IEE Proceedings - Circuits, Devices and Systems

The author reviews the recent results obtained on the low-frequency noise characteristics of deep-submicron metal-oxide-semiconductor field-effect transistors (MOSFETs). The manuscript covers measurements, analysis and modelling of 1/f noise as well as random telegraph signals (RTS). In addition, techniques are presented where RTS and 1/f noise measurements can be utilised to characterise the oxid... View full abstract»

An updated version of a tutorial paper (see IEEE Circuits Devices Mag., vol. 2, no. 1, p. 20-32, 1985) on active filters using operational transconductance amplifiers (OTAs) is presented. The integrated circuit issues involved in active filters (using CMOS transconductance amplifiers) and the progress in this field in the last 15 years is addressed. CMOS transconductance amplifiers, nonlinearized ... View full abstract»

Novel CMOS realisations of a differential voltage current conveyor (DVCC) are described. These circuits are powerful building blocks, especially for applications demanding differential or floating inputs like impedance converter circuits and current mode instrumentation amplifiers. Applications suitable for VLSI are then considered by using the DVCC to realise a MOS transconductor and a continuous... View full abstract»

A design methodology for linear micro-generators is developed, and is applied to the design of a mm-scale electromagnetic micro-generator. The fabrication of a prototype device is also described using generally available microfabrication techniques, and the results of testing the device on a variable amplitude vibration source, in air and vacuum, are presented. The experimental results confirm the... View full abstract»

A piecewise linear recursive approximation scheme is applied to the computation of the sigmoid function and its derivative in artificial neurons with learning capability. The scheme provides high approximation accuracy with very low memory requirements. The recursive nature of this method allows for the control of the rate accuracy/computation-delay just by modifying one parameter with no impact o... View full abstract»

A low-noise amplifier (LNA) fabricated in a standard 0.35 μm AMS CMOS process is described. The LNA is part of a telemetry system which is part of a R&D project for biomedical applications. The goal is to build a low-power 174-230 MHz RF transmitter-receiver suitable for measuring blood pressure on a patient body. The low noise amplifier is composed of transistors only, which allows full integr... View full abstract»

A new analytic method for predicting the stray capacitance of a double layer coil with conducting shield and air core is presented. The method involves construction of a two-layer turn-to-turn circuit model, which includes the self-inductance and resistance of each turn, the mutual inductance representing the flux linkage between all turns, and the capacitance between adjacent turns and the capaci... View full abstract»

A novel current mirror (CM), suitable for operation at low voltage levels is presented. The mirror has high input and high output voltage swings. Adaptive current biasing is introduced for minimising the effects of offset current. A compensation technique has been used to increase the bandwidth. This makes the CM structure attractive for portable, high frequency circuit applications. P-SPICE simul... View full abstract»

Low-power design of VLSI circuits has been identified as a critical technological need in recent years due to the high demand for portable consumer electronics products. In this regard many innovative designs for basic logic functions using pass transistors and transmission gates have appeared in the literature recently. These designs relied on the intuition and cleverness of the designers, withou... View full abstract»

The authors present a new fully differential operational transconductance amplifier (OTA) for low-voltage and fast-settling switched-capacitor circuits in pure digital CMOS technology. The proposed two-stage OTA is a hybrid class A/AB that combines a folded cascode as the first stage with active current mirrors as the second stage. Owing to the class AB operation in the second stage, slew limiting... View full abstract»

The authors present two new filter biquads based on the recently introduced fully differential current conveyor (FDCCII). The biquads use a single FDCCII, two grounded resistors and two grounded capacitors, which are the minimum components necessary to realise a second-order filtering response (low-pass, high-pass, band-pass, band-reject, and all-pass). This is unlike biquads reported by El-Adawy ... View full abstract»

With the ongoing development of multimedia technology, the number of information systems containing image retrieval functions is increasing rapidly. Techniques of colour histogram content-based image retrieval are compared in terms of speed and efficiency, and a modified approach based on a composite colour image histogram processing is introduced. The proposed approach is fast and provides result... View full abstract»

