Preprocessing of data before transmission is recommended for many sensor network applications to reduce communication and improve energy efficiency. However, constraints on memory, speed, currently limit the processing capabilities within a network. In this paper, we describe how ultra-low-power analog circuitry can be integrated with nodes create energy-efficient networks. To demonstrate concept, present custom front-end which performs spectral analysis at fraction power used by digital...

Analog filter banks befit remote audio- and vibration-sensing applications, which require frequency analysis to be performed with low-power consumption moderate-to-high precision. The precision of a bank depends on both the signal-path (i.e., dynamic range) also parameter (e.g., accuracy center frequencies). This brief presents new bandpass for audio-frequency provides procedure designing this filter. is used in 16-channel has been fabricated 0.35- CMOS process. range exceeding 62 dB...

Magnitude detection, such as envelope detection or RMS estimation, is needed for many low-power signal-analysis applications. In applications, the temporal accuracy of magnitude detector important its amplitude accuracy. We present a audio-frequency that simultaneously achieves both high and This performance achieved by rectifying signal with high-ripple peak then averaging this rectified an adaptive-time-constant filter. The time constant filter decreases increasing amplitude, enabling to...

Flash memory is an important component in many embedded system-on-a-chip applications, which drives the need to generate high write/erase voltages generic CMOS processes. In this paper, we present a regulated, high-voltage charge pump for erasing and floating-gate transistors. This 0.069-mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> was fabricated 0.35 μm standard process. While operating from 2.5 V supply, generates regulated up 16...

We present a programmable, continuous-time bandpass filter that is extremely compact, power efficient, and can cover wide range of frequencies (10 Hz-10 MHz). This capacitively coupled current conveyor ( <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">C</i> <sup xmlns:xlink="http://www.w3.org/1999/xlink">4</sup> ) has second-order transfer function capable being used as basic bandpass-filter element to create high-order filters. The use...

Floating-gate (FG) transistors are useful for precisely programming a large array of current sources. Present FG techniques require disconnection the transistor from rest its circuit while it is being programmed. We present new method that does not this disconnection. In indirect method, two share allowing one to exist directly in other reserved programming. Since need be disconnected program it, switch count reduced, resulting fewer parasitics and better overall performance. Additionally,...

In this paper, we propose a real-time noise suppression system implemented with analog VLSI. The algorithm is designed to reduce stationary background while preserving the non-stationary signal component. Because relies on computation rather than digital, it has benefits such as extremely low power consumption and computation. based digital processing foundations that are slightly adjusted for use in continuous-time domain. components described part of include C/sup 4/ second-order section...

As an apt choice for long-term analog memory in standard CMOS processes, floating-gate transistors are key enablers large-scale programmable systems. Such systems often designed battery-powered-and generally resource-constrained-applications, which require the cells to program quickly with low infrastructural overhead. In order meet these needs, we present a new cell. Our four-transistor cell offers both voltage and current outputs has linear injection tunneling characteristics. Furthermore,...

The requirements of many wireless sensing applications approach, or even exceed, the limited hardware capabilities energy-constrained platforms. To achieve such demanding requirements, some platforms have included low-power application-specific hardware---at expense generality---to pre-process sensor data for reduction to only relevant information. While this additional can save power by reducing activity microcontroller and radio, a unique solution is required each application, which...

This paper describes our current efforts toward creating cooperative analog-digital signal-processing systems for auditory sensor and applications. We address resolution issues that affect the choice of algorithms arriving from an analog sensor. discuss circuit approaches front-end signal processing by reviewing major programmable building blocks showing how they can be interconnected to create a complete system. also IC using this technology noise suppression, as well system speech...

The capacitively-coupled current conveyer second-order section (C/sup 4/ SOS) is a continuous-time bandpass filter with electronically tunable corner frequencies and /spl plusmn/40 dB/decade or greater roll offs. can be set independently of each other, the bandwidth therefore tuned at will. Each have its own Q peak or, if corners are brought close together, very tight single develops. This leads to further isolation any given frequency thus useful for signal processing applications. An array...

This paper presents an overview of floating-gate transistors with emphasis on using them as programmable elements to correct mismatch inherent in analog circuit design. The design methodology is such that MOSFETs play the role while forming part circuitry interest, well. Such approach results a compact architecture minimal additional power. Accurate programming key successful implementation discussed along experimental demonstrating charge retention. An several examples provided demonstrate...

Floating-gate transistors are increasingly used for digital and/or analogue non-volatile memory in standard CMOS integrated circuits. The mask design of the floating-gate's tunnelling junction, where erasure writing occur, is examined. Aided by static and transient current measurements a variety junctions, recommendations constructing these junctions to minimise duration, power consumption oxide degradation programming presented.

