STMicroelectronics

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

Device for the correction of the power factor in forced switching power supplies

Abstract: There is described a device for the correction of the power factor in forced switching power supplies. The device comprises a converter (20) and a control device (100) coupled with the converter (20) in order to obtain from an alternated mains input voltage (Vin) a regulated voltage (Vout) on the output terminal; the converter (20) comprises a power transistor (M) and said control device (100) comprises an error amplifier (3) having in input on the inverting terminal a signal (Vr) proportional to the regulated voltage (Vout) and on the non-inverting terminal a reference voltage (Vref). The signal (Vr) proportional to the regulated voltage is produced by a first resistance (R1) and a second resistance (R2) coupled in series to which is applied said regulated voltage (Vout); a terminal of the second resistance (R2) is connected with the inverting terminal of the error amplifier (3). The device for the correction of the power factor comprises first means (D50) positioned between the first resistance (RI) and the inverting terminal of the error amplifier (3) and second means (50) suitable for detecting the electrical connection of the first means (D50) with the output terminal of said device for the correction of the power factor and suitable for detecting an output signal (Vr2) of the second resistance (R2). The second means (50) are suitable for supplying a malfunction signal (Fault) of the device for the correction of the power factor when the second means (50) detect electric disconnection of the first means (D50) from said output terminal (Out) or when the output signal (Vr2) of the second resistance (R2) tends to zero.

BGA/LGA with built in heat slug/spreader

Abstract: A ball or land grid array plastic substrate portion is formed with a hole therethrough in the region on which the integrated circuit die is to be formed, with a copper heat slug inserted within the opening having a bottom surface substantially aligned with the bottom surface of the plastic portion to allow molding tooling for conventional ball or land grid array packages to be employed. The integrated circuit die is mounted on the heat slug, which has a solderable bottom surface and is directly soldered to the PCB. An additional copper heat spreader region is formed on an upper surface of the plastic portion.

On the Origin of Low-Resistance State Retention Failure in HfO 2 -Based RRAM and Impact of Doping/Alloying

Abstract: We study in detail the impact of alloying HfO2 with Al (Hf1– x Al2 x O2+ x ) on the oxide-based resistive random access memory (RRAM) (OxRRAM) thermal stability through material characterization, electrical measurements, and atomistic simulation. Indeed, migration of oxygen atoms inside the dielectric is at the heart of OxRRAM operations. Hence, we performed comprehensive diffusion barrier calculations in HfO2, Hf1– x Al2 x O2+ x , and Hf1– x Ti x O2 relative to the oxygen vacancy ( $V_{o}$ ) movement involved in low-resistance state ( $R_{\mathrm{\scriptscriptstyle ON}}$ ) thermal stability. Calculations are performed at the best level using ab initio techniques. This paper provides an insight on the improved $R_{\mathrm{\scriptscriptstyle ON}}$ stability of our Hf1– x Al2 x O2+ x -based RRAM devices and predicts the degraded retention of Hf1– x Ti x O2-based RRAM measured in the literature. Our theoretical calculations link the origin of $R_{\mathrm{\scriptscriptstyle ON}}$ retention failure to the lateral diffusion of oxygen vacancies at the constriction/tip of the conductive filament in HfO2-based RRAM.

A 0.92-THz SiGe Power Radiator Based on a Nonlinear Theory for Harmonic Generation

Abstract: We propose a nonlinear device model and a systematic methodology to generate maximum power at any desired harmonic. The proposed power optimization technique is based on the Volterra-Wiener theory of nonlinear systems. By manipulating the device nonlinearity and optimizing the embedding network, optimum conditions for harmonic power generation are provided. Using this theory, a 920–944-GHz frequency quadrupler is designed in a 130-nm SiGe:C process. The circuit achieves the peak output power of −17.3 and −10 dBm of effective isotropic radiated power and consumes 5.7 mW of dc power. To the best of our knowledge, this circuit demonstrates the highest generated power among Si/SiGe-based sources at this frequency range.