Person:
López Martín, Antonio

person.page.identifierURI

https://academica-e.unavarra.es/handle/2454/49446

Last Name

López Martín

First Name

Antonio

person.page.departamento

Ingeniería Eléctrica, Electrónica y de Comunicación

person.page.instituteName

ISC. Institute of Smart Cities

ORCID

0000-0001-7629-0305

person.page.upna

2254

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Now showing 1 - 10 of 39

Open Access
Energy-efficient amplifiers based on quasi-floating gate techniques
(MDPI, 2021) López Martín, Antonio; Garde Luque, María Pilar; Algueta-Miguel, Jose M.; Beloso Legarra, Javier; González Carvajal, Ramón; Ramírez-Angulo, Jaime; Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio Ingeniaritzaren; Institute of Smart Cities - ISC; Ingeniería Eléctrica, Electrónica y de Comunicación
Energy efficiency is a key requirement in the design of amplifiers for modern wireless applications. The use of quasi-floating gate (QFG) transistors is a very convenient approach to achieve such energy efficiency. We illustrate different QFG circuit design techniques aimed to implement low-voltage energy-efficient class AB amplifiers. A new super class AB QFG amplifier is presented as a design example including some of the techniques described. The amplifier has been fabricated in a 130 nm CMOS test chip prototype. Measurement results confirm that low-voltage ultra low power amplifiers can be designed preserving at the same time excellent small-signal and large-signal performance.
Open Access
±0.25 V Class-AB CMOS capacitance multiplier and precision rectifiers
(IEEE, 2019) Pourashraf, Shirin; Ramírez-Angulo, Jaime; Hinojo Montero, José María; González Carvajal, Ramón; López Martín, Antonio; Ingeniería Eléctrica y Electrónica; Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio Ingeniaritzaren
Reduction of minimum supply requirements is a crucial aspect to decrease the power consumption in VLSI systems. A high performance capacitance multiplier able to operate with supplies as low as ±0.25 V is presented. It is based on adaptively biased class-AB current mirrors which provide high current efficiency. Measurement results of a factor 11 capacitance multiplier fabricated in 180 nm CMOS technology verify theoretical claims. Moreover, low-voltage precision rectifiers based on the same class-AB current mirrors are designed and fabricated in the same CMOS process. They generate output currents over 100 times larger than the quiescent current. Both proposed circuits have 300 nW static power dissipation when operating with ±0.25 V supplies.
Open Access
Smart charging station with photovoltaic and energy storage for supplying electric buses
(IEEE, 2022) Berrueta Irigoyen, Alberto; Astrain Escola, José Javier; Puy Pérez de Laborda, Guillermo; El Hamzaoui, Ismail; Ursúa Rubio, Alfredo; Sanchis Gúrpide, Pablo; Villadangos Alonso, Jesús; Falcone Lanas, Francisco; López Martín, Antonio; Matías Maestro, Ignacio; Institute of Smart Cities - ISC
A Smart Charging Station (SCS) has been installed in the Public University of Navarre, Spain, in the framework of the H2020 Smart City Lighthouse STARDUST project. The SCS consists of a high-power electric bus charging point (300 kW), a 100 kW photovoltaic system, a 84 kWh support energy storage system based on a second-life lithiumion battery, and a monitoring and control system that allows the safe storage and convenient access to operation data. This SCS operates as a Smart Grid, being able to provide the power peaks required by the electric bus charger, reducing and smoothing the power demanded from the distribution grid and increasing the renewable energy self-consumption rate. This contribution presents a novel monitoring and control system, which is a key tool to integrate this SCS in the data infrastructure of a Smart City, as well as an energy management system able to operate the SCS to achieve the above-mentioned technical requirements. The crucial role of the monitoring and control system and the energy management system becomes evident in this work.
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
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
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
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
Super class AB RFC OTA with adaptive local common-mode feedback
(Institution of Engineering and Technology, 2018) Garde Luque, María Pilar; López Martín, Antonio; Carvajal, Ramón G.; Ramírez-Angulo, Jaime; Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio Ingeniaritzaren; Institute of Smart Cities - ISC; Ingeniería Eléctrica, Electrónica y de Comunicación
A super class AB recycling folded cascode operational transconductance amplifier is presented. It employs local common-mode feedback using two matched tuneable active resistors, allowing to adapt the amplifier to different process variations and loads. Measurement results from a test chip prototype fabricated in a 0.5 μm CMOS process validate the proposal.
Open Access
Power-efficient single-stage class-AB OTA based on non-linear nested current mirrors
(IEEE, 2023) Beloso Legarra, Javier; Cruz Blas, Carlos Aristóteles de la; López Martín, Antonio; Institute of Smart Cities - ISC
A novel approach to design low-power area-efficient rail-to-rail output single-stage class-AB operational transconductance amplifiers (OTAs) with enhanced large- and small-signal performance to drive large capacitive loads is presented. It is based on a non-linear nested current mirror at the active load of a splitted differential input pair biased in weak inversion that boosts dynamic currents beyond their quiescent value directly at the output branch. As a result, slew rate, DC gain, gainbandwidth product, settling time and noise performance are improved without additional circuit elements or power consumption. An OTA prototype has been fabricated in a 180-nm CMOS process, consuming a quiescent power of 2.9 µW from a supply voltage of ±0.5 V and a silicon area of 0.001 mm2 . Measurement results validate the advantages of the proposal, exhibiting positive and negative slew rates of 110 V/ms and −58 V/ms, respectively, and a gain-bandwidth product of 136 kHz with a phase margin of 90◦ for a capacitive load of 160 pF.
Open Access
Class AB amplifier with enhanced slew rate and GBW
(John Wiley & Sons, 2019) Garde Luque, María Pilar; López Martín, Antonio; Algueta-Miguel, Jose M.; Ramírez-Angulo, Jaime; González Carvajal, Ramón; Ingeniería Eléctrica y Electrónica; Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio Ingeniaritzaren
The design of a micropower class AB operational transconductance amplifier with large dynamic current to quiescent current ratio is addressed. It is based on a compact and power-efficient adaptive biasing circuit and a class AB current follower using the Quasi-Floating Gate (QFG) technique. The amplifier has been designed and fabricated in a 0.5 um CMOS process. Simulation and measurement results show a slew rate (SR) improvement factor versus the class A version larger than 4 for the same supply voltage and bias currents, as well as enhanced small-signal performance.