Atmel Corporation

Siliconsystems, Inc.

National Semiconductor Corporation

Other

Monolithic Power Systems, Inc.

Microchip Technology Inc.

Maxim Integrated Products, Inc.

Amtel Corporation

Siemens Power Transmission & Distribution, Inc.

Jeff Kotowski

Charles Cai

Timothy James Herklots

Richard D Davis

Sean S Chen

Danut Manea

William James McIntyre

Yongliang Wang

Ranajit Ghoman

John Philip Parry

Scott N Fritz

John T Voisine

Shane Charles Hollmer

Andre Gunther

Urs H Mader

Kien Vi

Gordon R Burns

Franco Cocetta

John P Junker

James Charles Schmoock

Qizhang Yin

Xiaoying Yu

Javier Adame

Ron Gangemi

Yvonne Ko

A bias circuit may generate a one or more bias outputs for a crystal oscillator. The bias circuit may include a first current mirror, a second current mirror and a third current mirror. A capacitor may be coupled between the second current mirror and the third current mirror. In operation, a first bias output may be generated by the third current mirror, and a second bias output may be generated by the second current mirror. The first bias output and second bias output may be coupled to a crystal oscillator.

Bias circuit for crystal oscillator

Systems and methods for controlling small grids of appliances are described. One sample method includes receiving consumption data from a plurality of electrical appliances that are plugged into outlets at a first location and monitoring power usage at the first location. The method includes evaluating the received consumption data to identify one or more predetermined conditions in one or more of the plurality of electrical appliances and evaluating stored data related to power consumption preferences at the first location. The power consumption preferences define conditions when a consumer associated with the first location has agreed to enable remote control of at least one designated appliance upon an occurrence of one or more predetermined conditions. The method includes determining that the one or more conditions are satisfied and to provide a first secure communication to the first appliance to control the power consumption.

Smart grid appliance control

Embodiments disclosed herein describe a solar panel protection and control system. The system can bypass the solar panel under hazardous conditions or under command. The system can also help a solar panel array to reach its maximum power point in operation.

Method and apparatus for solar panel protection and control system

A power converter is disclosed that includes an active valley fill (AVF) capacitor that is actively switched to provide current to a load during a portion of an alternating current (AC) input cycle. The current supplied to the load includes some current supplied by the AC input and some current supplied by the AVF capacitor. Circuitry is configured to regulate the amount of current flowing through the load, including controlling the amount of current supplied by the AVF capacitor. The duty cycle on the AVF capacitor can be adjusted to shape the AC input current waveform.

Active valley fill power factor correction

In a bandgap voltage reference with low package shift, a proportional to absolute temperature (PTAT) voltage is generated using a single diode biased at two different current levels at two different times. Using the same diode for both current density measurements removes the absolute value of the base-emitter junction voltage (Vbe) and any package shift in the PTAT voltage. The bandgap voltage reference can be implemented in a single or differential circuit topology. In some implementations, the bandgap voltage reference can include circuitry for curvature correction.

Voltage reference with low sensitivty to package shift

In one embodiment, a method includes displaying an input tool comprising a first touch icon and a first input icon. The first touch icon may be visually separated from the first input icon by a predetermined distance. The first input icon may provide a graphical indication of an input associated with the first touch icon. The method may include determining an input based on a touch at or substantially near a location on a touch sensor associated with the first touch icon. The method may also include effecting the input as determined.

Touch sensor input tool with offset between touch icon and input icon

A color correcting device driver is configured to vary the equivalent current into light emitting elements (e.g., LEDs) with the frequency of the AC input current (e.g., 120 Hz). In implementations that include a fly-back controller with a power factor correction (PFC) controller on the primary side, the color correcting device driver performs the method of: 1) turning on the loads (e.g., white and CA strings of LEDs); 2) determining if the voltage supplied to the loads has dropped by a first threshold amount; 3) turning off the loads; and 4) determining if the voltage supplied to loads has recovered by a second threshold amount (or waiting for a fixed amount of time). The method is repeated. In implementations that do not include a PFC controller on the primary side, the color correcting device driver can create a pulse width modulated (PWM) signal.

Color correcting device driver

In one novel aspect, driving a string of light emitting elements, such as LEDs, includes applying a drive signal to circuitry that regulates a voltage appearing at a source of a transistor whose drain is coupled to one end of the string of light emitting elements and whose source is coupled to ground through a resistive element. Sequencing of the drive signal and a voltage supply signal for the light emitting elements is controlled such that the voltage supply signal is not increased above a predetermined allowable voltage for the transistor until the transistor is turned on, and such that the supply voltage is not decreased below the allowable voltage for the transistor until the transistor is turned off.

Circuit for driving light emitting elements

Voltage reference with low sensitivity to package shift

The disclosed multi-channel driver equalizer circuit matches currents in multiple strings of illumination devices at low current levels by using an analog equalizer to sequentially couple the output of a reference amplifier in series with each current source amplifier in a current limit loop of the driver equalizer circuit to correct the offsets of the current source amplifiers, resulting in the matching of string currents on average.

Multi-channel driver equalizer

A power conversion circuit of two feedback loops is disclosed that includes a feedback control circuit for ramping up or down a commanded voltage to a load (e.g., LEDs). The second feedback loop feeds into the first feedback loop, and the second feedback loop operates at a slower bandwidth than the first feedback loop. When ramping up or down the commanded voltage, a voltage overshoot results because of delay in the system. The overshoot can be compensated for by a final adjustment to the commanded voltage.

Power conversion feedback control circuit for reaching a goal voltage

A primary side PFC driver circuit is disclosed that includes a switch control circuit for commanding a switch to allow an inductor coupled to an output load (e.g., LEDs) to transfer energy provided by an input voltage source. The switch control circuit provides two signals for commanding the switch. A first signal having a first frequency, with a duty cycle in proportion to the input voltage amplitude, commands the switch to allow the average input current to be proportional to the input voltage amplitude. A second signal having a second frequency higher than the first frequency pulses the output load with substantially constant current pulses based on a value of the first signal (e.g., while the first signal is high). The current pulses produce a substantially constant current in the output load.

Primary side PFC driver with dimming capability

A reference voltage circuit corrects for bandgap voltage shifts induced during fabrication. The reference voltage circuit generates a reference voltage using first and second base-emitter pairs. The reference voltage circuit sums the voltage across the first base-emitter pair with a difference voltage. During a first time period, the difference voltage is the voltage across the first base-emitter pair minus the voltage across the second base-emitter pair, and during a second time period, the difference voltage is the voltage across the second base-emitter pair minus the voltage across the first base-emitter pair.

Reference voltage circuits

The disclosed implementations utilize the voltage drop inherent in the device string to power a device control IC. In some implementations, current is drawn from the bottom of the device string and applied to a voltage supply pin of the device control IC. In some implementations, current is drawn from some other location in the device string (e.g., near the bottom or midpoint of the device string) using a switch. In some implementations, current is drawn from near the bottom and the bottom of the device string at different times, such that less current is drawn from the bottom of the device string as the duty cycle of the device string increases and more current is drawn from near the bottom of the device string as the duty cycle of the device string increases.

Growing community of inventors

Nevada City, CA, United States of America

Jeff Kotowski