Patent application number | Description | Published |
20080290813 | Electronically controlling acoustic energy from piezoelectric transformers - A power-supply circuit is described. In particular, the power-supply circuit includes an input node configured to receive a power-supply signal, an output node configured to output a modulated power-supply signal, and a modulation mechanism coupled between the input node and the output node. This modulation mechanism is configured to modulate the power-supply signal to produce the modulated power-supply signal. Furthermore, the modulation mechanism may be configured to modulate the power-supply signal using both a first modulation and a second modulation. This first modulation is a duty-cycle modulation which controls the power output of the piezoelectric transformer signal, and the second modulation spreads harmonic energy associated with the first modulation over a range of frequencies. By spreading the harmonic energy, the perceived acoustical noise generated by the piezoelectric transformer is reduced. | 11-27-2008 |
20090079746 | SWITCHING BETWEEN GRAPHICS SOURCES TO FACILITATE POWER MANAGEMENT AND/OR SECURITY - One embodiment of the present invention provides a system that switches between frame buffers which are used to refresh a display. During operation, the system refreshes the display from a first frame buffer which is located in a first memory. Upon receiving a request to switch frame buffers for the display, the system reconfigures data transfers to the display so that the display is refreshed from a second frame buffer which is located in a second memory. | 03-26-2009 |
20090138225 | METHODS AND APPARATUSES FOR CALIBRATING SENSORS - Methods and apparatuses to perform calibration of imprecise sensors for power monitoring in a data-processing system are described. The system includes a load coupled to one or more sensors. An electronic load changes a first input signal through one or more sensors by a predetermined amount. A difference in an output signal from the one or more sensors in response to the changing is obtained. The output signal is measured and sampled. A distribution of samples of the output signal is determined. The estimated parameters of the distribution that most likely to explain actual data are determined. Next, a transfer function of the one or more sensors is determined based on the estimated parameters. The input signal through the load is accurately predicted using the transfer function of the one or more sensors to monitor the power usage by the load. | 05-28-2009 |
20090138745 | Electronic devices with radio-frequency collision resolution capabilities - Electronic devices such as portable electronic devices contain electronic components. The electronic components may include radio-frequency transceiver circuitry. The radio-frequency transceiver circuitry may be used for handling data communications and cellular telephone voice communications. One or more adjustable clock sources may be provided within the electronic device. The adjustable clock sources may be based on phase-locked-loop circuits. A clock manager may determine which frequencies are being used by the radio-frequency transceiver circuitry and other components in the electronic device. The clock manager may use this information to compute a list of safe fundamental clock signal frequencies. Based on the list of safe clock signal frequencies, the clock manager may dynamically adjust the clock sources to avoid collisions between harmonics of the clock signals from the clock sources and the frequencies used by the transceiver circuitry and other components. | 05-28-2009 |
20090237415 | ANTI-PHASE PULSE WIDTH MODULATOR - A method and system is disclosed for modifying the pulse width modulation signal frequency for controlling the backlight illumination intensity of a liquid crystal display. The modified pulse width modulation signal frequency is selected to eliminate visible light and dark bands in the liquid crystal display image. The brightness of the display may be also adjusted by modifying the duty cycle of the pulse width modulation signal. The brightness selected, either automatically or by the user, is matched with a pulse width modulation signal frequency to insure that the pulse width modulation signal will be anti-phased across a plurality of contiguous frame refresh periods. | 09-24-2009 |
20090256528 | DIFFUSION-LIMITED ADAPTIVE BATTERY CHARGING - Some embodiments of the present invention provide a system that adaptively charges a battery, wherein the battery is a lithium-ion battery which includes a transport-limiting electrode governed by diffusion, an electrolyte separator and a non-transport-limiting electrode. During operation, the system determines a lithium surface concentration at an interface between the transport-limiting electrode and the electrolyte separator based on a diffusion time for lithium in the transport-limiting electrode. Next, the system calculates a charging current or a charging voltage for the battery based on the determined lithium surface concentration. Finally, the system applies the charging current or the charging voltage to the battery. | 10-15-2009 |
20090259420 | ADAPTIVE SURFACE CONCENTRATION BATTERY CHARGING - Some embodiments of the present invention provide a system that adaptively charges a battery, wherein the battery is a lithium-ion battery which includes a transport-limiting electrode, an electrolyte separator and a non-transport-limiting electrode. To charge the battery, the system first determines a lithium surface concentration at an interface between the transport-limiting electrode and the electrolyte separator. Next, the system uses the determined lithium surface concentration to control a charging process for the battery so that the charging process maintains the lithium surface concentration within set limits. | 10-15-2009 |
