| MICROSEMI CORPORATION Patent applications |
| Patent application number | Title | Published |
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| 20120098505 | PHASE-CUT DIMMING CIRCUIT - Methods, systems, and devices are described for sensing a phase-cut dimming signal and outputting a control signal compatible with a switching power circuit. Embodiments of the invention generate at least one of a low-frequency pulse-wave-modulated control signal, an analog output control signal, or a digital (e.g., higher-frequency pulse-wave-modulated) output control signal. Some embodiments further provide preloading and/or startup control functionality to allow proper functioning of the circuitry under small-conduction-angle (i.e., highly dimmed) conditions. | 04-26-2012 |
| 20120098442 | SYNCHRONOUS REGULATION FOR LED STRING DRIVER - A light emitting diode (LED) based luminaire driving arrangement constituted of: a switched driver; a plurality of LED based luminaires arranged to receive power from the switched driver; at least one electronically controlled switch in series with at least one of the plurality of LED based luminaires and arranged to alternatively pass current through the at least one LED based luminaire when closed and prevent the flow of current through the at least one LED based luminaire when opened; and at least one synchronous driver in communication with the at least one electronically controlled switch, the at least one synchronous driver arranged to close the at least one electronically controlled switch only when the switched driver is actively supplying power. | 04-26-2012 |
| 20120044729 | BRIDGELESS COUPLED INDUCTOR BOOST POWER FACTOR RECTIFIERS - A bridgeless power factor correction system may include an AC input having a first input terminal and a second input terminal, an inductor module coupled with the first input terminal, and a switching module coupled between the second input terminal and the inductor module. The switching module may comprise a bi-directional voltage blocking switch that is configured to selectively couple the inductor module with the AC input based on an output voltage and a phase difference between an input voltage waveform and an input current waveform. The switching module may also comprise an auxiliary network for reversing a winding current to achieve zero voltage switching. An output module may be coupled with the inductor module, and provide an output to a load. The inductor module may include a magnetically coupled inductor having a primary and secondary winding. The output module may include a full or half bridge rectifier. | 02-23-2012 |
| 20120032728 | AUTO-OPTIMIZATION CIRCUITS AND METHODS FOR CYCLICAL ELECTRONIC SYSTEMS - Methods, systems, and devices are described for an adjustment module that interacts with a parameter detection module to provide a threshold value for initiating switching of a switching module in a cyclical electronic system. Aspects of the present disclosure provide a switching module used in conjunction with an inductor that is coupled with the switching module. The threshold voltage for switching the switching module may be adjusted to provide switching at substantially zero volts while maintaining sufficient energy in the inductor to drive the voltage at a switching element in the switching module to zero volts. Such auto-adjustment circuits may allow for enhanced efficiency in cyclical electronic systems. The output of an up/down counter may be used to set another parameter that effects the performance of the cyclical electronic system in order to enhance the performance of the cyclical electronic system. | 02-09-2012 |
| 20120032708 | GATE DRIVER POWER AND CONTROL SIGNAL TRANSMISSION CIRCUITS AND METHODS - Methods, systems, and devices are described for both power and control signal transmission through a single coupled inductor. A current driver generates a cyclical current signal on a primary winding of a coupled inductor, to induce a voltage signal at the secondary winding corresponding to the cyclical current signal. A rectifier module is coupled with the secondary winding and configured to rectify the signal induced at the secondary winding. A control timing signal module is coupled with the primary winding and configured to induce voltage pulses on the secondary winding, the induced voltage pulses having an insubstantial impact on the output of the rectifier module. A switching module coupled with the secondary winding is configured to receive the voltage pulses and control a switching signal for a power switch coupled with the output of the rectifier and provide power to a load coupled with the output of the rectifier. | 02-09-2012 |
