Person:
Cruz Blas, Carlos Aristóteles de la

Last Name

Cruz Blas

First Name

Carlos Aristóteles de la

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Ingeniería Eléctrica, Electrónica y de Comunicación

ORCID

0000-0002-4136-5079

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3527

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Now showing 1 - 10 of 23

Open Access
Low-power ultrasonic front-end for cargo container monitoring
(IEEE, 2019) Algueta-Miguel, Jose M.; García Oya, José Ramón; López Martín, Antonio; Cruz Blas, Carlos Aristóteles de la; Muñoz Chavero, Fernando; Hidalgo Fort, Eduardo; Institute of Smart Cities - ISC
A low-power ultrasonic communication system conceived for cargo container monitoring is presented. Two piezoelectric transducers operating at 40 kHz are used for generating and acquiring an ultrasonic signal through the metallic wall, thus establishing a non-invasive inside-outside communication that preserves the container integrity. Both transducers are fixed by means of a novel magnetic case designed for optimizing data transmission. The acoustic and electrical characteristics of the ultrasonic channel are analyzed. An experimental measurement setup based on FPGA has been implemented for comparing some basic modulation and detection schemes in terms of Bit Error Rate (BER), also considering their robustness against undesired mechanical and electromagnetic perturbations. On this basis, a compact digital DBPSK modulator using a square carrier signal is proposed. Frequency and amplitude tracking algorithms are designed for optimizing the quality and robustness of the data transmission. Finally, a low-power low-rate (up to few kbps) architecture based on the previous elements is presented. All the proposed contributions are experimentally validated.
Open Access
0.6-V CMOS bulk-driven instrumentation amplifier for IoMT bioimpedance analysis
(Wiley, 2024) Carrillo, Juan M.; Ocampo-Hidalgo, Juan J.; Corbacho, Israel; Cruz Blas, Carlos Aristóteles de la; Domínguez, Miguel Á.; Ingeniería Eléctrica, Electrónica y de Comunicación; Ingeniaritza Elektrikoa, Elektronikoa eta Telekomunikazio Ingeniaritza; Institute of Smart Cities - ISC
An instrumentation amplifier (IA), aimed at wideband bioimpedance analysisin the low-voltage low-power scenario of internet of medical things (IoMT), ispresented. The operation principle is based on the indirect current feedbacktechnique, where an input and a feedback transconductor determine thevoltage gain of the preamplifier. The required transconductors consist of twobulk-driven flipped-voltage-follower cells and an active pseudo-resistor, thusleading to a linear and compact implementation. The circuit has been designedand fabricated in 180 nm CMOS technology to operate with a 0.6-V supply.Experimental results obtained from measurements on eight samples of thesilicon prototype show that when the IA is programmed to have a nominalvoltage gain of 11 V/V, the bandwidth is 316.2 kHz, the CMRR exceeds63 dB, and the maximum output voltage that can be processed with a THDbelow –40 dB is 555 mVpp.
Open Access
Single-stage class-AB non-linear current mirror OTA
(IEEE, 2022) Beloso Legarra, Javier; Cruz Blas, Carlos Aristóteles de la; López Martín, Antonio; Institute of Smart Cities - ISC
The analysis, design and experimental characterization of a single-stage class-AB operational transconductance amplifier (OTA) with enhanced large- and small-signal performance is presented. The OTA is biased in weak inversion to save power and employs a non-linear current mirror as active load, leading a boosting current directly at the output branch. As a result, the amplifier's performance is improved without additional circuit elements and/or power consumption. A chip prototype has been fabricated in a 180-nm CMOS process, consuming a quiescent power of 2.5 µW from a supply voltage of ±0.5 V and a silicon area of 0.0013 mm 2 . For a load of 160 pF, it exhibits an average slew rate of 0.94 V/µs and a gain-bandwidth product of 22.1 kHz.
Open Access
AC coupled amplifier with a resistance multiplier technique for ultra-low frequency operation
(Elsevier, 2022) Martincorena Arraiza, Maite; Cruz Blas, Carlos Aristóteles de la; Carlosena García, Alfonso; López Martín, Antonio; Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio Ingeniaritzaren; Institute of Smart Cities - ISC; Ingeniería Eléctrica, Electrónica y de Comunicación; Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa
This paper proposes a novel, tunable AC coupled capacitive feedback amplifier, exhibiting an ultra-low high pass corner frequency. This is accomplished by actively boosting the output resistive value of a MOS transistor in weak inversion. The circuit is based on a more general architecture, recently proposed by the authors, and is analyzed in terms of its capability to achieve ultra-low frequency operation, its DC performance, and noise. The proposed technique is demonstrated via measurement results from a fabricated test chip prototype using a standard 0.18 µm CMOS technology. The proposed amplifier provides a tunable high pass corner frequency from 20 mHz to 475 mHz, consuming 4.71 μW and a total area of 0.069 mm2.
Open Access
Enhanced single-stage folded cascode OTA suitable for large capacitive loads
(IEEE, 2018) López Martín, Antonio; Garde Luque, María Pilar; Algueta-Miguel, Jose M.; Cruz Blas, Carlos Aristóteles de la; Carvajal, Ramón G.; Ramírez-Angulo, Jaime; Institute of Smart Cities - ISC
