SPICE Analysis Research Articles

A spice‐based approach to steady state circuit analysis

AbstractA new SPICE‐based approach for steady state circuit analysis is presented which uses SPICE computational capabilities and a master programme to carry out the periodic response. the master programme implements a suitable method for steady state analysis and is linked with SPICE only via I/O SPICE files. This allows the use of all SPICE analyses together with the new one simply by adding a new statement in the input SPICE file. In this paper the bases of this technique, including the chosen steady state method and the whole system structure, are discussed. Simulation results produced by this technique have been compared, by means of two meaningful examples, with those obtained both by SPICE and by a dedicated simulator for steady state analysis working in the frequency domain.

A CCD frequency prescaler for broadband applications

A broadband, compact, and power-efficient frequency prescaler based on two-phase CCDs (CCD-FP) is described. It is similar in operation to flip-flop-based divide-by-N circuits. However, the maximum operating frequency is determined by the charge transit time between CCD electrodes, rather than the propagation delay of a logic gate in which circuit parasitics limit performance, so that relatively large gate length CCD electrodes (1 mu m) can be used in a millimeter-wave device. A prototype CCD-FP has been implemented in a GaAs-AlGaAs modulation-doped CCD (MD-CCD) technology and demonstrated at frequencies up to 18 GHz. The CCD-FP has a constant input voltage sensitivity as a function of input frequency and the output signal is phase locked to the input. Expansion of the prescaler modulus incurs no penalty in speed of operation and very modest increases in power dissipation, circuit complexity, and chip area. In conjunction with PISCES two-dimensional transient simulations of the 1- mu m MD-CCD, SPICE analysis predicts that an InGaAs-based CCD-FP is capable of operating frequencies approaching 100 GHz. >

Trace Element Analysis of Food Spices by Inaa

Abstract Extensive use of food spices in oriental and Latin American cooking, pharmacy, and perfumery entails the evaluation of trace element contents in them. Instrumental neutron activation analysis (INAA) was used to determine the concentration of 18 trace elements (essential, toxic and non-essential) in six different spices consumed in Rawalpindi/Islamabad area. Turmeric powder and ginger powder were found to contain relatively high amounts of essential elements and low amounts of toxic elements. The comparison of our values with Canadian and Egyptian data shows variation in trace element contents of red pepper, turmeric, coriander and ginger. The estimated dietary intake through food spices show that these may be considered appreciable sources of trace element intake due to their extensive use. With the present studies the investigation of trace element contents of 13 food spices has been completed.

Simplified calculation of wave-coupling between lines in high-speed integrated circuits

The construction of time-domain solutions by the superposition of modes is explained for the general case, which may not have any symmetry in the lines or terminations. This simplified method requires that the logic-gate terminal impedances be approximated by linear effective resistances that can be adequately determined by SPICE analysis of the actual logic gates. Several examples of results of crosstalk calculations made by the simplified method are presented and compared with corresponding results obtained using the SPICE transmission-line methods of Tripathi and Rettig (IEEE Trans. Microwave Theory Tech., vol. MTT-33, no.12, p.1513-18, 1985) along with full SPICE models of the logic gates. The simplified approach is shown to give satisfactory agreement for most purposes. >

Model for CMOS/SOI single-event vulnerability

A lumped-parameter model derived from transistor characterization data has been used in SPICE analyses to study and predict the single-event-upset thresholds for SIMOX SOI (separation by implantation of oxygen, silicon-on-insulator) SRAMs (static random-access memories) with a variety of cell designs. The modeling of CMOS/SOI transistors with fully bottomed sources and drains includes direct representation of the parasitic lateral bipolar structure. Results indicate that, in the SOI devices investigated, single events simulate a localized bipolar response, even in devices with bodies electrically tied to active nodes. The bipolar response enhances the destabilizing effect of an ion event. The total current impulse contributing to upset can be significantly greater than that produced by direct ionization within the hit transistor, i.e., devices can be upset by ions that deposit less than the total charge required to initiate logic state reversal. In light of this, advanced CMOS/SOI-SOS logic with short channel lengths (and therefore significant parasitic bipolar gain) may exhibit critical LETs (linear energy transfers) lower than expected from simple scaling rules, and thinning of the active regions may not significantly reduce single-event rates in such CMOS/SOI digital circuits. >

Spectrophotometric analysis of irradiated spices

Seven different spices (thyme, cinnamon, coriander, caraway, pimento, paprika, black pepper) were treated by gamma radiation at an absorbed dose of 10 kGy, and the effect on chemical quality was determined. The effects of this dose were assessed by spectrophotometric analysis of some water-soluble constituents of spices (carbohydrates; carbonyl compounds) and on the content of water-insoluble steam-volatile oils. The colour of paprika and the content of piperine in pepper held in different packaging materials were measured in unirradiated and irradiated samples as a function of storage time. In all cases irradiation does not bring about any distinct qualitative or quantitative chemical changes based on spectrophotometric analysis of spice extracts.

A modified time-domain model for nonlinear analysis of an operational amplifier

A generalized two-pole time-domain model useful for op amp analysis in both linear and nonlinear regions is presented. It models slew enhancement and degradation effects for different types of input devices and voltage steps. This has been accomplished by taking a more limited two-pole model and modifying it to take into account the initial conditions in both the nonlinear and linear regions and the slope at the beginning of either the slewing or linearly settling time periods. Both the slewing period and settling period are accurately predicted by the model. A comparison of this model with SPICE analyses on a typical CMOS op amp circuit gives excellent agreement.