| 20120032664 | SINGLE INDUCTOR POWER CONVERTER SYSTEM AND METHODS - Methods, systems, and devices are described for a non-isolated dc-dc power converter that uses a single magnetic element and provides both a positive and a negative voltage output. The magnetic element, such as an inductor, is coupled with two or more switching modules that electrically switch the inductor to and from a voltage source, an inductor terminal, and/or a load. By electrically connecting and electrically isolating different components at various times, separate positive and negative voltage outputs are provided using the single inductor element. Switching may be controlled by a controller module, and a magnitude of the dc output voltage may be selected based on two or more resistors coupled with the controller module. | 02-09-2012 |
| 20120025735 | FLYBACK WITH SWITCHING FREQUENCY RESPONSIVE TO LOAD AND INPUT VOLTAGE - A power source constituted of: a power factor corrector controller; an electronically controlled switch responsive to the power factor corrector controller; a first inductor serially connected with the electronically controlled switch and arranged to pass a direct current there through when the electronically controlled switch is closed; a second inductor magnetically coupled to the first inductor and coupled to provide power to a load in a flyback arrangement; a third inductor magnetically coupled to the first inductor, a first end of the third inductor arranged to provide a representation of the voltage level of the direct current when the electronically controlled switch is closed, and to provide a representation of the voltage level of the power provided to the load when the electronically controlled switch is open; and an off time control circuit in communication with the power factor corrector controller and responsive to the third inductor representations. | 02-02-2012 |
| 20120019156 | LED STRING DRIVER WITH NON-DISSIPATIVE REACTANCE BALANCER - A solid state lighting arrangement constituted of: a power source providing a current which is discontinuous in at least one direction; a plurality of light emitting diode (LED) strings arranged to receive the provided current from the power source; and a plurality of reactance elements, each of the plurality of reactance elements arranged in series with a particular one of the plurality of LED strings, such that current flowing from the power source through each of the LED strings creates a voltage drop across the series arranged reactance element, wherein the voltage drop across each of the series arranged reactance elements responsive to the discontinuous current is at least 10 times greater than the maximum difference between the voltage drops among the plurality of LED strings. | 01-26-2012 |
| 20120013259 | LED STRING DRIVER ARRANGEMENT WITH NON-DISSIPATIVE CURRENT BALANCER - A solid state lighting driver arrangement exhibiting a plurality of LED strings receiving power from a single power source, the single power source providing a discontinuous current, wherein a plurality of first windings are provided, each associated with a particular LED string and coupled to provide current balancing between the various LED strings. The discontinuous current resets the windings during the off time or during a reversal period. In one particular embodiment, a second winding is magnetically coupled to each of the first windings, and the second windings are connected in a closed in-phase loop. In another particular embodiment, at least two of the first windings are magnetically coupled to each other, thus ensuring a balance between current in each LED string. | 01-19-2012 |
| 20120009886 | ARCHITECTURE FOR COEXISTENCE OF MULTIPLE BAND RADIOS - A front end module for use with a first and a second radio frequency transceiver, constituted of: a control circuitry; a first antenna connection port; a second antenna connection port; a filter arranged to substantially attenuate the carrier frequency bandwidth of the second radio frequency transceiver; and a plurality of electronically controlled switches, wherein the control circuitry is arranged to: in the event that the first and second radio frequency transceivers are simultaneously operative, set the plurality of electronically controlled switches to connect the first radio frequency transceiver to one of the first and second antenna connection ports via the filter; and in the event that the first and second radio frequency transceivers are not simultaneously operative, set the plurality of electronically controlled switches to bypass the filter and connect the first radio frequency transceiver to one of the first and second antenna connection ports. | 01-12-2012 |
