Abstract: An electronic device may include a display. The display may be formed by an array of light-emitting diodes mounted to the surface of a substrate. The substrate may be a silicon substrate. Circuitry may be located in spaces between the light-emitting diodes. Circuitry may also be located on the rear surface of the silicon substrate and may be coupled to the array of light-emitting diodes using through-silicon vias. The circuitry may include integrated circuits and other components that are attached to the substrate and may include transistors and other circuitry formed within the silicon substrate. Touch sensor electrodes, light sensors, and other components may be located in the spaces between the light-emitting diodes. The substrate may be formed from a transparent material that allows image light to reach a lens and image sensor mounted below the substrate.

Abstract: An electronic device may include a display. The display may be formed by an array of light-emitting diodes mounted to the surface of a substrate. The substrate may be a silicon substrate. Circuitry may be located in spaces between the light-emitting diodes. Circuitry may also be located on the rear surface of the silicon substrate and may be coupled to the array of light-emitting diodes using through-silicon vias. The circuitry may include integrated circuits and other components that are attached to the substrate and may include transistors and other circuitry formed within the silicon substrate. Touch sensor electrodes, light sensors, and other components may be located in the spaces between the light-emitting diodes. The substrate may be formed from a transparent material that allows image light to reach a lens and image sensor mounted below the substrate.

Abstract: Individual health related events (e.g., handwashing events) can be detected based on multiple sensors including motion and audio sensors. Detecting a qualifying handwashing event can include detecting a qualifying scrubbing event based on motion data (e.g., accelerometer data) and a qualifying rinsing event based on audio data. In some examples, power consumption can be reduced by implementing one or more power saving mitigations.

Abstract: Individual health related events (e.g., handwashing events) can be detected based on multiple sensors including motion and audio sensors. Detecting a qualifying handwashing event can include detecting a qualifying scrubbing event based on motion data (e.g., accelerometer data) and a qualifying rinsing event based on audio data. In some examples, power consumption can be reduced by implementing one or more power saving mitigations.

Abstract: An interpolation circuit included in a computer system may receive an operand that includes a plurality of bits occupying respective ones of a plurality of ordered bit positions, and generate multiple conditionally-negated values of respective portions of the operand starting at corresponding bit positions. The interpolation circuit may combine the operand and the plurality of conditionally-negated values to generate an approximation of a result of an arithmetic operation performed on the operand.

Abstract: Individual health related events (e.g., handwashing events) can be detected based on multiple sensors including motion and audio sensors. Detecting a qualifying handwashing event can include detecting a qualifying scrubbing event based on motion data (e.g., accelerometer data) and a qualifying rinsing event based on audio data. In some examples, power consumption can be reduced by implementing one or more power saving mitigations.

Abstract: An interpolation circuit included in a computer system may receive an operand that includes a plurality of bits occupying respective ones of a plurality of ordered bit positions, and generate multiple conditionally-negated values of respective portions of the operand starting at corresponding bit positions. The interpolation circuit may combine the operand and the plurality of conditionally-negated values to generate an approximation of a result of an arithmetic operation performed on the operand.

Abstract: Individual health related events (e.g., handwashing events) can be detected based on multiple sensors including motion and audio sensors. Detecting a qualifying handwashing event can include detecting a qualifying scrubbing event based on motion data (e.g., accelerometer data) and a qualifying rinsing event based on audio data. In some examples, power consumption can be reduced by implementing one or more power saving mitigations.

Abstract: An electronic device may include a display. The display may be formed by an array of light-emitting diodes mounted to the surface of a substrate. The substrate may be a silicon substrate. Circuitry may be located in spaces between the light-emitting diodes. Circuitry may also be located on the rear surface of the silicon substrate and may be coupled to the array of light-emitting diodes using through-silicon vias. The circuitry may include integrated circuits and other components that are attached to the substrate and may include transistors and other circuitry formed within the silicon substrate. Touch sensor electrodes, light sensors, and other components may be located in the spaces between the light-emitting diodes. The substrate may be formed from a transparent material that allows image light to reach a lens and image sensor mounted below the substrate.

Abstract: An electronic device may include a display. The display may be formed by an array of light-emitting diodes mounted to the surface of a substrate. The substrate may be a silicon substrate. Circuitry may be located in spaces between the light-emitting diodes. Circuitry may also be located on the rear surface of the silicon substrate and may be coupled to the array of light-emitting diodes using through-silicon vias. The circuitry may include integrated circuits and other components that are attached to the substrate and may include transistors and other circuitry formed within the silicon substrate. Touch sensor electrodes, light sensors, and other components may be located in the spaces between the light-emitting diodes. The substrate may be formed from a transparent material that allows image light to reach a lens and image sensor mounted below the substrate.

Abstract: A comb light source and spectrometer is disclosed. The comb light source and spectrometer can include a plurality of light emitters, where each light emitter can be configured to emit light included in a plurality of wavelength bands. Each wavelength band can be separated from an adjacent wavelength band by a noise band. Due to the separated wavelength bands for a light emitter, any signal received outside of the one or more wavelength bands can originate from noise (e.g., drift, ambient light, electrical noise), thereby enhancing signal analysis and noise rejection. In some examples, the comb light emitters can be activated sequentially such that a plurality of wavelengths across a spectrum can be measured. In some examples, the resolution and the number of spectral lines in the comb light source can be tuned by changing the properties of the quantum dots and/or increasing the number of comb light emitters.

Abstract: 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.

Abstract: 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.

Abstract: The disclosed embodiments provide a system that manages use of a battery in a portable electronic device. During operation, the system provides a charging circuit for converting an input voltage from a power source into a set of output voltages for charging the battery and powering a low-voltage subsystem and a high-voltage subsystem in the portable electronic device. Upon detecting discharging of the battery in a low-voltage state, the system uses the charging circuit to directly power the low-voltage subsystem from a battery voltage of the battery and up-convert the battery voltage to power the high-voltage subsystem.

Abstract: The disclosed embodiments provide a system that operates a power supply. During operation, the system obtains power states of two or more loads coupled to two or more power converters in the power supply. Next, the system generates one or more control signals for a set of switching mechanisms to configure a coupling of the two or more loads to the two or more power converters through the switching mechanisms based on the power states.

Abstract: The disclosed embodiments provide a system that operates a power supply. During operation, the system disposes a first switching mechanism between a first output of a first power converter and two or more loads. Next, the system obtains two or more error signals for the two or more loads, wherein each error signal from the two or more error signals represents a difference between a load voltage of a load from the two or more loads and a first reference voltage for the load from a first set of reference voltages for driving the two or more loads using the first power converter. The system then uses the first switching mechanism to couple the load with a largest error signal from the two or more error signals to the first output.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: The disclosed embodiments provide a circuit for driving a capacitive load. The circuit includes a first inductor with an input terminal and a load terminal, wherein the load terminal is coupled to the capacitive load. The circuit also includes four or more switching devices. The switching devices may hold a voltage on the load terminal at zero volts. Next, the switching devices may charge the capacitive load through the first inductor until the voltage on the load terminal reaches a first input voltage supplied by a voltage source. The switching devices may then hold the voltage on the load terminal at the first input voltage. Finally, the switching devices may discharge the capacitive load through the first inductor until the voltage on the load terminal reaches zero volts.