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Author

Ramon G. Carvajal

Other affiliations: Epson, New Mexico State University
Bio: Ramon G. Carvajal is an academic researcher from University of Seville. The author has contributed to research in topics: CMOS & Operational amplifier. The author has an hindex of 32, co-authored 287 publications receiving 4721 citations. Previous affiliations of Ramon G. Carvajal include Epson & New Mexico State University.


Papers
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Journal ArticleDOI
TL;DR: A design example showing the application of the FVF to build systems based on translinear loops is described which shows the potential of this cell for the design of high-performance low-power/low-voltage analog and mixed-signal circuits.
Abstract: In this paper, a basic cell for low-power and/or low-voltage operation is identified. It is evidenced how different versions of this cell, coined as "flipped voltage follower (FVF)" have been used in the past for many applications. A detailed classification of basic topologies derived from the FVF is given. In addition, a comprehensive list of recently proposed low-voltage/low-power CMOS circuits based on the FVF is given. Although the paper has a tutorial taste, some new applications of the FVF are also presented and supported by a set of simulated and experimental results. Finally, a design example showing the application of the FVF to build systems based on translinear loops is described which shows the potential of this cell for the design of high-performance low-power/low-voltage analog and mixed-signal circuits.

622 citations

Proceedings ArticleDOI
07 Aug 2002
TL;DR: In this article, a new basic cell for low power and/or lowvoltage operation is identified, which is called flipped voltage follower (FVF) and it is shown that different versions of this cell, called FVF, have been used in the past for different applications.
Abstract: In this paper a new basic cell for low-power and/or low-voltage operation is identified. It is shown that different versions of this cell, called "flipped voltage follower", have been used in the past for different applications. New circuits using this cell are also proposed here.

284 citations

Journal ArticleDOI
TL;DR: In this paper, a simple technique to achieve lowvoltage power-efficient class AB operational transconductance amplifiers (OTAs) is presented, which is based on the combination of class AB differential input stages and local commonmode feedback (LCMFB) which provides additional dynamic current boosting, increased gain-bandwidth product (GBW), and near-optimal current efficiency.
Abstract: A simple technique to achieve low-voltage power-efficient class AB operational transconductance amplifiers (OTAs) is presented. It is based on the combination of class AB differential input stages and local common-mode feedback (LCMFB) which provides additional dynamic current boosting, increased gain-bandwidth product (GBW), and near-optimal current efficiency. LCMFB is applied to various class AB differential input stages, leading to different class AB OTA topologies. Three OTA realizations based on this technique have been fabricated in a 0.5-/spl mu/m CMOS technology. For an 80-pF load they show enhancement factors of slew rate and GBW of up to 280 and 3.6, respectively, compared to a conventional class A OTA with the same 10-/spl mu/A quiescent currents and /spl plusmn/1-V supply voltages. In addition, the overhead in terms of common-mode input range, output swing, silicon area, noise, and static power consumption, is minimal.

282 citations

Journal ArticleDOI
TL;DR: In this paper, a design principle for very low-voltage analog signal processing in CMOS technologies is presented, based on the use of quasi-floating gate (QFG) MOS transistors.
Abstract: A novel design principle for very low-voltage analog signal processing in CMOS technologies is presented. It is based on the use of quasi-floating gate (QFG) MOS transistors. Similar to multiple input floating gate (MIFG) MOS transistors, a weighted averaging of the inputs accurately controlled by capacitance ratios can be obtained, which is the basic operating principle. Nevertheless, issues often encountered in MIFG structures, such as the initial charge trapped in the floating gates or the gain-bandwidth product degradation, are not present in QFG configurations. Several CMOS circuit realizations using open- and closed-loop topologies, have been designed. They include analog switches, mixers, programmable-gain amplifiers, track and hold circuits, and digital-to-analog converters. All these circuits have been experimentally verified, confirming the usefulness of the proposed technique for very low-voltage applications.

234 citations

Journal ArticleDOI
TL;DR: A simple and efficient low-voltage two-stage operational amplifier with Class-AB output stage with large effective output current boosting factor and close to a factor 2 bandwidth enhancement is introduced.
Abstract: A simple and efficient low-voltage two-stage operational amplifier with Class-AB output stage is introduced. It has a large effective output current boosting factor (/spl sim/50) and close to a factor 2 bandwidth enhancement. This is achieved at the expense of minimum increase in circuit complexity and no additional static power dissipation. Experimental verification of the characteristics of the proposed circuit is provided.