| 20110304280 | LIPS BACKLIGHT CONTROL ARCHITECTURE WITH LOW COST DEAD TIME TRANSFER - A driving circuitry arranged to pass a dead time over an isolation transformer, the driving circuitry constituted of: a three-state driver arranged to output a first signal, the first signal selectively at one of two complementary voltage levels and a high impedance state; a first capacitor, a first end of the first capacitor coupled to receive the first signal; and a first isolation transformer, a first end of a first winding of the first isolation transformer coupled to a second end of the first capacitor. | 12-15-2011 |
| 20110248639 | SAMPLING EXTERNAL VOLTAGE WHICH MAY EXCEED INTEGRATED CIRCUIT MAXIMUM VOLTAGE RATING - 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. | 10-13-2011 |
| 20110242767 | MECHANICAL ISOLATION AND THERMAL CONDUCTIVITY FOR AN ELECTRO-MAGNETIC DEVICE - An electro-magnetic device assembly constituted of an electro-magnetic device; a chassis arranged to sink heat; at least one thermally conductive material in thermal communication with the electro-magnetic device and with the chassis; and at least one mechanically isolating material in contact with the thermally conductive material and with the chassis, the at least one mechanically isolating material arranged to dampen the transmission of vibrations experienced by the chassis, in the direction of the magnetic field of the electro-magnetic device, to the electro-magnetic device. | 10-06-2011 |
| 20110187283 | DIMMING INPUT SUITABLE FOR MULTIPLE DIMMING SIGNAL TYPES - 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. | 08-04-2011 |
| 20110181204 | BALANCING TRANSFORMERS FOR MULTI-LAMP OPERATION - A ring balancer comprising a plurality of balancing transformers facilitates current sharing in a multi-lamp backlight system. The balancing transformers have respective primary windings separately coupled in series with designated lamps and have respective secondary windings coupled together in a closed loop. The secondary windings conduct a common current and the respective primary windings conduct proportional currents to balance currents among the lamps. The ring balancer facilitates automatic lamp striking and the lamps can be advantageously driven by a common voltage source. | 07-28-2011 |
| 20110148381 | CONVERTER WITH CROSSOVER FREQUENCY RESPONSIVE TO SWITCHING FREQUENCY - A power converter constituted of: a reference source; a clock generator exhibiting a variable frequency output, the value of the frequency of the variable frequency output responsive to an input signal; and an error amplifier in communication with the reference source, the error amplifier exhibiting a gain whose value is responsive to the input signal. Preferably the error amplifier is a transconductance amplifier. In one embodiment the power converter further exhibits a current squarer, arranged to produce a squared value of the input signal and provide the squared value to the transconductance amplifier. | 06-23-2011 |
| 20110141775 | NON-DISSIPATIVE START UP CIRCUIT - A start up circuit constituted of: a first alternating current lead; a second alternating current lead, said second alternating current lead exhibiting an opposing phase of said first alternating current lead; a first capacitor, a first end of said first capacitor coupled to said first alternating current lead; a second capacitor, a first end of said second capacitor coupled to said second alternating current lead; a breakdown diode coupled between a second end of said first capacitor and a second end of said second capacitor; and a third capacitor coupled in parallel with said breakdown diode. A direct current power is developed across the breakdown diode without requiring dissipative elements. | 06-16-2011 |
| 20110117705 | MULTI-LAYER THICK-FILM RF PACKAGE - A method for producing a multi-layer thick-film RF package includes forming conductive layer(s) including one or more source portions, one or more gate portions, and/or one or more drain portions on a ceramic substrate. The conductive layer(s) and the ceramic substrate are fired or otherwise heated in a furnace until sintered. Thereafter, a dielectric pattern is formed on the conductive layer(s) and fired or otherwise heated in the furnace until sintered. Then, a conductive bridge is formed on the dielectric pattern, over the one or more drain portions and between the one or more source portions, which is then fired until sintered in the furnace. As a result, a monolithic, single-piece, sintered, high-frequency RF power transistor package having circuit features including a highly conductive and low capacitive bridge is produced. | 05-19-2011 |
