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

Full item page

Search Results

Now showing 1 - 10 of 10

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
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
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
A 1.2-V current-mode RMS-to-DC converter based on a novel two-quadrant electronically simulated MOS translinear loop
(IEEE, 2020) Martincorena Arraiza, Maite; Cruz Blas, Carlos Aristóteles de la; Algueta-Miguel, Jose M.; López Martín, Antonio; Institute of Smart Cities - ISC
A novel current-mode CMOS RMS-to-DC converter using translinear techniques is introduced. It is based on a squarer/divider cell that is implemented using an electronically simulated loop with a novel biasing scheme that allows its operation in two quadrants. The cell is designed using a differential input current and a small signal first order filter to implement the voltage averaging, leading to a compact solution that can be used with low voltage supplies. The converter has been fabricated in a standard 130-nm CMOS process, and measurement results are provided to demonstrate the feasibility of the system.
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
Gain-boosted super class AB OTAs based on nested local feedback
(IEEE, 2021) Beloso Legarra, Javier; Cruz Blas, Carlos Aristóteles de la; López Martín, Antonio; Ramírez-Angulo, Jaime; Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio Ingeniaritzaren; Institute of Smart Cities - ISC; Ingeniería Eléctrica y Electrónica
A new approach to design super class AB operational transcon-ductance amplifiers (OTAs) with enhanced large-signal and small-signal performance is presented. It is based on employing two nested positive and negative feedback loops at the active load of an adaptively biased differential pair in weak inversion region. As a result, DC gain, gain-bandwidth product, settling time and noise are improved compared to conventional super class AB OTAs without extra circuit nodes or power consumption. Measurement results of a 180 nm CMOS test chip prototype show a current boosting factor higher than 5000 and a nearly ideal current efficiency. Due to the ultra-low quiescent currents and high driving capability, the circuit exhibits an excellent large-signal figure-of-merit (FOML) of 236 V-1. To illustrate the applicability of the proposed approach, a differential sample-and-hold (S/H) circuit was designed and fabricated on the same test chip. Measurement results of the S/H validate the advantages of the proposal.
Open Access
A family of alternating current amplifiers for ultra-low frequency operation
(Wiley, 2021) Martincorena Arraiza, Maite; Carlosena García, Alfonso; Cruz Blas, Carlos Aristóteles de la; Beloso Legarra, Javier; 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
A family of capacitively coupled alternating current (AC) amplifiers featuring ultra-low (below 1 Hz) corner frequency is presented. This is achieved by using high-gain devices which actively boost feedback resistance and thus reduce corner frequency. This procedure is often termed, though with a different purpose, as 'bootstrapping'. The proposed architectures are very general and admit several possible practical implementations. To demonstrate their usefulness, the circuits are implemented with two operational amplifiers (OA), but other active devices such as operational transconductance amplifiers (OTAs) can be alternatively used. All circuits have been theoretically analyzed, extensively simulated and measured, exhibiting high-pass cutoff frequencies as low as 30 mHz.
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.
Open Access
AC amplifiers with ultra-low corner frequency by using bootstrapping
(Institution of Engineering and Technology, 2021) Martincorena Arraiza, Maite; Carlosena García, Alfonso; Cruz Blas, Carlos Aristóteles de la; López Martín, Antonio; Ingeniería Eléctrica y Electrónica; Institute of Smart Cities - ISC; Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio Ingeniaritzaren
A novel architecture for an AC (i.e. high-pass) amplifier is proposed allowing a drastic reduction of the cutoff frequency to the sub-Hertz range. It builds upon the classic AC configuration with a high gain amplifier and a parallel RC circuit in the feedback loop, by increasing the feedback resistance through bootstrapping. Resistance multiplying factors higher than four orders of magnitude are easily achievable. The basic principle can be applied to several practical implementations, though in this letter it is demonstrate with measurement results of an op-amp based discrete implementation.