Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: Methods of constructing silicon carbide semiconductor devices in a self-aligned manner. According to one aspect of the invention, the method may include forming a mesa structure in a multi-layer laminate including at least a first and second layer of silicon carbide material. The mesa structure may then be utilized in combination with at least one planarization step to construct devices in a self-aligned manner. According to another aspect of the present invention, the mesa structure may be formed subsequent to an ion implantation and anneal steps to construct devices in a self-aligned manner. According to another aspect of the present invention, a high temperature mask capable of withstanding the high temperatures of the anneal process may be utilized to form devices in a self-aligned manner.

Abstract: 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.

Abstract: Disclosed are a variety of junction termination structures for high voltage semiconductor power devices. The structures are specifically aimed at providing a high breakdown voltage while being constructed with a minimal number of process steps. The combination of an RIE etch and/or implantation and anneal process with a finely patterned mesh provides the desired radial gradient for maximum breakdown voltage. The structures provide control of both the conductivity and charge density within the region. These structures can beneficially be applied to all high voltage semiconductor device structures, but are of particular interest for wide bandgap devices as they tend to have very high breakdown fields and scaled dimensions of the depletion layer width.

Abstract: This invention relates to a novel optoelectronic chip with one or more optoelectronic devices, such as photodiodes, fabricated on a front side of a semiconductor wafer and contacts on a backside of the semiconductor wafer. The backside contacts can be contact bumps, which allow the optoelectronic chip to achieve the benefits of flip chip packaging without flipping the optoelectronic chip upside down with respect to a chip carrier. In an optical communication system, a photodiode chip can be backside bumped to a chip carrier or an electronic chip, allowing front side illumination of the photodiode chip. Front side illumination offers many benefits, including improved fiber alignment, reduced manufacturing time, and overall cost reduction.

Abstract: 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.

Abstract: A method of powering from a power sourcing equipment to a powered device over communication cabling, the method comprising: determining the effective resistance between a power sourcing equipment and a powered device; determining the length of communication cabling between the power sourcing equipment and the powered device; calculating a metric of the constituent wires of the communication cabling between the power sourcing equipment and the powered device responsive to the determined effective resistance and the determined length of communication cabling; and setting current limits for the powering of the powered device from the power sourcing equipment responsive to the calculated metric. In one embodiment the metric is one of a cross-sectional, an effective resistance per unit length and a current carrying capability of the constituent wires.

Abstract: An electronic package designed to package silicon carbide discrete components for silicon carbide chips. The electronic package allows thousands of power cycles and/or temperature cycles between ?55° C. to 300° C. The present invention can also tolerate continuous operation at 300° C., due to high thermal conductivity which pulls heat away from the chip. The electronic package can be designed to house a plurality of interconnecting chips within the package. The internal dielectric is able to withstand high voltages, such as 1200 volts, and possibly up to 20,000 volts. Additionally, the package is designed to have a low switching inductance by eliminating wire bonds. By eliminating the wire bonds, the electronic package is able to withstand an injection mold.

Abstract: A current-mode switching regulator uses a slope compensation circuit that automatically accounts for different inductor values and varying input voltages to generate a slope compensation signal. The slope compensation circuit monitors a voltage across a semiconductor switch to extract an upslope signal that tracks increasing inductor current in the current-mode switching regulator. The slope compensation signal is generated based on the upslope signal and a difference between an input voltage and an output voltage of the current-mode switching regulator.

Abstract: A controller for an inverter provides variable gain control in a voltage regulation loop to prevent overshoot in an output voltage of the inverter. A feedback circuit senses the output voltage and provides a voltage feedback signal to the controller. The controller includes a voltage conversion circuit and an error amplifier as part of the voltage regulation loop. A gain control block varies a circuit parameter in the voltage conversion circuit or the error amplifier such that regulation of the output voltage starts at a relatively lower voltage level and increases smoothly to a desired level.

Abstract: A lamp inverter with continuous strike voltage facilitates faster striking of a fluorescent lamp, especially at cold temperatures. A frequency sweep generator sweeps the frequency of the lamp inverter to a striking frequency corresponding to a striking lamp voltage and then maintains the striking frequency until the lamp strikes.

Abstract: An illumination control circuit allows a user to set a desired brightness level and maintains the desired brightness level over temperature and life of a light source. The illumination control circuit uses a dual feedback loop with both optical and thermal feedbacks. The optical feedback loop controls power to the light source during normal operations. The thermal feedback loop overrides the optical feedback loop when the temperature of the light source becomes excessive.

Abstract: An efficient ramp generator uses a reversing switch array to couple a timing capacitor in alternating polarities between an input terminal and an output terminal of an operational amplifier to generate a periodic ramp signal without discharging the timing capacitor between voltage ramps. The reversing switch array includes at least four semiconductor switches controlled by a flip-flop circuit or a latch circuit. The flip-flop circuit or the latch circuit can be driven by an external clock signal or an internal clock signal with a variable frequency.

Abstract: 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.

Abstract: A feed-forward correction circuit in a PWM controller adjusts an error signal inversely with respect to a supply voltage for a switching voltage regulator to quickly compensate for changes or transients in the supply voltage. The adjusted error signal is provided to a PWM comparator to control a duty cycle of an output signal. The switching voltage regulator can be a DC-to-DC converter or a DC-to-AC converter, and the output signal is used to generate one or more driving signals to control semiconductor switches in the switching voltage regulator. The feed-forward correction circuit uses an offset compensation technique or a translinear circuit to maintain a substantially inverse product relationship between the supply voltage and the duty cycle of the output signal, thereby reducing overshoots and undershoots in a regulated output voltage of the switching voltage regulator.

Abstract: A SiC die with Os and/or W/WC/TiC contacts and metal conductors is encapsulated either alone or on a ceramic substrate using a borosilicate (BSG) glass that is formed at a temperature well below upper device operating temperature limits but serves as a stable protective layer above the operating temperature (over 1000° C., preferably >1200° C.). The glass is preferably 30-50% B2O3/70-50% SiO2, formed by reacting a mixed powder, slurry or paste of the components at 460°-1000° C. preferably about 700° C. The die can be mounted on the ceramic substrate using the BSG as an adhesive. Metal conductors on the ceramic substrate are also protected by the BSG. The preferred ceramic substrate is AIN but SiC/AIN or Al2 03 can be used.

Abstract: 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.