| 20110116237 | RF PACKAGE - An RF package includes a substrate mountable on a base plate, a non-conductive cover overlying the substrate, and quasi-serpentine stepped source leads attached to an upper surface of the substrate and extending from at least one of a pair of opposite sides of the upper surface of the substrate to tapered lower surfaces of the cover. The cover includes a recess to receive the substrate. The recess includes stress distribution surface areas to engage and press outer edge portions of opposite sides of the substrate against a base plate or heat sink. The tapered lower surfaces of the cover engage with and press against the stepped source leads when securing the RF package to the base plate or heat sink using one or more fasteners or bolts. The cover includes structural features to improve preferential deformation when a mounting force is applied. | 05-19-2011 |
| 20110080117 | DISTRIBUTED ARCHITECTURE VOLTAGE CONTROLLED BACKLIGHT DRIVER - 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. | 04-07-2011 |
| 20110062311 | CIRCUIT AND METHOD FOR TEMPERATURE AND PROCESS INDEPENDENT TRANSIMPEDANCE AMPLIFIER ARRANGEMENT - An integrated circuit transimpedance amplifier arrangement constituted of: a plurality of internal matched resistors; a current multiplier arranged to output a signal whose value is a function of an input current signal, an external resistor and a first set of the plurality of internal matched resistors; and an output transimpedance amplifier coupled to the output of the current multiplier, the output transimpedance amplifier exhibiting a gain whose value is a function of a second set of the plurality of internal matched resistors, wherein the output of the output transimpedance amplifier is a function of the input current signal, the external resistor, the first set of the plurality of internal matched resistors and the second set of the plurality of internal matched resistors, wherein the variations with temperature of the first set of the plurality of internal matched resistors and the second set of the plurality of internal matched resistors cancel. | 03-17-2011 |
| 20110049532 | SILICON CARBIDE DUAL-MESA STATIC INDUCTION TRANSISTOR - A dual-mesa static induction transistor (SIT) structure includes a silicon carbide substrate having a layer arrangement formed thereon. Laterally spaced ion implanted gate regions are defined in the layer arrangement. Source regions are defined in the layer arrangement. Each of the source regions can include a channel mesa having a source mesa disposed thereon. The source mesa includes sidewalls relative to a principal plane of the substrate defining a horizontal dimension thereof. The channel mesa includes slanted sidewalls relative to the source mesa and the principal plane of the substrate. Also disclosed is a method of fabricating a dual-mesa SiC transistor device. The method includes implanting ions at a normal relative to a principal plane of the substrate to form gate junctions in upper portions of the substrate and lateral portions of the slanted channel mesas. | 03-03-2011 |
| 20110037139 | SCHOTTKY BARRIER DIODE (SBD) AND ITS OFF-SHOOT MERGED PN/SCHOTTKY DIODE OR JUNCTION BARRIER SCHOTTKY (JBS) DIODE - A merged PN/Schottky diode is provided having a substrate of a first conductivity type and a grid of doped wells of the second conductivity type embedded in the substrate. A Schottky barrier metal layer makes a Schottky barrier contact with the surface of the substrate above the grid. Selected embedded wells in the grid may make electrical contact to the Schottky bather metal layer, while most embedded wells do not. The diode forward voltage drop is reduced for the same diode area with reverse blocking benefits similar to a conventional JBS structure. | 02-17-2011 |
| 20110006232 | LOW VOLTAGE DROP CLOSED LOOP UNIDIRECTIONAL ELECTRONIC VALVE - A low voltage drop unidirectional electronic valve constituted of: a first terminal; a second terminal; a first electronically controlled switch coupled between the first terminal and the second terminal; and a first charge pump arranged to close the first electronically controlled switch when the voltage potential at the first terminal is greater than the voltage potential at the second terminal by a first value. The first charge pump is arranged in a closed loop with the first electronically controlled switch so as to continuously maintain the voltage potential at the first terminal greater than the voltage potential at the second terminal by the first value. | 01-13-2011 |