20090273320 | CONTROLLING BATTERY CHARGING BASED ON CURRENT, VOLTAGE AND TEMPERATURE - Some embodiments of the present invention provide a system that charges a lithium-ion battery. During operation, the system monitors: a current through the battery, a voltage of the battery, and a temperature of the battery. Next, the system uses the monitored current, voltage and temperature to control a charging process for the battery. In some embodiments, controlling the charging process involves: inferring electrode lithium surface concentrations for the battery from the monitored current, voltage and temperature; and applying the charging current and/or the charging voltage in a manner that maintains the inferred electrode lithium surface concentrations for the battery within set limits. | 11-05-2009 |
20090313484 | METHOD AND APPARATUS FOR PROLONGING BATTERY LIFE OF A MEDIA PLAYER - A method of operating a media player is provided. In one embodiment the method includes receiving a plurality of initially configured video settings for viewing a video segment on the media player for a desired playback duration. The method further includes determining power required to play the video segment based on the initial video settings and playing the video segment if the required power matches or is less than total power available to the media player. In another embodiment, the method may further include, if the required power exceeds the total power available to the media player, adjusting one or more of the initial video settings, either automatically or by user inputs, to reduce the power required to play the requested video segment for the desired playback duration. | 12-17-2009 |
20090325056 | PARALLEL BATTERY ARCHITECTURE WITH SHARED BIDIRECTIONAL CONVERTER - Some embodiments provide a system that provides a power source. The power source includes a set of cells and a main power bus configured to connect the set of cells in a parallel configuration. The power source also includes a bidirectional converter configured to connect to one cell from the set of cells at a time. Finally, the power source includes a set of switches configured to switch each cell in the set of cells to one of the main power bus and the bidirectional converter. | 12-31-2009 |
20100091691 | Dynamic thermal control for wireless transceivers - Methods and apparatus for dynamic thermal management and control within, e.g., small form-factor wireless devices such as laptop computers or cellular “smartphones”. In one embodiment, a thermal management system monitors the temperature (or other relevant criteria) for one or more components, and implements different operating states within the wireless transceiver (e.g., Wi-Fi™ or WiMAX transceiver) so as to both reduce thermal output and minimize disruption to the wireless link and/or user experience. In another embodiment, a wireless client may communicate with other clients, and/or access points, so as to cooperatively provide more options for thermal management. In addition, methods and apparatus employing “high performance” (e.g., high power output or high data rate) radios within aggressively small industrial designs are also disclosed. | 04-15-2010 |
20100091747 | Dynamic thermal control for wireless transceivers - Methods and apparatus for dynamic thermal management and control within, e.g., small form-factor wireless devices such as laptop computers or cellular “smartphones”. In one embodiment, a thermal management system monitors the temperature (or other relevant criteria) for one or more components, and implements different operating states within the wireless transceiver (e.g., Wi-Fi™ or WiMAX transceiver) so as to both reduce thermal output and minimize disruption to the wireless link and/or user experience. In another embodiment, a wireless client may communicate with other clients, and/or access points, so as to cooperatively provide more options for thermal management. In addition, methods and apparatus employing “high performance” (e.g., high power output or high data rate) radios within aggressively small industrial designs are also disclosed. | 04-15-2010 |
20100308770 | METHOD AND SYSTEM FOR CHARGING A SERIES BATTERY - Some embodiments of the present invention provide a system for charging a series battery, wherein the series battery is comprised of a set of banks which are connected in series, so that the same charging current passes through each bank. During the charging process, the system measures a voltage across each bank in the set of banks. The system then compares the measured voltage with a target voltage for each bank, and adjusts the charging process based on results of the comparisons between the measured voltage and the target voltage. | 12-09-2010 |
20110031956 | HIGH-EFFICIENCY, SWITCHED-CAPACITOR POWER CONVERSION - Some embodiments of the present invention provide a system that efficiently converts between a lower input voltage and a higher output voltage. This system includes an input which receives the input voltage, and an output which provides the output voltage. The system also includes a first capacitor with a higher potential terminal and a lower potential terminal, as well as a first set of switching devices which selectively couple the higher potential and lower potential terminals of the first capacitor between the input voltage, the output voltage and a base voltage. The system additionally includes a resonant clocking circuit which generates clock signals with substantially non-overlapping clock phases, including a first phase and a second phase. This resonant clocking circuit is configured to control the first set of switching devices so that during the first phase, the higher potential terminal of the first capacitor is coupled to the input voltage and the lower potential terminal of the first capacitor is coupled to the base voltage, and during the second phase, the higher potential terminal of the first capacitor is coupled to the output voltage and the lower potential terminal of the first capacitor is coupled to the input voltage. | 02-10-2011 |
