the pre-detection output voltage with a pre-determined value; and in the event that the indication of the pre-detection output voltage is less than the pre-determined value; initiating a probing routine for a valid powered device detection signature. The higher voltage of the probing routine is thus not present at the output port in the absence of pre-detection of a potentially valid powered device detection signature.

Pre-detection of powered devices

An optical sampling and control element for use with a luminaire exhibiting a cycle and a frame, the optical sampling and control element being constituted of a color sensor in optical communication with the luminaire; and a sampler connected to the outputs of the color sensor, the sampler comprising an integrator arranged to integrate the outputs of the color sensor over a predetermined period less than the frame.

Integrated synchronized optical sampling and control element

A power control subsystem for controlling the supply of power transmitted to at least one node over communication cabling, the power control subsystem comprising circuitry to control current of a power transmitted over communication cabling, the circuitry being operative to provide current limiting for the power at a first threshold, and delayed over current cut-off of the power at a second threshold, the second threshold being lower than the first threshold.

Power control subsystem for powering a node over communication cabling

A fault detection mechanism for a LED string comprising a plurality of serially connected LEDs, the fault detection mechanism comprising: a control circuitry; and a voltage measuring means, in communication with the control circuitry, arranged to measure the voltage drop across at least one LED of the LED string, the control circuitry being operable to: measure the voltage drop, via the voltage measuring means, at a plurality of times, compare at least two of the measured voltage drops, and in the event the comparison of the at least two voltage drops is indicative of one of a short circuit LED and an open circuit LED, output a fault indicator.

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Bat Yam, Israel

Dror Korcharz