A converter circuit and related technique for providing high power density power conversion includes a reconfigurable switched capacitor transformation stage coupled to a magnetic converter (or regulation) stage. The circuits and techniques achieve high performance over a wide input voltage range or a wide output voltage range. The converter can be used, for example, to power logic devices in portable battery operated devices.

Power Converter With Capacitive Energy Transfer And Fast Dynamic Response

Circuits and methods for achieving high linearity, high efficiency power amplifiers, including digital predistortion (DPD) and pulse cancellation in switched-state RF power amplifier systems are described.

Linearization Circuits And Methods For Multilevel Power Amplifier Systems

A radio frequency (RF) power amplifier system or transmitter includes one or more power amplifiers and a controller that is configured to adjust amplitudes and phases of RF input signals of the one or more power amplifiers and supply voltages applied to the one or more power amplifiers. In embodiments where multiple power amplifiers are used, a combiner may be provided to combine outputs of the power amplifiers. In at least one implementation, amplitude adjustment of the RF input signals of the one or more power amplifiers may be used to provide transmit power control and/or power backoff.

RF amplifier architecture and related techniques

Multistage matching networks are often utilized to provide voltage or current gains in resonant conversion applications, such as large conversion ratio power converters and wireless power transfer. In the conventional approach, each stage of a multistage matching network is designed to have a purely resistive input impedance and assumed to be loaded by a purely resistive load. This paper introduces an improved design optimization approach for multistage matching networks comprising L-section stages. The proposed design optimization approach explores the possibility of improvement in efficiency of the network by allowing the L-section stages to have complex input and load impedances. A new analytical framework is developed to determine the effective transformation ratio and efficiency of each stage for the case when input and load impedances may be complex. The method of Lagrange multipliers is used to determine the gain and impedance characteristics of each stage in the matching network that maximize overall efficiency. Compared with the conventional design approach for matching networks, the proposed approach achieves higher efficiency, resulting in loss reduction of up to 35% for a three-stage L-section matching network. The theoretical predictions are validated experimentally using a three-stage matching network designed for 1 MHz and 100 W operation.

Improved Design Optimization for High-Efficiency Matching Networks

An integrated power supply and modulator system includes integrated power supply and modulator system includes three subsystems: a switched-capacitor voltage balancer stage; a magnetic regulation stage; and at least one output switching stage In one embodiment, the integrated power supply and modulator system further includes startup circuitry, feedback/feedforward circuitry and control circuitry

Integrated power supply and modulator for radio frequency power amplifiers

A voltage-step down rectifier topology suitable for integration on a die of an integrated circuit is described. In one embodiment, a switched capacitor rectifier is provided having an architecture such that an input voltage swing of the switched-capacitor rectifier is a factor N times an output voltage where N depends upon the number of stages such that the switched-capacitor rectifier can provide a π/(2N) step-down voltage conversion ratio between an input fundamental ac peak voltage to the output dc voltage. In one embodiment, the rectifier is used in dc-dc conversion. In one embodiment, the rectifier is used in ac power delivery to low-voltage electronics.

Apparatus for multi-level switched-capacitor rectification and DC-DC conversion

Certain aspects relate to systems and techniques for color temperature analysis and matching. For example, three or more camera flash LEDs of different output colors can be used to match any of a range of ambient color temperatures in a non-linear space on the black body curve. The scene color temperature can be analyzed in a preliminary image by determining actual sensor R/G and B/G ratios, enabling more accurate matching of foreground flash lighting to background lighting by the reference illuminant for subsequent white balance processing. The current provided to, and therefore brightness emitted from, each LED can be individually controlled based on the determined sensor response to provide a dynamic and adaptive mix of the output colors of the LEDs.

Multi-led camera flash for color temperature matching

Multi-step, switched-capacitor rectifier and dc-dc converter circuits and related techniques

Systems and methods for illuminating a subject for image capture are described herein. A processor may determine an ambient color temperature of a subject. The processor may further determine a color temperature for outputting light from a display facing a first direction based on a light output characteristic for a dedicated illumination element facing the first direction, the determined ambient color temperature, and a desired color temperature of the subject. The processor may further illuminate the subject using both the dedicated illumination element and the display. The display may output light based on the determined color temperature for outputting light from the display. The processor may further capture, using an image sensor facing the first direction, an image of the subject during the subject being illuminated using both the dedicated illumination element and the display.

Dedicated illumination element and display based flash illumination for image capture

Future computation systems pose a major challenge in energy delivery that is difficult to meet with existing devices and design strategies. To reduce interconnect bottlenecks and enable more flexible computation and energy utilization, it is desired to deliver power across the interconnect to the chip at high voltage and low current with on- or over-die transformation to low voltage and high current. This paper presents an integrated converter architecture with ac voltage transformation to provide very-high-frequency, low-voltage integrated power delivery.

Nathaniel Jay T. Salazar

Papers

Apparatus for multi-level switched-capacitor rectification and DC-DC conversion

Multi-led camera flash for color temperature matching

Multi-step, switched-capacitor rectifier and dc-dc converter circuits and related techniques

Dedicated illumination element and display based flash illumination for image capture

Integrated low-voltage converter architecture with ac power delivery