| 20100327761 | INTEGRATED BACKLIGHT CONTROL SYSTEM - A lighting arrangement constituted of: a power factor correction circuit; a lighting controller operative at an electrical potential consonant with the electric potential of the output of the power factor correction circuit; a switching network, coupled to the output of the power factor correction circuit and to respective outputs of the lighting controller; a transformer, a primary winding of the transformer coupled to the output of the switching network; and at least one luminaire coupled to at least one secondary winding of the transformer and arranged to be driven by the at least one secondary winding, the lighting controller operative to control the switching network via the respective outputs to switchably pass current from the power factor correction circuit through the primary winding, thereby powering the at least one luminaire. | 12-30-2010 |
| 20100277125 | BATTERY CHARGING AND DISCHARGING BY USING A BI-DIRECTIONAL TRANSISTOR - A battery charger for an electronic device receives current limited power from an external power source, such as a Universal Serial Bus power interface. The battery charger can linearly regulate a charging current to an internal battery and limit the charging current so as not to demand current in excess of what the external power source can provide. A bi-directional pass element coupled between a system power terminal and the internal battery controls the charging current and effectively isolates the internal battery from a system load during charging of the battery while providing a low impedance path from the internal battery to the system load during discharging of the battery. | 11-04-2010 |
| 20100245001 | COAXIAL-TO-MICROSTRIP TRANSITIONS - Coaxial-to-microstrip transitions may include a microstrip line and coaxial-line assembly. The microstrip line includes a first dielectric having an aperture, a conductive strip disposed on one primary face of the first dielectric, and a ground plane disposed on the opposite primary face of the first dielectric. The coaxial-line assembly includes an outer conductor and an inner conductor. In some examples, the ground plane extends between the outer conductor and the inner conductor on a first side of the coaxial-line assembly proximate the conductive strip and an aperture cross section extends beyond the outer conductor on a second side of the coaxial-line assembly distal the conductive strip. In some examples, the ground plane has a non-circular aperture. In some examples, the outer conductor encloses an area that is less than an area of the aperture. In some examples, the enclosed area has a width that is less than a corresponding width of the first aperture. | 09-30-2010 |
| 20100237836 | METHOD AND APPARATUS FOR MODIFYING RIGHT HALF-PLANE ZERO IN A CASCADED DC-DC BUCK-BOOST CONVERTER - A method to generate a substantially DC output having a voltage level different than a DC input, constituted of receiving a feedback signal representing at least one of the voltage level and the current level of the generated substantially DC output; relatively emphasizing the high frequency portion of the feedback signal; controlling the buck function of a cascaded buck-boost converter with a first switching signal having a first duty cycle, the first duty cycle being a first function of the received feedback signal responsive to said relatively emphasized high frequency portion; and controlling the boost function with a second switching signal having a second duty cycle, the second duty cycle being a second function of the received feedback signal, wherein the first switching signal and the second switching signal are continuously enabled to facilitate a continuous conduction mode. | 09-23-2010 |
| 20100176657 | FOUR QUADRANT MOSFET BASED SWITCH - An electronically controlled four quadrant MOSFET based switch in which a pair of drivers are provided in cooperation with a MOSFET. A first one of the drivers is arranged such that when current flow through the MOSFET is to be enabled responsive to a first condition of the control signal, the gate of the MOSFET is driven with an appropriate voltage, and when current flow through the MOSFET is to be disabled responsive to a second condition of the control signal, the gate is driven towards a limit voltage. A second one of the drivers is arranged such that when current flow through the MOSFET is to be enabled the body diode connection of the MOSFET is driven towards the potential of the MOSFET source, and when current flow through the MOSFET is to be disabled the body diode connection is driven towards the limit voltage. | 07-15-2010 |