An enhanced single-stage folded cascode operational transconductance amplifier able to drive large capacitive loads is presented. Circuits that adaptively bias the input differential pair and the current folding stage are employed, which provide class AB operation with dynamic current boosting and increased gainbandwidth (GBW) product. Measurement results of a test chip prototype fabricated in a 0.5-µm CMOS process show an increase in slew rate and GBW by a factor of 30 and 15, respectively, versus the class A version using the same supply voltage and bias currents. Overhead in other performance metrics is small.
Open Access
Wide-swing class AB regulated cascode current mirror
(IEEE, 2020) Garde Luque, María Pilar; López Martín, Antonio; Cruz Blas, Carlos Aristóteles de la; Carvajal, Ramón G.; Ramírez-Angulo, Jaime; Institute of Smart Cities - ISC
A micropower regulated cascode CMOS current mirror is presented, combining floating gate and quasi floating gate MOS transistors to achieve both wide swing and class AB operation, respectively. Measurement results for a 0.5 μm CMOS test chip prototype are included, showing that the current mirror can provide a THD at 100 kHz of -44 dB for a supply voltage of ±0.75 V and input current amplitudes 20 times larger than the bias current.
Open Access
Low-power wide-bandwidth CMOS indirect current feedback instrumentation amplifier
(Elsevier, 2020) Carrillo, Juan M.; Domínguez, Miguel Á.; Pérez Aloe, Raquel; Cruz Blas, Carlos Aristóteles de la; Duque Carrillo, J. Francisco; Ingeniería Eléctrica, Electrónica y de Comunicación; Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio Ingeniaritzaren
The analysis and design trade-offs of a simple and economical technique to implement wideband low-voltage CMOS instrumentation amplifiers (IAs) based on indirect current feedback (ICF), are described. The input and an output transconductors consist of two super-source-followers and a resistor. As a result, the overall performance of the IA is enhanced. A thorough analysis of the proposed technique provided valuable insight on its operation. Two different realizations in 0.35-μm CMOS technology of an IA operating with a supply voltage of 3 V, are presented. In particular, a wide bandwidth single-stage IA with fixed voltage gain equal to 50 V/V and a low-power two-stage IA with externally programmable voltage gain, have been designed and characterized by extensive simulations. The simulated results of both circuits showed an improved response in terms of bandwidth, noise and power consumption, while their overall performance is comparable to other proposed approaches in terms of common-mode rejection ratio (CMRR) and linearity (THD).
Open Access
Design of low-cost smart accelerometers
(Universitat Politècnica de Catalunya, 2005) Carlosena García, Alfonso; López Martín, Antonio; Massarotto, Marco; Cruz Blas, Carlos Aristóteles de la; Lecumberri Villamediana, Pablo; Gómez Fernández, Marisol; Pintor Borobia, Jesús María; Gárriz Sanz, Sergio; Ingeniería Eléctrica y Electrónica; Matemáticas; Ingeniería Mecánica, Energética y de Materiales; Ingeniaritza Elektrikoa eta Elektronikoa; Matematika; Mekanika, Energetika eta Materialen Ingeniaritza
The goal of this project is to design a low-cost smart accelerometer, making use of a piezoelectric element as basic sensing material, and adding a mixed-mode conditioning circuit.
Open Access
Micropower class AB low-pass analog filter based on the super-source follower
(IEEE, 2022) Martincorena Arraiza, Maite; Cruz Blas, Carlos Aristóteles de la; López Martín, Antonio; Carlosena García, Alfonso; Institute of Smart Cities - ISC
An improved class AB version of the super source follower is used to implement a compact and power-efficient second order analog low-pass filter. The proposed circuit achieves a 41% power reduction as well as an improvement in linearity and pass band gain with respect to its class A counterpart. Measurement results of a test chip prototype fabricated in a 180 nm CMOS technology show a power consumption ranging from 50.3 μW to 85.27 μW for cutoff frequencies from 600 kHz to 890 kHz, with a supply voltage of ±0.75 V. A third order intermodulation distortion of −35.34 dB (for an input signal of 0.4 mV pp and 350 kHz) and a THD of −69.7 dB (for an input signal of 0.4 mV pp and 100 kHz) are measured, which results in an improvement with respect to the conventional class A version of 13.98 dB and 43.6 dB, respectively. The silicon area is 0.0592 mm 2 (using external capacitors).
Open Access
Fault detection of planetary gears based on signal space constellations
(MDPI, 2022) Martincorena Arraiza, Maite; Cruz Blas, Carlos Aristóteles de la; López Martín, Antonio; Molina Vicuña, Cristian; Matías Maestro, Ignacio; Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio Ingeniaritzaren; Institute of Smart Cities - ISC; Ingeniería Eléctrica, Electrónica y de Comunicación
A new method to process the vibration signal acquired by an accelerometer placed in a planetary gearbox housing is proposed, which is useful to detect potential faults. The method is based on the phenomenological model and consists of the projection of the healthy vibration signals onto an orthonormal basis. Low pass components representation and Gram–Schmidt’s method are conveniently used to obtain such a basis. Thus, the measured signals can be represented by a set of scalars that provide information on the gear state. If these scalars are within a predefined range, then the gear can be diagnosed as correct; in the opposite case, it will require further evaluation. The method is validated using measured vibration signals obtained from a laboratory test bench.