We present a field-programmable analog array (FPAA) for sensor interfacing and information extraction in wireless, resource-constrained applications. Ultra-low-power operation is achieved through low-overhead reprogramming an efficient processing architecture. demonstrate reconfigurability performance the synthesis of temperature sensor, heart-rate alarm, audio spectrum normalizer, which have measured full-system power consumptions 12μW, 20μW, 17.25μW, respectively.

Floating-gate transistors are useful for precisely programming a large array of current sources. Present floating-gate techniques require disconnection the transistor from rest its circuit to be programmed. We present new method indirectly that does not this disconnection. Two share floating gate allowing one exist directly in while other is reserved programming. Since need disconnected program it, switch count reduced, resulting fewer parasitics and better overall performance.

In this paper, we present a regulated charge pump with extremely low output ripple (&lt;1 mV) that can be used for accurate programming of nonvolatile memory. We technique to include low-drop-out regulator inside the charge-pump regulation loop reduce ripple. This was fabricated in 0.35 μ m standard CMOS process. The die area is 0.163 mm 2 . While operating from 2.5 V supply, generates voltages up 10 V.

While LTS and HTS SQUIDs have successfully been applied in the detection of flaws aircraft grade aluminium structures for well over a decade, interest has recently spread to type new material, namely composites. One example, carbon fibre reinforced polymer (CFRP), is increasingly being favoured by industry because its strength weight ratio fact that it corrosion-resistant. Material defect characterization using still at an early stage, but due expected rapid expansion use such materials,...

A technique is introduced to enable the simulation of floating-gate transistors within standard analogue circuit simulators, such as SPICE. This can be used in all types simulations, ranging from DC sweeps charge-modification scenarios. The then simulate several circuits, results which show strong agreement with identical circuits fabricated CMOS processes.

The limited power budgets of sensor networks necessitate in-network pre-processing to reduce communication overhead. low consumption analog signal processing (ASP) is well-suited for this task. However, adoption ASP restrained by the longer design time relative reconfigurable/reprogrammable digital processing. Our solution enable reconfiguration through use a field-programmable array (FPAA), which allows wireless network developers rapidly prototype and test designs. In paper, we present an...

The wireless sensor nodes used in a growing number of remote sensing applications are deployed inaccessible locations or subjected to severe energy constraints. Audio-based offers flexibility node placement and is popular low-power schemes. Thus, this paper, architecture with low power consumption in-the-field reconfigurability evaluated the context an acoustic vehicle detection classification (hereafter “AVDC”) scenario. proposed utilizes always-on field-programmable analog array (FPAA) as...

This brief presents a linearization method for the voltage-to-current (V-to-I) stage of voltage-controlled oscillators (VCOs). A floating-gate transistor is utilized at VCO's input as low-overhead V-to-I linearization. The resulting VCO ring oscillator with an extended linear voltage-to-frequency range. (RO-VCO) has also been included in VCO-based analog-to-digital converter (VCO-ADC) to showcase how technique can be leveraged improve system performance. measured results from linearized...

In order to meet the demands of low-power real-time audio signal processing, we present a programmable array bandpass filters using floating-gate transistors. This bank analog can be placed before an analog-to-digital converter perform frequency decomposition and also allow for preprocessing being transformed into digital domain. Individual filter taps easily tuned any given bandwidth because capacitively coupled current conveyers (C/sup 4/s) are used with transistors as biasing elements....

We present an integrated analog signal processor for resource-constrained sensing applications, such as wireless sensor networks, wherein sensors are remotely deployed in inaccessible locations. The processor, which is reconfigurable and operates at 27.8μW, extends the capabilities of nodes by performing spectral analysis event detection low-power circuits. performance IC demonstrated example application (i.e. vehicle classification).

Wearable medical devices, wireless sensor networks, and other energy-constrained sensing devices are often concerned with finding specific data within more-complex signals while maintaining low power consumption. Traditional analog-to-digital converters (ADCs) can capture the information at a high resolution to enable subsequent digital system process for desired data. However, traditional ADCs be inefficient applications that only require points of This work offers an alternative path lower...

Transconductance amplifier capacitor oscillators (TACOs) readily produce phase-shifted sinusoids with low distortion over a wide frequency range. Hence, TACOs can be used in applications including telecommunications and lock-in amplifiers. The precise amplitude regulation needed such necessitates an automatic gain controller (AGC) envelope detector. detectors have frequency-dependent nonidealities which complicate AGC design incite modulation outside limited This brief presents VCO that uses...