| 20100123400 | METHOD AND APPARATUS FOR DRIVING CCFL AT LOW BURST DUTY CYCLE RATES - A cold cathode fluorescent lamp controller constituted of a pulse generator exhibiting a cycle period; a burst dimming control operative to set a burst dimming duty cycle for the pulse generator; a comparator arranged to receive a signal indicative of the value of current through a load driven by the pulse generator and compare the received signal to a reference signal; an error detection circuit operative to shut down the pulse generator responsive to an output of the comparator indicating that the received signal is less than the reference signal for a predetermined number of cycles of the pulse generator; and a disable circuit arranged to prevent, when the set burst dimming duty cycle is less than a predetermined value, the shut down of the pulse generator responsive to the output of the comparator indicating the received signal is less than the reference signal. | 05-20-2010 |
| 20100090611 | FULL-BRIDGE AND HALF-BRIDGE COMPATIBLE DRIVER TIMING SCHEDULE FOR DIRECT DRIVE BACKLIGHT SYSTEM - A driver circuit or controller flexibly drives either a half-bridge or a full-bridge switching network in a backlight inverter without modification, redundant circuitry or additional components. The driver circuit includes four outputs to provide four respective driving signals that establish a periodic timing sequence using a zero-voltage switching technique for semiconductor switches in the switching network. | 04-15-2010 |
| 20090289569 | CCFL CONTROLLER WITH MULTI-FUNCTION TERMINAL - A cold cathode fluorescent lamp controller exhibiting a multi-function terminal and operative alternately in a strike mode and a run mode, the controller comprising: a phase locked loop arranged for synchronization of an oscillator, associated with the controller, with an external signal, the phase locked loop comprising a capacitor coupled to the multi-function terminal; and a soft start circuit arranged to limit drive current immediately after reset of the controller responsive to a signal at the multi-function terminal. In one embodiment the controller further comprises an error detection circuit arranged to output an error signal on the multi-function terminal. In one embodiment the controller further comprises a frequency sweeping circuit operative to sweep the frequency of a drive signal during the strike mode of the controller, the frequency of the drive signal being swept by the frequency sweeping circuit responsive to a signal at the multi-function terminal. | 11-26-2009 |
| 20090273295 | STRIKING AND OPEN LAMP REGULATION FOR CCFL CONTROLLER - An apparatus and method for igniting a lamp during a strike mode of an inverter comprising: sequentially controlling a duty cycle sweep and a frequency sweep of driving signals in the inverter to provide an increasing output voltage to the lamp. One embodiment advantageously includes a closed feedback loop to implement the duty cycle sweep and the frequency sweep such that an open lamp voltage is reliably regulated during the strike mode. For example, the closed feedback loop stops the duty cycle sweep or the frequency sweep when the output voltage to the lamp reaches a predetermined threshold and makes adjustments to the duty cycle or frequency the driving signals as needed to keep the output voltage at approximately the predetermined threshold if the lamp has not ignited. | 11-05-2009 |
| 20090267521 | BALANCING TRANSFORMERS FOR MULTI-LAMP OPERATION - A ring balancer comprising a plurality of balancing transformers facilitates current sharing in a multi-lamp backlight system. The balancing transformers have respective primary windings separately coupled in series with designated lamps and have respective secondary windings coupled together in a closed loop. The secondary windings conduct a common current and the respective primary windings conduct proportional currents to balance currents among the lamps. The ring balancer facilitates automatic lamp striking and the lamps can be advantageously driven by a common voltage source. | 10-29-2009 |
| 20090261471 | RF POWER TRANSISTOR PACKAGE - An RF power transistor package with a rectangular ceramic base can house one or more dies affixed to an upper surface of the ceramic base. Source leads attached to the ceramic base extend from at least opposite sides of the rectangular base beneath a periphery of a non-conductive cover overlying the ceramic base. The cover includes recesses arranged to receive the one or more die, the ceramic base, gate and drain leads and a portion of the source leads. The cover further includes bolt holes arranged to clamp the ceramic base and source leads to a heat sink. Bosses at corners of the cover outward of the bolt holes exert a downward bowing force along the periphery of the cover between the bolt holes. | 10-22-2009 |
