Showing papers on "NQS published in 2002"

An MOS transistor model for RF IC design valid in all regions of operation

Abstract: This paper presents an overview of MOS transistor modeling for RF integrated circuit design. It starts with the description of a physical equivalent circuit that can easily be implemented as a SPICE subcircuit. The MOS transistor is divided into an intrinsic part, representing mainly the active part of the device, and an extrinsic part responsible for most of the parasitic elements. A complete charge-based model of the intrinsic part is presented. The main advantage of this new charge-based model is to provide a simple and coherent description of the DC, AC, nonquasi-static (NQS), and noise behavior of the intrinsic MOS that is valid in all regions of operation. It is based on the forward and reverse charges q/sub f/ and q/sub r/ defined as the mobile charge densities, evaluated at the source and at the drain. This intrinsic model also includes a new simplified NQS model that uses a bias and frequency normalization allowing one to describe the high-order frequency behavior with only two simple functions. The extrinsic model includes all the terminal access series resistances, and particularly the gate resistance, the overlap, and junction capacitances as well as a substrate network. The latter is required to account for the signal coupling occurring at RF from the drain to the source and the bulk, through the junction capacitances. The noise model is then presented, including the effect of the substrate resistances on the RF noise parameters. All the aspects of the model are validated for a 0.25-/spl mu/m CMOS process.

MOSFET modeling for low noise, RF circuit design

Abstract: In this paper, high frequency (HF) AC and noise modeling of MOSFETs for low noise, radio frequency (RF) integrated circuit (IC) design are discussed. Scalable parasitic model and the Non-Quasi-Static (NQS) model are discussed and verified with the measured data. For the noise modeling, extracted noise sources of MOSFETs in 0.18 μm CMOS process and from RF noise measurements are presented. Finally, the design consideration including selection of device size, bias condition and design of the device geometry are discussed.

The EKV 3.0 Compact MOS Transistor Model: Accounting for Deep-Submicron Aspects

Abstract: Keywords: EKV ; Device Modeling ; MOST Modeling ; RF ; NQS Note: (invited) Reference EPFL-CONF-149508 Record created on 2010-06-24, modified on 2017-06-01

The Foundations of the EKV MOS Transistor Charge-Based Model

Abstract: Keywords: EKV ; Device Modeling ; MOST Modeling ; RF ; NQS Note: (invited) Reference EPFL-CONF-149565 Record created on 2010-06-24, modified on 2017-06-01

Direct parameter extraction on RF-CMOS

Abstract: The good knowledge of all parameters of the models used with the circuit simulations is one of the major prerequisites for a successful design. This is particularly true for the design of analog radio-frequency (RF) circuits. An efficient and accurate method to directly extract the parameters needed for accurate modeling of transistors in a standard CMOS sub-micron technology for RF-applications is presented. The paper concentrates on the extraction procedure, with emphasis on its simplicity, hence excluding fitting or optimization, and on the accuracy of its results. The extracted parameters are applied to a first order nonquasistatic (NQS) model and the simulation results compared with measurements. Excellent agreement between simulations and measurements up to 50GHz is achieved.

Determining the onset frequency of nonquasistatic effects of the MOSFET in AC simulation

Abstract: The frequency dependence of nonquasistatic (NQS) operation in MOS transistors is studied. With the help of a two-dimensional device simulator, a time varying sine function is applied to the gate at different frequencies. The inversion channel charge variation in response to the input signal at high frequency is compared with that at dc. By observing the frequency that generates an observable delay in channel charge response to the applied signal, the onset frequency of the NQS effect can be determined, which gives a limit to the valid quasistatic (QS) assumption. It was found that the onset frequency of the NQS effect is very close to f/sub T/, the unity gain frequency of a transistor, and the QS approximation is sufficient for most of the practical applications.

A spectrophotometric method for the determination of prazosin hydrochloride in tablets

