Model Broad Agency Announcement (BAA)Ferdowsi University of Mashhad, Iran proposed principles of optimal design of operational amplifiers (op-amps) by applying nanotransistors.
Hamidreza R. Dehsorkh has worked in this field of science, managing to figure out some optimal conditions for designing nanotransistor-based novel op-amps.
"Operational amplifiers are popular devices widely used in analogue electronics. In most cases, a precise model of its settling behavior is needed to optimize an op-amp," he said in an interview with the news service of Iran Nanotechnology Initiative Council (INIC).
"Since folded cascode circuit is commonly used in amplifier applications, our calculations are based on it. For a step input, current relations in op-amp junctions were derived and velocity-saturation model for MOS transistors was applied," Dehsorkh emphasized.
He solved the set of differential equations and obtained a relation for nonlinear settling of the nano-scale amplifier (assuming that the amplifier is bipolar and oscillation damping exists in case of linear settling). Finally, by applying boundary conditions and their consistency, a general relation for settling was postulated.
"In addition to the analysis of the settling behavior, we managed to present a correlation for settling (including both linear and nonlinear) of the mentioned op-amps," the Iranian researcher added
"Optimizing analogue to digital converters with respect to their power consumption is highly valuable particularly in telecommunication industries. It would lengthen battery life and reduce costs and device volume and weight", Dehsorkh mentioned.
Details of this research work are available at the IEEE Transactions On Circuits and Systems II: Express Briefs, volume 56, pages 348 to 388, 2009.