Freescale Semiconductor

About: Freescale Semiconductor is a based out in . It is known for research contribution in the topics: Layer (electronics) & Signal. The organization has 7673 authors who have published 10781 publications receiving 149123 citations. The organization is also known as: Freescale Semiconductor, Inc..

Piezoelectric micro-power generation interface circuits

Abstract: New power conversion circuits to interface to a piezoelectric micro-power generator have been fabricated and tested. Circuit designs and measurement results are presented for a half-wave synchronous rectifier with voltage doubler, a full-wave synchronous rectifier and a passive full-wave rectifier circuit connected to the piezoelectric micro-power generator. The measured power efficiency of the synchronous rectifier and voltage doubler circuit fabricated in a 0.35-/spl mu/m CMOS process is 88% and the output power exceeds 2.5 /spl mu/W with a 100-k/spl Omega/, 100-nF load. The two full-wave rectifiers (passive and synchronous) were fabricated in a 0.25-/spl mu/m CMOS process. The measured peak power efficiency for the passive full-wave rectifier circuit is 66% with a 220-k/spl Omega/ load and supplies a peak output power of 16 /spl mu/W with a 68-k/spl Omega/ load. Although the active full-wave synchronous rectifier requires quiescent current for operation, it has a higher peak efficiency of 86% with an 82-k/spl Omega/ load, and also exhibits a higher peak power of 22 /spl mu/W with a 68-k/spl Omega/ load which is 37% higher than the passive full-wave rectifier.

Overmolded semiconductor device having solder ball and edge lead connective structure

Abstract: A low cost manufacturing method is used to fabricate a small multiple chip semiconductor device (10). In one embodiment, a first pattern of conductive traces (14) is formed on one surface of a substrate (12), and a second pattern of traces (16) is formed on a second surface of the substrate (12). A first semiconductor die (20) is interconnected to the first traces (14), and a package body (24) is formed around the first die and a portion of the traces. A second semiconductor die (26) is interconnected to the second traces (16) on the second surface. A second package body (28) is formed around the second die and a portion of the traces (16). Solder balls (32) are coupled to exposed portions of the second traces (16) around the perimeter of the package body (28) to establish external power and ground connections to each die. Edge leads (36) are externally soldered to the traces (14 & 16) around the periphery of the substrate (12) to establish remaining electrical connections.

Multimillimetre-large superlattices of air-stable iron–cobalt nanoparticles

Abstract: Self-organization of nanoparticles into two- and three-dimensional superlattices on a large scale is required for their implementation into nano- or microelectronic devices1,2. This is achieved, generally after a size-selection process3,4, through spontaneous self-organization on a surface5,6,7,8,9,10,11, layer-by-layer deposition12 or the three-layer technique of oversaturation3,14, but these techniques consider superlattices of limited size. An alternative method developed in our group involves the direct formation in solution of crystalline superlattices, for example of tin nanospheres, iron nanocubes or cobalt nanorods, but these are also of limited size15,16,17. Here, we report the first direct preparation in solution of multimillimetre-sized three-dimensional compact superlattices of nanoparticles. The 15-nm monodisperse FeCo particles adopt an unusual short-range atomic order that transforms into body-centred-cubic on annealing at 500 ∘C. The latter process produces an air-stable material with magnetic properties suitable for radiofrequency applications.

A Novel ZVZCS Full-Bridge DC/DC Converter Used for Electric Vehicles

Abstract: This paper presents a novel ZVZCS full-bridge DC/DC converter, which is able to process and deliver power efficiently over very wide load variations. The proposed DC/DC converter is part of a plug-in AC/DC converter used to charge the traction battery (high voltage battery) in an electric vehicle. The key challenge in this application is operation of the full-bridge converter from absolutely no-load to full-load conditions. In order to confirm reliable operation of the full-bridge converter under such wide load variations, the converter should not only operate with soft-switching from full load to no-load condition with satisfactory efficiency for the full range of operation, but also the voltage across the output diode bridge needs to be clamped to avoid any adverse voltage overshoots arising during turn-OFF of the output diodes as commonly found in regular full bridge converters. In order to achieve such stringent requirements and high reliability, the converter employs a symmetric passive near lossless auxiliary circuit to provide the reactive current for the full-bridge semiconductor switches, which guarantees zero voltage switching at turn-ON times for all load conditions. Moreover the proposed topology is based on a current driven rectifier in order to clamp the voltage of the output diode bridge and also satisfy ZVZCS operation of the converter resulting in superior efficiency for all load conditions. In this paper operation of the converter is presented in detail followed by analytical design procedure. Experimental results provided from a 3KW prototype validate the feasibility and superior performance of the proposed converter.

Prognostic and Warning System for Power-Electronic Modules in Electric, Hybrid Electric, and Fuel-Cell Vehicles

Abstract: Reliability of power-electronic modules is of paramount importance for the commercial success of various types of electric vehicles. In this paper, we study the technical feasibility of detecting and utilizing early symptoms and warning signs of power-module degradation due to thermomechanical stress and fatigue and develop a prognostic system that can monitor the state of health of the power modules in electric, hybrid, and fuel-cell vehicles. A special degradation trace on the VCEsat of the insulated-gate bipolar-transistor modules was observed by a power-cycling accelerated test, which was not reported in literatures. A prognostic system based on utilizing the aforementioned trace is then developed. The system consists of the hardware architecture and current adaptive-algorithm-based software architecture. In addition, this prognostic system hardly increases the hardware cost on existing vehicle-driver system. An extensive simulation based on MATLAB/Simulink verifies the developed prognostic system.