Abstract: Prazosin (1) 1-(4-amino-6,7-dimethoxy-2-quizanolinyl)-4-(2-furanylcarbonyl) piperazine is an antihypertensive and a potent vasodilatory agent in the quinazoline family and also has been found to be value in the treatment of heart failure. The drug and its formulations are official in the British Pharmacopeia and United States Pharmacopoeia. There are fluorimetric, UV spectrophotometric, GLC, TLC, voltametric, and differential pulse polarographic13−15 methods in the literature for the assay of the drug. The official USP XXII method uses a HPLC technique for the determination of 1 in capsules . There is no conventional method for the tablets. HPLC is widely used for the assay of the drug in body fluids16−18 and biological samples. There is only one visible-range spectrophotometric method in the literature, and so a simple, time-saving and sensitive method for the assay of prazosin hydrochloride in pharmaceuticals and bulk sample formulations is needed. This paper describes a spectrophotometric method based on the reaction of prazosin hydrochloride with 1,2-naphthoquinone-4-sulphonic acid (NQS) via its amino group on the side chain attached to the 2-position of the dihydropyridine ring. NQS was previously reported to be a sensitive colour reagent for several primary and secondary amines21−23. ∗Corresponding author

Reduced voltage swing digital differential driver

Abstract: A predriver for a differential pair having a reduce voltage swing is disclosed having fast switching speed and low power consumption. The predriver includes a p-type MOS transistor, and a first and second n-type MOS transistor. The source of the p-type MOS couples to the first power supply rail. The gate of the first n-type MOS transistor couples to the gate of the p-type MOS transistor to form an input. The drain of the first n-type MOS transistor couples to the drain of the p-type MOS transistor to form an output. The drain of the second n-type MOS transistor couples to the source of the first n-type MOS transistor. The source of the second n-type MOS transistor couples to ground. The gate of the second n-type MOS transistor couples to the output. The presence of the second n-type MOS transistor alters the voltage swing of the predriver to be from the threshold voltage level to the full power supply voltage, substantially reducing the current or power consumption.

A Spectrophotometric Method for the Determination of Prazosin Hydrochloride in Tablets

Abstract: A rapid and sensitive analytical method was developed for the spectrophotometric assay of prazosin hydrochloride. The method is based on the formation of a coloured derivative between the drug and 1,2-naphthoquinone-4- sulphonic acid sodium salt (NQS). The reaction proceeds quantitatively at pH 4.5 and 70°C for 40 min. After the extraction of the derivative with chloroform: n-butanol (3:1), the absorbance was measured at 400 nm. The method was applied to commercially available tablets and the results were statistically compared with those obtained by ultraviolet spectrophotometric and differential pulse polarographic methods using t- and F-tests.

1D physically based non-quasi-static analog behavioral BJT model for SPICE

Abstract: A compact 1D non-quasi-static BJT model (NQS BJT) based on the analog behavioral modeling capabilities of the SPICE simulator is described. The NQS BJT model parameters are derived directly from the physical device structure. A momentum relaxation time parameter is also included as equivalent inductivity, yielding more accurate prediction of unity gain frequency and phase characteristics. The efficiency of the novel NQS model is demonstrated by comparison with the standard Gummel-Poon model and experimental results.

A non-quasi-static small-signal model of the four-terminal MOSFET for radio and microwave frequencies

Abstract: An original, fully analytical non-quasi-static (NQS) small-signal model of the MOS transistor is proposed for analysis and simulation of radio and microwave frequency circuits. We report results of frequency-domain analysis, the main features and experimental verification of the novel NQS four-terminal model derived in the time-domain (Kordalski, Int. Conf. on Signals and Electron. Sys., 2000). The carrier velocity saturation effect is taken into account in this model. The model is computationally efficient, physically consistent and can be applied to an arbitrary configuration of device operation.

Simulation Study of Non-Quasi Static Behaviour of MOS Transistors

Abstract: In this paper, we study the 'non-quasi static' (NQS) behaviour of MOS transistors using an exact quasi static Look-up Table (LUT) [1] MOSFET model implemented in a general-purpose circuit simulator SEQUEL [2], device simulator ISE-TCAD [3] and SPICE BSIM3v3 [4] QS and NQS models. An NMOS transistor of channel length 2 um is simulated using LUT, ISE and SPICE3 and terminal currents are qualitatively studied. The method for extraction of terminal charges, which are required for circuit simulation using the LUT approach also presented.

A single relaxation-time non-quasi-static model for monolithic MESFET devices

Abstract: In this contribution a MESFET equivalent circuit that takes into account the device’s non-quasi-static (NQS) effects is presented. The model topology is deduced directly from the small-signal measurement analysis and consists of a small-signal equivalent circuit that can be obtained from the linearization of a non-linear NQS model with non-linear state-functions (terminal charges and currents) that include a single relaxation-time. Results confirm that just one relaxation-time for all components is needed. The proposed model provides small-signal simulation performance similar to conventional models, but incorporating NQS effects in a consistent way and using just a reduced number of non-linear functions.