131 citations


Cited by
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01 Jan 2016
TL;DR: The design of analog cmos integrated circuits is universally compatible with any devices to read and is available in the book collection an online access to it is set as public so you can download it instantly.
Abstract: Thank you for downloading design of analog cmos integrated circuits. Maybe you have knowledge that, people have look hundreds times for their chosen books like this design of analog cmos integrated circuits, but end up in malicious downloads. Rather than enjoying a good book with a cup of coffee in the afternoon, instead they juggled with some harmful virus inside their computer. design of analog cmos integrated circuits is available in our book collection an online access to it is set as public so you can download it instantly. Our digital library spans in multiple countries, allowing you to get the most less latency time to download any of our books like this one. Kindly say, the design of analog cmos integrated circuits is universally compatible with any devices to read.

1,038 citations

Journal ArticleDOI
TL;DR: A design example showing the application of the FVF to build systems based on translinear loops is described which shows the potential of this cell for the design of high-performance low-power/low-voltage analog and mixed-signal circuits.
Abstract: In this paper, a basic cell for low-power and/or low-voltage operation is identified. It is evidenced how different versions of this cell, coined as "flipped voltage follower (FVF)" have been used in the past for many applications. A detailed classification of basic topologies derived from the FVF is given. In addition, a comprehensive list of recently proposed low-voltage/low-power CMOS circuits based on the FVF is given. Although the paper has a tutorial taste, some new applications of the FVF are also presented and supported by a set of simulated and experimental results. Finally, a design example showing the application of the FVF to build systems based on translinear loops is described which shows the potential of this cell for the design of high-performance low-power/low-voltage analog and mixed-signal circuits.

622 citations

Journal ArticleDOI
TL;DR: In this paper, a fully integrated programmable biomedical sensor interface chip dedicated to the processing of various types of biomedical signals is presented. But the chip, optimized for high power efficiency, contains a low noise amplifier, a tunable bandpass filter, a programmable gain stage, and a successive approximation register analog-to-digital converter.
Abstract: This paper presents a fully integrated programmable biomedical sensor interface chip dedicated to the processing of various types of biomedical signals. The chip, optimized for high power efficiency, contains a low noise amplifier, a tunable bandpass filter, a programmable gain stage, and a successive approximation register analog-to-digital converter. A novel balanced tunable pseudo-resistor is proposed to achieve low signal distortion and high dynamic range under low voltage operations. A 53 nW, 30 kHz relaxation oscillator is included on-chip for low power consumption and full integration. The design was fabricated in a 0.35 mum standard CMOS process and tested at 1 V supply. The analog front-end has measured frequency response from 4.5 mHz to 292 Hz, programmable gains from 45.6 dB to 60 dB, input referred noise of 2.5 muVrms in the amplifier bandwidth, a noise efficiency factor (NEF) of 3.26, and a low distortion of less than 0.6% with full voltage swing at the ADC input. The system consumes 445 nA in the 31 Hz narrowband mode for heart rate detection and 895 nA in the 292 Hz wideband mode for ECG recording.

390 citations

Journal ArticleDOI
TL;DR: In this paper, some of the issues facing analog designers in implementing low voltage circuits are discussed, and possible low voltage design techniques are examined, along with their merits and demerits.
Abstract: Analog signal processing is fast and can address real world problems. The applications of battery powered analog and mixed mode electronic devices require designing analog circuits to operate at low voltage levels. In this paper, some of the issues facing analog designers in implementing low voltage circuits are discussed, and possible low voltage design techniques are examined. The authors describe briefly almost all low voltage design techniques suitable for analog circuit structures along with their merits and demerits.

299 citations

Proceedings ArticleDOI
07 Aug 2002
TL;DR: In this article, a new basic cell for low power and/or lowvoltage operation is identified, which is called flipped voltage follower (FVF) and it is shown that different versions of this cell, called FVF, have been used in the past for different applications.
Abstract: In this paper a new basic cell for low-power and/or low-voltage operation is identified. It is shown that different versions of this cell, called "flipped voltage follower", have been used in the past for different applications. New circuits using this cell are also proposed here.

284 citations