| 20090212741 | BATTERY CHARGING AND DISCHARGING BY USING A BI-DIRECTIONAL TRANSISTOR - A battery charger for an electronic device receives current limited power from an external power source, such as a Universal Serial Bus power interface. The battery charger can linearly regulate a charging current to an internal battery and limit the charging current so as not to demand current in excess of what the external power source can provide. A bi-directional pass element coupled between a system power terminal and the internal battery controls the charging current and effectively isolates the internal battery from a system load during charging of the battery while providing a low impedance path from the internal battery to the system load during discharging of the battery. | 08-27-2009 |
| 20090206794 | LINEARLY REGULATED BATTERY CHARGER - A battery charger for an electronic device receives current limited power from an external power source, such as a Universal Serial Bus power interface. The battery charger can linearly regulate a charging current to an internal battery and limit the charging current so as not to demand current in excess of what the external power source can provide. A bi-directional pass element coupled between a system power terminal and the internal battery controls the charging current and effectively isolates the internal battery from a system load during charging of the battery while providing a low impedance path from the internal battery to the system load during discharging of the battery. | 08-20-2009 |
| 20090206767 | SPLIT PHASE INVERTERS FOR CCFL BACKLIGHT SYSTEM - An apparatus and method for driving a lamp are provided. In one embodiment, an inverter having four switching elements is split into two inverter arms that are deployed at separate terminals of a floating lamp structure to achieve even light output. A controller drives both inverter arms such that power switching lines do not cross the floating lamp structure. In one embodiment, the controller adjusts the brightness of the lamp structure by adjusting the phase difference between outputs of a first inverter arm relative to a second inverter arm. In one embodiment, the controller adjusts the brightness by symmetrically pulse width modulating the outputs of the first inverter arm and the second inverter arm. | 08-20-2009 |
| 20090195178 | BALANCING ARRANGEMENT WITH REDUCED AMOUNT OF BALANCING TRANSFORMERS - A backlighting arrangement constituted of: a driving transformer; at least one balancing transformer; a plurality of luminaires, a first end of each of the plurality of luminaires connected to a high voltage lead of the driving transformer and a second end of each of the plurality of luminaires connected to a unique end of a winding of the at least one balancing transformer, wherein each pair of the luminaires is associated with a particular winding of one of the at least one balancing transformers, and wherein the first end and the second end of each of the luminaires is in physical proximity of the driving transformer and the at least one balancing transformer, the constituent lamps of the luminaires arranged in parallel and generally extending axially away from the proximity of the driving transformer. | 08-06-2009 |
| 20090195175 | Direct Coupled Balancer Drive For Floating Lamp Structure - A backlighting arrangement constituted of a driving transformer arrangement; a plurality of lamp pairs, each of the constituent lamps of the plurality of lamp pairs exhibiting a first electrical connection and a second electrical connection; and a plurality of balancing transformers, each comprising a primary winding and a secondary winding magnetically coupled to the primary winding, and each associated with a particular one of the plurality of lamp pairs, the primary winding of each of the plurality of balancing transformers serially connected between the second electrical connections of the constituent lamps of the associated lamp pair, the secondary windings of the plurality of balancing transformers serially connected in phase, with a first end of the serially connected secondary windings of the balancing transformers connected to one phase output of the driving transformer arrangement. | 08-06-2009 |
| 20090195174 | ARRANGEMENT SUITABLE FOR DRIVING FLOATING CCFL BASED BACKLIGHT - A backlighting arrangement constituted of: a means for receiving an alternating current comprising a first lead and a second lead; at least one luminaire; and at least one first balancing transformer pair each associated with a particular one of the at least one luminaire, the primary of a first balancing transformer of the first balancing transformer pair serially coupled between the first lead of the means for receiving an alternating current and a first end of each of the at least one luminaire, and the primary of a second balancing transformer of the first balancing transformer pair serially coupled between the second lead of the means for receiving an alternating current and a second end of each of the at least one luminaires The secondaries of all of the at least one first balancing transformer pair are serially connected in a closed in-phase loop. | 08-06-2009 |