A new approach to the design of fourth-order PLL loop filters is described. The technique allows the specification of a desired attenuation at a given offset frequency whilst maintaining the same loop natural frequency and phase margin as for a third-order loop filter. The benefit of this approach is that improved attenuation is obtained at wide frequency offsets, without compromising the in-band ... View full abstract»

The authors present a review of phase to sine amplitude conversion (PSAC) techniques for direct digital frequency synthesis (DDFS). Principles of DDFS are first considered, then approaches for the reduction of system complexity are identified. It is shown that the basic problem for the design of the phase to sine amplitude converter, whether the system has single phase or quadrature outputs, is th... View full abstract»

The authors present a fuzzy adaptive filtered-X algorithm for active noise cancellation (ANC) in ducts, using fuzzy rules to construct an anti-noise filter to cancel out the undesired noise. Complex acoustic plant models, such as those used in conventional ANC systems, can be disregarded in the proposed fuzzy technique. As a new method for ANC, the proposed system tunes the free parameters automat... View full abstract»

This study discusses the composite effect of channel length and gate oxide thickness scaling, coupled with the effect of gate dielectric nitridation on the 1/f noise of minimum channel length NMOS transistors. These transistors have been taken from four advance CMOS technologies with dual gate oxide thickness. The result shows that the current noise spectral density S/sub Id/ of a thin gate oxide ... View full abstract»

An efficient piecewise linear approximation of a nonlinear function (PLAN) is proposed. This uses a simple digital gate design to perform a direct transformation from X to Y, where X is the input and Y is the approximated sigmoidal output. This PLAN is then used within the outputs of an artificial neural network to perform the nonlinear approximation. The comparison of this technique with two othe... View full abstract»

A fixed-frequency modified (LCL-type) series-resonant converter which uses a capacitive output filter is analysed using the Fourier series approach. Based on the analysis a simple design procedure is given. Detailed SPICE simulation results are presented for the designed converter to evaluate its performance for varying input supply voltage and for load variation. Experimental results obtained fro... View full abstract»

The effect of radiation-induced changes on the characteristics of an n-channel MOSFET has been investigated theoretically. A one-dimensional semi-numerical model of the device has been developed which can estimate fairly accurate characteristics of the device under unirradiated and irradiated conditions. The effect of ionising radiation on the channel voltage and electric field profile in the chan... View full abstract»

The authors present a new versatile circuit building block called a differential difference current conveyor (DDCC). An IC technique for implementing the DDCC is also presented. The DDCC-based frequency-selective circuits and nonlinear building blocks such as multiplier, squarer and square rooter are developed. Experimental results are given to demonstrate the feasibility of the proposed technique... View full abstract»

The paper presents new low-power flip-flops which are faster compared to previously proposed structures. The single-edge-triggered flip-flop, called the MHLFF (modified hybrid latch flip-flop), reduces the power dissipation of the HLFF (hybrid latch flip-flop) by avoiding unnecessary node transitions. To reduce the power consumption of the flip-flop further, the double-edge-triggered modified hybr... View full abstract»

The authors describe an efficient method for designing current-mode group-delay equalisers. The method is based on introducing zeros into the right-hand s-plane by mirroring the poles of an LC ladder network. This is achieved by developing a current-mode model capable of implementing the pole-zero mirroring technique. Using multiple-output OTAs and grounded capacitors, the model is used to derive ... View full abstract»

A wideband voltage-controlled oscillator (VCO) with a frequency range from 830 MHz to 2.4 GHz is presented. The VCO has two control inputs, one for continuous control of the output frequency and one for band switching, and two quadrature outputs. Based on a 0.25 μm CMOS process, this VCO is simulated for the supply voltage of 2 V. A wide tuning range of 98% is obtained in two independent bands.... View full abstract»

An overview of theoretical 1/f noise models is given. Analytical expressions showing the device geometry and bias dependencies of 1/f noise in all conduction regimes are summarised. Novel experimental studies on 1/f noise in MOS transistors are presented with special emphasis on p-channel transistors from 90 nm CMOS technology. In addition to the noise in the drain terminal, the gate current noise... View full abstract»

