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.

Biometric sensor apparatus and method

Abstract: A biometric sensor apparatus uses an infra red light source and a CMOS image sensor. A platen receives a body part and the image sensor receives light transmitted through the body part. A processor determines from the detected through-transmitted light whether the body part is live or is a spoof body part. This determination is based upon a detected variation of the opacity of the body part due to blood flow through the body part. Digital processing of the collected image signal data is performed, such as by smoothing. The sensor may further function as a pattern (such as a fingerprint) sensor for detecting surface patterns on the presented body part and identifying an individual from those sensed patterns.

Fuzzy logic applied to motor control

Abstract: Today, home appliance applications require more and more features such as motor speed adaptations to multipurpose accessories, user friendly interfaces, and security features. Such new requirements can be achieved through a low-end microcontroller-based electronic control using the fuzzy logic approach. Nowadays, most of fuzzy logic-based controls are only limited to a complicated ranking management of user interfaces, sensors, and actuators, corresponding to a slow software speed operation. This paper proposes a totally different use of fuzzy logic. In this case, fuzzy logic is implemented in a standard microcontroller to regulate the speed of a universal motor by a real time adjustment (every 30 millisecond) of the motor current. This microcontroller directly tunes the motor current by means of a chopper converter. Starting from a basic food-processor application, the paper practically shows how a fuzzy logic approach can be applied to build a closed speed regulation loop from a very low cost tacho-generator. Practical guidelines are successively given from the initial concept analysis phase, up to the final generation of the executable code to be loaded in the microcontroller. The paper also gives the practical procedure to define the input parameters and to build fuzzy logic rules when using the fuzzy logic development tool. Finally, the major benefits of this paper lie in an original approach where fuzzy logic is applied to fast "real-time" regulation loop without requiring any specific expertise in conventional methods of regulation. Benefits are discussed and concrete results are given.

Lab-on-Chip for Exosomes and Microvesicles Detection and Characterization

Abstract: Interest in extracellular vesicles and in particular microvesicles and exosomes, which are constitutively produced by cells, is on the rise for their huge potential as biomarkers in a high number of disorders and pathologies as they are considered as carriers of information among cells, as well as being responsible for the spreading of diseases. Current methods of analysis of microvesicles and exosomes do not fulfill the requirements for their in-depth investigation and the complete exploitation of their diagnostic and prognostic value. Lab-on-chip methods have the potential and capabilities to bridge this gap and the technology is mature enough to provide all the necessary steps for a completely automated analysis of extracellular vesicles in body fluids. In this paper we provide an overview of the biological role of extracellular vesicles, standard biochemical methods of analysis and their limits, and a survey of lab-on-chip methods that are able to meet the needs of a deeper exploitation of these biological entities to drive their use in common clinical practice.

LED driving device with variable light intensity

Abstract: In a device for driving LEDs with variable light intensity, a supply stage has a first operating mode, in which a controlled supply current is generated, and a second operating mode, in which a controlled supply voltage is generated. A LED is connected to the supply stage, receives the controlled supply current or voltage, and has a turning-on threshold voltage higher than the controlled supply voltage. A current sensor generates a current-feedback signal that is correlated to the current flowing in the LED and is supplied to the supply stage in the first operating mode. An intensity-control stage generates a mode-control signal that is sent to the supply stage and controls sequential switching between the first and the second operating modes of the supply stage.

A CMOS low-distortion fully differential power amplifier with double nested Miller compensation

Abstract: A four-stage fully differential power amplifier using a double-nested Miller compensated structure is presented. The multiple-loop configuration used results in a lower harmonic distortion, at least in the audio band, compared to conventional three-stage amplifiers with nested Miller compensation. Design criteria and stability conditions for good stability of amplifiers using a multiple- (greater than two) loop topology are presented. The amplifier operates with a single power supply which has a minimum value of 3 V. With a 5-V supply, power dissipation is 10 mW and total harmonic distortion (THD) is -83 dB for a -V/sub p-p/ differential output signal at 10 kHz and a load of 50 Omega . With an 8 Omega load and for a 10-kHz, 4-V/sub p-p/ output signal, THD is -68 dB. The chip area is 0.625 mm/sup 2/ in a 1.5- mu m single-poly, double-metal, n-well CMOS technology. >