STMicroelectronics

About: STMicroelectronics is a company organization based out in Geneva, Switzerland. It is known for research contribution in the topics: Signal & Transistor. The organization has 17172 authors who have published 29543 publications receiving 300766 citations. The organization is also known as: SGS-Thomson & STM.

Two independent components modeling for Negative Bias Temperature Instability

Abstract: Based on vast experimental dataset obtained from different technologies (pure or nitrided SiO 2 and HK), we suggest that Negative Bias Temperature Instability is made of two independent components, presenting different voltage and temperature acceleration factors as well as process dependences. The recoverable part, subject to fast transient effects, is shown to obey field-assisted LRME hole trapping/detrapping processes. The permanent part is shown to be made of an equal number of interface traps and positive fixed charges, as resulting from hydrogen transfer to oxygen bridge. This hydrogen transfer was shown for the firs time to be reversible allowing in-depth analysis of the microscopic mechanisms at play.

Low-voltage double-sampled /spl Sigma//spl Delta/ converters

Abstract: An obvious way of achieving higher signal-to-noise ratio in oversampled data converters is by increasing the effective sampling rate. If all other components are kept constant, this translates into integrators with larger bandwidth that in turn results in higher overall power consumption. This work introduces the fully floating switched-capacitor configuration as a simple and robust technique to effectively double the sampling rate of oversampled data converters without compromising any aspect of the performance and yet maintaining the power levels of the conventional approach. The use of internal decimation in the switched-capacitor ladder structure of the digital-to-analog converter further helps in achieving the power budget goals. These converters have been implemented with circuitry capable of operating at a minimum supply voltage of 1.8 V under worst case process and temperature conditions and using clock bootstrapping for the transfer gates. The bootstrapping circuit described here uses a single internal capacitor and has functionality that limits the maximum clock voltage to safe levels under a wide range of supply voltages. The prototype was fabricated in a 0.5-/spl mu/m CMOS double-poly technology. The analog-to-digital converter occupies a die area of 0.11 mm/sup 2/ dissipating 550 /spl mu/W while the digital-to-analog converter occupies 0.28 mm/sup 2/ dissipating 600 /spl mu/W.

Autotuning of Digitally Controlled DC–DC Converters Based on Relay Feedback

Abstract: This paper proposes a simple autotuning technique for digitally controlled dc-dc converters. The proposed approach is based on the relay feedback method and introduces perturbations on the output voltage during converter soft-start. By using an iterative procedure, the tuning of proportional-integral-derivative parameters is obtained directly by including the controller in the relay feedback and by adjusting the controller parameters based on the specified phase margin and control loop bandwidth. A nice property of the proposed solution is that output voltage perturbations are introduced while maintaining the relay feedback control on the output voltage. The proposed algorithm is simple, requires small tuning times, and it is compliant with the cost/complexity constraints of integrated digital integrated circuits. Simulation and experimental results of a synchronous buck converter and of a dc-dc boost converter confirm the effectiveness of the proposed solution

Single-chip CMOS pulse generator for UWB systems

Abstract: This paper presents a single-chip pulse generator developed for Ultra Wide Band (UWB) wireless communication systems based on impulse radio technology. The chip has been integrated in a CMOS 130-nm technology with a single supply voltage of 1.2 V. The basic concept is to combine different delayed edges in order to form a very short duration "logical" pulse, and then filter it, so as to obtain an UWB pulse. It is possible to vary the output pulse shape, and thus the corresponding spectrum, just by acting on the delayed edge combination. Furthermore, the pulse generator supports both position modulation (2-PPM) and polarity modulation (BPSK modulation) in order to convey data through the air. Its power consumption remains less than 10 mW for a raw data rate of up to 160 Mb/s. Spectral and temporal measurements of the single-chip pulse generator are presented with an illustration of the modulation effects on the power spectral density (PSD)

Solid state event recorder

Abstract: A solid state event recorder having particular application to railroad locomotives has a plurality of interface modules to allow the collection of desired data over a period of time. Radio downloading of the data provided by a telemetry transmitter to wayside receivers is the primary way of downloading data. Alternative data downloading are provided by a removable memory module, a portable wireless data extractor and a laptop computer. The removable memory module is provided with its own backup battery power supply but normally derives its power from an inductive coupling to the solid state recorder. Data is read into the removable memory module from the solid state recorder via an inductive coupling, and data is read out of the removable memory module to the telemetry transmitter via another inductive coupling. Both the portable wireless data extractor and the laptop computer are used for maintenance purposes. The solid state recorder can be configured in a variety of ways and connected together as master and slave. For example, one recorder, acting as a master and functioning as the primary of operational recorder, can be connected to a second recorder, acting as a slave time synchronized with the first recorder. This second recorder can serve as a maintenance recorder for collecting long term data and trouble shooting a particular locomotive.