| 20090195163 | Single LED String Lighting - A solid state lighting unit constituted of: a control circuitry; a single string of light emitting diodes, the single string constituted of a plurality of sections each comprising a plurality of light emitting diodes; and a plurality of bypass paths each responsive to the control circuitry, each of the plurality of bypass paths arranged to provide bypass to a particular one of the plurality of sections, wherein the control circuitry is operative to identify an open circuit condition of a particular one of the plurality of sections, and activate the bypass path arranged to bypass the open circuit section, thereby providing light through sections not exhibiting an open circuit condition. | 08-06-2009 |
| 20090184746 | Low Voltage Drop Unidirectional Electronic Valve - A low voltage drop unidirectional electronic valve constituted of: a first terminal; a second terminal; an electronically controlled switch arranged to allow the flow of current from the first terminal to the second terminal when closed, the electronically controlled switch comprising a pair of reverse serially connected field effect transistors; a control circuit, arranged to close the electronically controlled switch responsive to the potential of the first terminal exceeding the potential of the second terminal by a predetermined amount; and a refresh circuit arranged to periodically open the electronically controlled switch. In one embodiment the low voltage drop unidirectional valve is arranged as one of a solar bypass element and an ORing diode. | 07-23-2009 |
| 20090160422 | BOOST CONVERTER WITH ADAPTIVE COIL PEAK CURRENT - A power conversion circuit operates in a discontinuous switching mode over a wide range of loading conditions and varies a coil peak current to maintain efficiency over the wide range of loading conditions. The coil peak current is adjustable based at least in part on a feedback signal generated in response to a load condition. | 06-25-2009 |
| 20090154543 | Using a Triangular Waveform to Synchronize the Operation of an Electronic Circuit - An electronic circuit exhibiting synchronization with an external synchronization signal, the electronic circuit comprising: an input connection arranged to receive a synchronization input signal; a triangular waveform oscillator operatively associated with the synchronization signal input connection and responsive to a condition of the received synchronization input signal to initiate a triangular waveform; and a pulse train generator operatively associated with the triangular waveform oscillator, the pulse train generator arranged to generate a plurality of pulse trains having a fixed non-zero phase relationship between them and a frequency responsive to the condition of the synchronization input signal. | 06-18-2009 |
| 20090091560 | METHOD AND APPARATUS TO CONTROL DISPLAY BRIGHTNESS WITH AMBIENT LIGHT CORRECTION - An ambient light sensor produces a current signal that varies linearly with the level of ambient light. The current signal is multiplied by a user dimming preference to generate a brightness control signal that automatically compensates for ambient light variations in visual information display systems. The multiplying function provides noticeable user dimming control at relatively high ambient light levels. | 04-09-2009 |
| 20090072340 | EDGE TERMINATION FOR HIGH VOLTAGE SEMICONDUCTOR DEVICE - High voltage semiconductor devices with high-voltage termination structures are constructed on lightly doped substrates. Lightly doped p-type substrates are particularly prone to depletion and inversion from positive charges, degrading the ability of associated termination structures to block high voltages. To improve the efficiency and stability of termination structures, second termination regions of the same dopant type as the substrate, more heavily doped than the substrate but more lightly doped than first termination regions, are positioned adjoining the first termination regions. The second termination regions raise the field threshold voltage where the surface is vulnerable and render the termination structure substantially insensitive to positive charges at the surface. The use of higher dopant concentration in the gap region without causing premature avalanche is facilitated by only creating second termination regions for regions lacking field plate protection. | 03-19-2009 |