20110031957 | CONTROLLING POWER LOSS IN A SWITCHED-CAPACITOR POWER CONVERTER - The disclosed embodiments relate to a system that implements a switched-capacitor power converter which is configured to actively control power loss while converting an input voltage to an output voltage. This system includes one or more switched-capacitor blocks (SCBs), wherein each SCB includes a first capacitor and a set of switching devices configured to couple a constant-potential terminal and a time-varying-potential terminal of the first capacitor between the input voltage, the output voltage and a reference voltage. The system also includes a clocking circuit which produces gate drive signals for switching transistors in the one or more SCBs. The system additionally includes a controller configured to actively control the gate drive signals from the clocking circuit to substantially minimize the power loss for the switched-capacitor power converter. | 02-10-2011 |
20110032042 | RESONANT OSCILLATOR WITH OSCILLATION-STARTUP CIRCUITRY - Some embodiments of the present invention provide a system that implements a resonant oscillator circuit. This system includes a first inductor with a constant potential terminal coupled to an input voltage, and a time-varying potential terminal coupled to a first phase output. The system also includes a second inductor with a constant potential terminal coupled to the input voltage, and a time-varying potential terminal coupled to a second phase output. The system additionally includes a first n-type transistor with a source terminal coupled to a base voltage, a drain terminal coupled to the first phase output, and a gate terminal coupled to the second phase output. The system also includes a second n-type transistor with a source terminal coupled to the base voltage, a drain terminal coupled to the second phase output, and a gate terminal coupled to the first phase output. Finally, the system includes a startup circuit configured to commence oscillations in the resonant oscillator circuit by energizing the first inductor before energizing the second inductor. | 02-10-2011 |
20110032043 | RESONANT OSCILLATOR CIRCUIT WITH REDUCED STARTUP TRANSIENTS - Some embodiments of the present invention provide a system that implements a resonant oscillator circuit. This resonant oscillator circuit includes: a first inductor, a second inductor, a first capacitance, and a second capacitance, wherein the first and second inductors are configured to operate with the first and second capacitances to produce resonant oscillations which appear at a first phase output and a second phase output. The system also includes a startup circuit which is configured to start the resonant oscillator circuit in a state where: the first phase output is at a peak voltage; the second phase output is at a base voltage; and currents through the first and second inductors are substantially zero. By starting the resonant oscillator circuit in this state, the oscillations commence without a significant startup transient. | 02-10-2011 |
20110298814 | SWITCHING VIDEO STREAMS FOR A DISPLAY WITHOUT A VISIBLE INTERRUPTION - The disclosed embodiments provide a system that facilitates driving a display in a computer system. During operation, the system receives an input video stream from a graphics source, wherein the input video stream comprises a sequence of video frames. Next, the system directs the input video stream through a set of two or more memory buffers including a front buffer and a back buffer to produce an output video stream, which is used to drive the display. While directing the input video stream through the set of memory buffers, the system writes a video frame from the input video stream into the back buffer, and concurrently drives the output video stream from a preceding video frame in the front buffer. When the writing of the video frame completes, the system switches buffers so that the back buffer becomes the front buffer, which drives the output video stream, and the front buffer becomes either a spare buffer or the back buffer, which receives a subsequent frame from the input video stream. | 12-08-2011 |
20120105162 | RESONANT OSCILLATOR WITH START UP AND SHUT DOWN CIRCUITRY - A system which starts up and shuts down a resonant oscillator circuit. During start up, the system operates a driving circuit, which is external to the resonant oscillator circuit, wherein the driving circuit uses a first clock signal to control a first phase output of the resonant oscillator circuit. At the same time, the driving circuit uses a second clock signal to control a second phase output of the resonant oscillator circuit, wherein the first and second clock signals have opposite phases. While the first and second phase outputs are being controlled, the system ramps up an input voltage, which is used to power the resonant oscillator circuit, wherein the ramping takes place across multiple initial oscillation periods. During shut down, the system shuts down the resonant oscillator circuit by ramping down the input voltage. Next, the system clamps the first and second phase outputs to a fixed voltage. | 05-03-2012 |
20120153728 | BALANCING VOLTAGES BETWEEN BATTERY BANKS - A system that balances voltages between battery banks. The system includes battery banks, including a first bank and a second bank, and a first capacitor. The system also includes a first set of switching devices which selectively couple first and second terminals of the first capacitor to first and second terminals of the first bank, and to first and second terminals of the second bank. The system includes a clocking circuit which generates clock signals with substantially non-overlapping first and second clock phases. This clocking circuit is configured so that during the first phase the first and second terminals of the first capacitor are coupled to the first and second terminals of the first bank, respectively, and during the second phase the first and second terminals of the first capacitor are coupled to the first and second terminals of the second bank, respectively. | 06-21-2012 |
