1,721,010 research outputs found
Adolescencia y juventud. Entre los estereotipos y la construcción de la subjetividad
Full text linkFil: Butti, Federico, . Universidad Nacional de Villa María; Argentina
A Chopper Instrumentation Amplifier with Input Resistance Boosting by Means of Synchronous Dynamic Element Matching
Full text linkIn this work, we propose a method to increase the parasitic input resistance caused by application of chopper modulation to indirect current feedback instrumentation amplifiers. The result is obtained by applying dynamic element matching to the input and feedback ports at the same frequency as chopper modulation. The proposed approach requires effective offset ripple rejection and equalization of the input and feedback common mode voltages. An in-Amp architecture that meets both requirements and embodies the proposed input resistance boosting method is described. Experimental verification is provided by means of a prototype designed and fabricated using the 0.32mu text m CMOS devices of the STMicroelectronics BCD6s process. The amplifier operates with a 3.3 V supply voltage and a total current absorption of 170 mu text A. An input impedance in excess of 1 ext GOmega has been measured at a chopper frequency of 20 kHz. The input referred voltage noise density is 18 nV/sqrt(Hz) with a flicker corner of 0.2 Hz and 200 Hz bandwidth
Area optimization of very low-frequency Gm-C filters
No full textFully integrated low frequency filters are critical cells that should be carefully designed in order to avoid excessive area occupation. In this work we propose an automatic procedure capable of optimizing the design of Gm-C integrators, constituting the basis of a wide class of Gm-C filters. The optimization target is minimizing the cell area with constraints on input range and low frequency noise. The procedure is exploited to show the effect of various design constraints on important filter parameters. Verification with the result of electrical simulations is included
Nuevos contextos laborales y producción de subjetividad
No full textLa crisis del 2001 y los cambios culturales, sociales, políticos y económicos del capitalismo tardío impactaron de modo decidido tanto en la configuración de las condiciones de trabajo como en los procesos de subjetivación laboral. Desde la perspectiva teórica esto ha propiciado un reposicionamiento de las teorías que analizan la relación estructura-agente, reivindicando el retorno del sujeto, los procesos de individuación/individualización y la producción de subjetividades desde un enfoque microsociológico.Fil: Pérez Rubio, Ana María. Universidad Nacional del Nordeste. Facultad de Humanidades; Argentina.Fil: Pérez Rubio, Ana María. Universidad Nacional del Nordeste. Centro de Estudios Sociales; Argentina.Fil: Pérez Rubio, Ana María. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones Geohistóricas; Argentina.Fil: Butti, Federico. Universidad Nacional del Nordeste. Centro de Estudios Sociales; Argentina
A low power CMOS capacitance to pulse duration converter based on a dual clock approach
No full textAn interface for integrated capacitive sensors
producing a PWM signal is presented. The circuit is based on a
recently proposed architecture, which is here improved by the
introduction of a double clock strategy allowing jitter reduction.
The non idealities of the circuit are investigated in order to
obtain design criteria to reduce the jitter and the temperature
dependence. The approach is validated with electrical simulations
performed on a prototype designed with devices from the
0.32 μm CMOS subset of the STMicroelectronics BCD6s process
A compact instrumentation amplifier for MEMS sensor interfacing
No full textA compact CMOS instrumentation amplifier, based on the chopper modulation approach, is proposed as a possible readout channel for integrated thermoelectric sensors. The circuit merges amplification and filtering functions. This property allows effective rejection of the modulated offset ripple. An original switching strategy involving swapping of the input and feedback port is used to improve the gain precision. The effectiveness of the technique is illustrated by means of electrical simulations performed on a prototype designed with the STMicroelectronics BCD6s process
A compact instrumentation amplifier for MEMS thermal sensor interfacing
No full textA compact CMOS instrumentation amplifier,
based on a properly modified second order Gm–C low pass
filter (LPF), is proposed as a possible readout channel for
integrated thermal sensors. Low noise and low offset
characteristics are obtained by applying chopper modulation
to the input transconductor. The high input thermal
noise density, typical of low frequency Gm–C filters, has
been significantly reduced by adopting a two-stage topology
for the first transconductor. Using this approach, an
input noise density adequate for thermal sensor interfacing
was obtained with no need of off-chip capacitors. The
intrinsic filtering property of the amplifier effectively
rejects the modulated offset ripple, allowing direct connection
of the amplifier output to a low sampling rate AD
converter. An original switching strategy involving swapping
of the input and feedback ports is used to improve the
gain precision. The effectiveness of the technique is proven
by means of analytical arguments and electrical simulations
performed on a prototype, designed with the STMicroelectronics
BCD6s process
A single chip, offset compensated multi-channel flow sensor with integrated readout interface
No full textAn integrated sensor capable of detecting multiple gas flows is presented. The sensor incorporates several recently introduced innovations, allowing virtually drift free offset compensation and reduction of the dependence on pressure. Furthermore, an inexpensive packaging method is used to convey distinct gas flows to separate areas of the relatively small chip. Results of tests performed in nitrogen flow are presente
A Low-Power Interface for Capacitive Sensors With PWM Output and Intrinsic Low Pass Characteristic
Full text linkA compact, low power interface for capacitive sensors, is described. The output signal is a pulse width modulated (PWM) signal, where the pulse duration is linearly proportional to the sensor differential capacitance. The original conversion approach consists in stimulating the sensor capacitor with a triangular-like voltage waveform in order to obtain a square-like current waveform, which is subsequently demodulated and integrated over a clock period. The charge obtained in this way is then converted into the output pulse duration by an approach that includes an intrinsic tunable low pass function. The main non idealities are thoroughly investigated in order to provide useful design indications and evaluate the actual potentialities of the proposed circuit. The theoretical predictions are compared with experimental results obtained with a prototype, designed and fabricated using 0.32 mu M CMOS devices from the BCD6s process of STMicroelectroncs. The prototype occupies a total area of 1025 x 515 mm(2) and is marked by a power consuption of 84 mu W. The input capacitance range is 0-256 fF, with a resolution of 0.8 fF and a temperature sensitivity of 300 ppm/degrees C
A chopper modulated low noise instrumentation amplifier for MEMS thermal sensors interfacing
No full textA CMOS instrumentation amplifier for interfacing integrated thermal sensors is proposed. It is based on a Gm-C 2nd order low pass filter, and exploits chopper modulation to improve its performances in terms of offset and low frequency noise. An input noise level of 10 nV/sqrt(Hz) and a current consumption of a few hundred of μA have been obtained by means of a careful design. Moreover, an original technique of input and feedback port swapping improves the amplifier gain precision. A prototype has been designed with the BCD6s STMicroelectronics process, and its functionality has been demonstrated by means of electrical simulations
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