Multielement analysis of food spices by instrumental neutron activation analysis

Twenty-four elements in six food spices were estimated by non-destructive instrumental neutron activation analysis. The problems in determining Cu were discussed.

Neutron activation analysis and autoradiographic purity examination of semiconductor grade silicon wafers : M. Jaskolska, L. Walis and L. Rowinska. Electron Technol.8, (3/4), 109 (1975)

A compact add-on model is proposed to simulate the mechanism of charge trapping and release (detrapping) and its effect on the threshold voltage of MOSFET devices. The model uses implicit algebraic differential equations compatible with transient analysis in SPICE. It also shares the accuracy level of the transient analysis. A micro-model approach is used, and each trap is treated by a two-state Markov process. The normalization of trap behavior can be enabled or disabled, so that the designer can compare average trap behavior to the result of repeated Monte-Carlo simulations of a circuit. In this manner, the model can compromise between device-level modeling and circuit-level modeling. Unlike models geared towards digital circuit design, the trapping and release rates need not be constant during electrical stress. The trapping and release rates are a function of time, as they depend on the circuit state-space equations. An operational amplifier is analyzed using the new model, and the proposed approach is compared with the state of the art.

High transmission X-ray masks for lithographic applications : A. Bassous, R. Feder, E. Spiller and J. Topalian. Solid-St. Technol. p. 55 (September 1976)

A compact add-on model is proposed to simulate the mechanism of charge trapping and release (detrapping) and its effect on the threshold voltage of MOSFET devices. The model uses implicit algebraic differential equations compatible with transient analysis in SPICE. It also shares the accuracy level of the transient analysis. A micro-model approach is used, and each trap is treated by a two-state Markov process. The normalization of trap behavior can be enabled or disabled, so that the designer can compare average trap behavior to the result of repeated Monte-Carlo simulations of a circuit. In this manner, the model can compromise between device-level modeling and circuit-level modeling. Unlike models geared towards digital circuit design, the trapping and release rates need not be constant during electrical stress. The trapping and release rates are a function of time, as they depend on the circuit state-space equations. An operational amplifier is analyzed using the new model, and the proposed approach is compared with the state of the art.

The Analysis of Spices and Herbs for Aflatoxins

The Analysis of Spices and Herbs for Aflatoxins

Annual and monthly rainfall trend in plantation and spice farming Western Ghats districts

Rainfall analysis of important plantation and spices producing districts such as The Nilgiris (Tamil Nadu), Kodagu (Karnataka) Idukki (Kerala) and Wayanad (Kerala) with 100 years data (1901 to 2000) obtained from the India Meteorological Department (IMD), Pune indicated that mean annual rainfall were 1839.7mm, 2715.7mm, 2979.4mm and 3381.0mm with a coefficient of variation (CV) of 16.0%, 17.0%, 25.8% and 19.6%, respectively. The contribution of southwest monsoon(June-September) to the annual rainfall in these districts were 80.3% (Wayanad), 78.9% (Kodagu), 65.2% (Idukki) and 56.3% (The Nilgiris) with corresponding CV of 24.1%, 20.6%, 32.5%, and 24.6%, respectively. The declining trend in mean annual rainfall was noticed for Idukki, Wayanad and The Nilgiris, whereas, for Kodagu, it was stable. The change was significant in Wayanad and The Nilgiris. Similar trend was also observed for the southwest monsoon rainfall. The maximum decline in annual and southwest monsoon rainfall was noticed in The Nilgiris followed by Wayanad. Pre and post monsoon rainfall receipts were comparatively less with high inter-annual variations. The pre-monsoon (March-May) receipt and its coefficient of variation (CV) was 252.4mm & 20.6% (Kodagu), 360.9mm & 36.5% (Idukki), 251.7mm & 36.6% (The Nilgiris) and 274.2mm & 54.2% (Wayanad). The post monsoon (October-December) rain was maximum in Idukki 548.1mm (CV 27.9%) followed by The Nilgiris 503.4mm(CV 31.3%), Wayanad, 333.1mm(CV 37.8%) and Kodagu 310.5mm (CV 32.7%). In all these districts there was a declining trend in the pre-monsoon rain with maximum decline in The Nilgiris. Similar declining trend was also observed in post-monsoon rain except for The Nilgiris, where the trend has been increasing. Overall, the study gives an indication that there was a spatial and temporal variation in rainfall amounts. The maximum decline in annual rainfall and the southwest monsoon was observed in The Nilgiris and Wayanad. July was the rainiest month in all the districts studied. Significant negative trend was asscoaited with The Nilgiris for January, May, June, July and August months. Whereas, in Kodagu, no significant trend was observed for mean monthly rainfall, except for August. In Idukki, significant negative changes were noticed for January, March, October and December rainfall. Monthly rainfall of January, March, April and July monthly rainfall were showed significant negative trend in Wayanad,. These negative trends across important plantation and spices producing districts of the Western Ghats would affect not only the agricultural economy of this sector but also water resources.

Solid Sampling Device for Direct Gas Chromatographic Analysis of Spices

Abstract In developing gas chromatographic methods for spice analysis, a solid sampling device was used to eliminate the tedious and time-consuming preparation of samples by steam distillation. The device can be used only with the ionization detector. Analyses compare favorably with those on steam-distilled samples.

Spice Analysis, Spectrophotometric Method for Determining Piperine in Oleoresins of Black Pepper

Spice Analysis, Spectrophotometric Method for Determining Piperine in Oleoresins of Black Pepper

Analysis of Spices

Analysis of Spices

Percentage of an Extractive as a Means of Identification and Analysis of Drugs and Spices

Percentage of an Extractive as a Means of Identification and Analysis of Drugs and Spices