20120153898 | METHOD AND SYSTEM FOR CHARGING A SERIES BATTERY - Some embodiments of the present invention provide a system for charging a series battery, wherein the series battery is comprised of a set of banks which are connected in series, so that the same charging current passes through each bank. During the charging process, the system measures a voltage across each bank in the set of banks. The system then compares the measured voltage with a target voltage for each bank, and adjusts the charging process based on results of the comparisons between the measured voltage and the target voltage. | 06-21-2012 |
20120276949 | DYNAMIC THERMAL CONTROL FOR WIRELESS TRANSCEIVERS - Methods and apparatus for dynamic thermal management and control within, e.g., small form-factor wireless devices such as laptop computers or cellular “smartphones”. In one embodiment, a thermal management system monitors the temperature (or other relevant criteria) for one or more components, and implements different operating states within the wireless transceiver (e.g., Wi-Fi™ or WiMAX transceiver) so as to both reduce thermal output and minimize disruption to the wireless link and/or user experience. In another embodiment, a wireless client may communicate with other clients, and/or access points, so as to cooperatively provide more options for thermal management. In addition, methods and apparatus employing “high performance” (e.g., high power output or high data rate) radios within aggressively small industrial designs are also disclosed. | 11-01-2012 |
20120306463 | RESONANT-RECOVERY POWER-REDUCTION TECHNIQUE FOR BOOST CONVERTERS - The disclosed embodiments relate to a power converter system. This power converter system includes an inductor which is coupled between an input that receives an input voltage V | 12-06-2012 |
20130257382 | Managing Cycle and Runtime in Batteries for Portable Electronic Devices - The disclosed embodiments provide a system that manages use of a battery in a portable electronic device. The system includes a monitoring mechanism that monitors one or more battery-usage parameters of the battery during use of the battery with the portable electronic device. The battery-usage parameters may include a battery age, a resting time, a swell rate, a temperature, a cell balance, a voltage, a current, usage data about how the battery has been cycled, and/or user input. The system also includes a management apparatus that adjusts a charge-termination voltage or a discharge-termination voltage of the battery based on the battery-usage parameters to manage a cycle life of the battery, the swell rate, and/or a runtime of the battery. | 10-03-2013 |
20130293210 | COUPLED VOLTAGE CONVERTERS - Embodiments of a power supply are disclosed that include a first voltage converter having a first feedback controller and a first regulated output, and second voltage converter having a second feedback controller and a second regulated output electrically coupled to the first regulated output. The power limit of the first voltage converter is lower than the power limit of the second voltage converter, and a reference voltage for the first feedback controller is higher than the reference voltage for the second feedback controller. | 11-07-2013 |
20130335149 | THE EFFICIENCY OF CLIPPED PULSE GENERATION - The disclosed embodiments provide a resonant oscillator circuit. The resonant oscillator circuit includes a clipping mechanism configured to clip an output voltage of a signal pulse generated by the resonant oscillator circuit to a predefined constant level. The resonant oscillator circuit also includes a feedback path configured to return energy from the clipping mechanism to an input of the resonant oscillator circuit. | 12-19-2013 |
20140082379 | POWERING A DISPLAY CONTROLLER - A method and system are described for powering a display controller in an electronic device. In the described embodiments, the display controller includes a display controller power management circuit directly connected to a battery. | 03-20-2014 |
20140197805 | DIFFUSION-LIMITED ADAPTIVE BATTERY CHARGING - Some embodiments of the present invention provide a system that adaptively charges a battery, wherein the battery is a lithium-ion battery which includes a transport-limiting electrode governed by diffusion, an electrolyte separator and a non-transport-limiting electrode. During operation, the system determines a lithium surface concentration at an interface between the transport-limiting electrode and the electrolyte separator based on a diffusion time for lithium in the transport-limiting electrode. Next, the system calculates a charging current or a charging voltage for the battery based on the determined lithium surface concentration. Finally, the system applies the charging current or the charging voltage to the battery. | 07-17-2014 |
20140247270 | Switching Video Streams for a Display Without a Visible Interruption - The disclosed embodiments provide a system that facilitates driving a display in a computer system. During operation, the system receives an input video stream from a graphics source, wherein the input video stream comprises a sequence of video frames. Next, the system directs the input video stream through a set of two or more memory buffers including a front buffer and a back buffer to produce an output video stream, which is used to drive the display. While directing the input video stream through the set of memory buffers, the system writes a video frame from the input video stream into the back buffer, and concurrently drives the output video stream from a preceding video frame in the front buffer. When the writing of the video frame completes, the system switches buffers so that the back buffer becomes the front buffer, which drives the output video stream, and the front buffer becomes either a spare buffer or the back buffer, which receives a subsequent frame from the input video stream. | 09-04-2014 |