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This paper presents both a complete set of very low-voltage basic building blocks and a compact design methodology for log filtering in standard or even digital CMOS technologies. The new proposals are based on an alternative translinear loop principle for the MOSFET operating in its subthreshold region. Three different sets of complete basic building blocks are proposed along with all required auxiliary circuitry and a specific matrix design procedure to obtain stable and compact filter implementations. Also, all-MOS filter implementations following these circuit techniques are studied. Simulated and experimental examples are given at 1-V supply voltage for 1.2- and 0.35-pm CMOS technologies. The resulting circuit techniques are suitable to integrate very low-voltage low-power system-on-a-chip audio applications, such as hearing aids, in standard CMOS technologies. [ABSTRACT FROM AUTHOR]

This paper presents a low-power and fully integrated frontend channel for long-wave infrared spectroscopic gas recognition. The proposed channel circuitry includes: input sensor biasing, sub-Hz high-pass filtering and preamplification, differential blind cancellation, and lock-in A/D conversion. The proposed CMOS circuits make extensive use of transistor subthreshold operation and digital programmability. Experimental results are presented for a 0.3 mm^2 400 \muW channel prototype integrated in 0.35 \mum CMOS technology. [ABSTRACT FROM PUBLISHER]

This paper presents a very low-power and fully programmable CMOS digital active pixel sensor for uncooled IR fast imaging. The proposed circuit topology includes self-biasing, built-in input capacitance compensation, predictive A/D conversion, and a truly digital I/O interface, all at pixel level. Furthermore, full fixed pattern noise cancellation is also supplied by the external digital tuning of both offset and gain for each individual pixel at no speed costs. Two DPS circuit implementations for IR PbSe sensors have been integrated in standard 0.35-μm 2-polySi 4-metal CMOS technology. Finally, exhaustive experimental results from their electrical tests are reported to validate the proposed DPS design techniques. [ABSTRACT FROM AUTHOR]

This paper presents a new family of Class-AB operational transconductance amplifier (OTA) circuits based on single-stage topologies with non-linear current amplifiers. The proposed variable-mirror amplifier (VMA) architecture is mainly characterized by generating all Class-AB current in the output transistors only, by exhibiting very low sensitivity to both technology and temperature deviations, and by avoiding the need for any internal frequency-compensation mechanism. Hence, this family of OTAs is well-suited for low-power switched-capacitor circuits and specifically optimized for switched-OpAmp fast on-off operation and multi-decade load-capacitance specifications. Analytical expressions valid in all regions of operation are presented to minimize VMA settling time in discrete-time circuits. Also, a complete OTA design example integrated in 0.18 \mu\textm 1P6M MiM 1.8 V CMOS technology is supplied with detailed simulation and experimental results. Compared to resistor-free state-of-art Class-AB OpAmp and OTA literature, the proposed architecture returns the highest measured figure-of-merit value. [ABSTRACT FROM PUBLISHER]

This paper presents a low-power all-MOS delta-sigma ADC specifically optimized for the potentiostatic biasing and amperometric read-out of electrochemical sensors. The proposed architecture reuses the dynamic properties of the sensor itself to implement a continuous-time mixed electrochemical delta-sigma modulator with minimalist analog circuits fully integrable in purely digital CMOS technologies. A 25-µW smart electrochemical sensor demonstrator integrated in low-cost 1M CMOS technology with Au post-processing is presented. Experimental results show electrical dynamic range values exceeding 10-bit, while electrochemical figures exhibit linearity levels close to R² = 0.999 combined with RSD < 15% in terms of reproducibility. A comparative test with commercial potentiostat equipment is also included to qualify the performance of the proposed ADC. [ABSTRACT FROM PUBLISHER]

A low-power multichannel CMOS digital read-out IC (ROTC). for differential piezo-resistive sensing is presented as part of the positioning system of a liquid dispensing MEMS. New very low-voltage and single-battery compatible CMOS circuits are proposed for digital gain tuning, pre-amplification, and integrating A/D conversion. Overall low-power consumption is achieved by operating the key devices in subthreshold in order to prevent from heating the fluidic MEMS. A complete quad-channel ROIC has been integrated in 0.35-μm CMOS 2-polySi 4-metal technology. The reported experimental results agree with the electrical simulations. [ABSTRACT FROM AUTHOR]