A high-frequency fully differential CMOS operational transconductance amplifier (OTA) is presented for continuous-time filter applications in the megahertz range. The proposed design technique combines a linear cross-coupled quad input stage with an enhanced folded-cascode circuit to increase the output resistance of the amplifier. SPICE simulations show that DC-gain enhancement can be obtained wi... View full abstract»

Flat-panel X-ray image detectors have been shown to be suitable to replace the conventional X-ray film/screen cassettes for medical radiography (static or snapshot imaging). They are capable of capturing the X-ray image digitally immediately after the X-ray exposure which permits a convenient clinical transition to digital radiography. There are two general approaches to the flat-panel X-ray detec... View full abstract»

A parasitic-capacitance-insensitive MOSFET-C integrator and differentiator using operational transresistance amplifiers are proposed and experimental results demonstrated. The bandwidths of these circuits are also independent of their gains. The required capacitances are smaller than those in previous work. Two new configurations of universal current-mode biquad filters based on these circuits are... View full abstract»

The paper describes a method for the estimation of the equivalent circuit parameters for a millimetre-wave GaAs PIN diode switch. A GaAs PIN diode with low insertion loss over the millimetre-wave region is presented. The diode has been developed by estimating the parasitic resistance of the space between the P⁺-layer and the N⁺-electrode. The design and performance of a broad... View full abstract»

The design of basic passive LC networks, with particular attention to the ubiquitous II network, is studied for conjugate matching any two impedances and meeting a specified loaded quality factor Q₀. Algebraic design formulae are analytically demonstrated, which prove extremely simple. Explicit expressions of network frequency responses and harmonic rejection in terms of the loaded Q... View full abstract»

A simple and precise method is given for calculating the input and output impedances of a feedback amplifier, directly from its loop gain. A useful approximation to the precise result is that the input or output impedance is equal to the source or load impedance for which loop gain would equal unity View full abstract»

General methods for the synthesis of complex band-pass and band-stop analogue filters are developed for implementation by active-RC, gm-C, switched-capacitor (SC) and switched-current (SI) techniques. These principles are extended to synthesis procedures for log-domain complex realisations. Circuits for filters and group delay equalisers are presented for both ladder and cascade-biquad realisation... View full abstract»

Optical, electrical and structural properties of metal oxide thin films of tellurium dioxide (TeO₂), indium oxide (In₂O₃) and silicon monoxide (SiO) and their mixtures were studied in terms of gamma radiation influence. These films were prepared using the thermal vacuum evaporation technique. ⁶⁰Co and ¹³⁷Cs sources were used to expose the samp... View full abstract»

Equations for the 1dB compression point and third-order intermodulation point as a function of circuit and technology parameters are derived using a Volterra series expansion. The linearity analysis for both single- and double-balanced CMOS Gilbert mixers is examined. The relation between the input third-order intercept point and source inductance is studied in depth. The gate to drain overlap cap... View full abstract»

Interest in organic and polymer thin film transistors (OTFTs and PTFTs; hereafter both are called PTFTs) has grown rapidly in the last decade. However, the theory of charge transport in PTFTs lags experiments, so it is difficult to provide the required feedback to device designers and technologists. Therefore, the authors present an analysis of charge transport in PTFTs. It is based on extensive p... View full abstract»

A new physically-based compact device model of the PiN diode is presented. A one-dimensional model for the drift zone (low doped n-base region) is presented which accurately describes conductivity modulation and non-quasistatic charge storage effects within the structure. To validate the power diode compact model, simulation results are compared with those from a detailed drift-diffusion finite-el... View full abstract»

Timing jitter is a concern in high frequency oscillators; the presence of timing jitter will degrade system performance in many high speed applications. In the first part of the paper, the authors have simulated the timing jitter due to CMOS device noise in a nine-stage CMOS differential ring oscillator, and a methodology to efficiently simulate timing jitter has been developed. Simulation results... View full abstract»

The steady-state analysis and performance characteristics of the LCC-type series resonant convertor (SRC) are presented. The analysis is based on the PWM control scheme for both continuous and discontinuous conduction mode of operations. By using the same control techniques, it is shown that the control characteristics of the LLC-type SRC are substantially improved over those of the conventional S... View full abstract»

The authors present a new fully differential current-mode third-order Butterworth very high frequency G_m-C filter using current-mode linear transformation (CMLT) techniques. The systematic design method and procedure are developed to realise CMLT G_m-C filters efficiently. A third-order Butterworth lowpass filter with 200 MHz cutoff frequency, embedded bandgap reference and bi... View full abstract»

Design considerations are presented for a-Si:H based AMOLED display backplanes, including 2-TFT voltage-programmed and 4-TFT threshold-voltage-shift-resistant current-programmed circuits. The RC equivalent models of voltage-programmed and current-programmed pixels are derived, based on which array simulations are performed. Array size scalability and optimal driving requirements for a-Si:H AMOLED ... View full abstract»

An analytical method is proposed to discuss class E RF power amplifiers with finite choke inductors. All parameters in these amplifiers can be expressed in terms of circuit-component values and amplifier specifications. The component values of class E amplifiers required to achieve optimum amplification can be directly obtained after the amplifier specifications are fixed. An obvious relationship ... View full abstract»

An improved version of a recently proposed PIN diode circuit model is proposed. The most appealing feature of this model is the easy parameter extraction procedure, that requires neither an in-depth knowledge of device manufacturing, nor particularly complex measurements of device characteristics. The parameter extraction procedure developed in the paper is carried out in an automatic fashion, wit... View full abstract»

New analogue squaring, square-rooting and vector summation circuits using current conveyors (CCIIs) are presented. They consist of MOS transistors biased in the triode region, a buffered unity-gain inverting amplifier, resistors and CCIIs. A general n-input vector summation circuit is also proposed. The proposed squaring, square-rooting circuits and a two-input vector summation circuit have been i... View full abstract»

The neuron MOS transistor is a recently discovered device which is capable of executing a weighted sum calculation of multiple input signals and threshold operation based on the result of summation, thereby simulating the function of biological neurons. A comprehensive set of neuron test transistors has been designed, where a number of input gates are coupled capacitively to a floating gate, which... View full abstract»

A novel accurate CMOS current sensing circuit for the protection of smart power MOS switches, using the current mode approach is proposed. It has the advantage of not requiring any passive components and it is based on a CMOS current mode building block presenting a wide frequency bandwidth as well as temperature insensitivity. Two current sensing cells are necessary to detect open load, short-cir... View full abstract»

The established trench field stop technology 'IGBT3' is transferred to 600 V devices and supplements the 1200 V and 1700 V family. Besides an adjustment of cell geometry and pitch for the optimum compromise between on-state loss and short-circuit current, the ability to process ultrathin wafers with a thickness of 70 μm is the most demanding requirement for this device. One of the most importan... View full abstract»

Spin-dependent phenomena in semiconductors may lead to devices with new or enhanced functionality, such as polarised solid-state light sources (spin light-emitting diodes), novel microprocessors and sensitive biological and chemical sensors. The realisation of robust semiconductor spin-device technology requires the ability to control the injection, transport and detection of polarised carriers, a... View full abstract»

Pipelined cellular array implementations of arithmetic circuits are usually adopted to obtain high throughput at reasonable cost. The circuit design style used to implement the array greatly influences both performance and cost. The designer has to move in a varied and complex scenario, since nowadays scores of logic styles are known among CMOS families. Static logic styles are easy to use and the... View full abstract»

An interfacing circuit for piezoresistive pressure sensors based on a generalised current mode building block, termed operational floating amplifier (OFA), is presented. Main advantages of the proposed circuit are the very simple configuration using two OFAs and only one piezoresistor, and the highly linear frequency output, which is directly proportional to relative piezoresistance variation. Exp... View full abstract»

The authors present a new biquad filter model based on nullators, norators, current mirrors and passive R (resistor) and C (capacitor) elements. Two implementations derived from the new biquad filter model by using second generation current-controlled conveyors (CCCIIs) and operational transconductance amplifiers (OTAs) are also proposed. The two biquad implementations are capable of achieving fiv... View full abstract»