Equivalent circuit

About: Equivalent circuit is a research topic. Over the lifetime, 34990 publications have been published within this topic receiving 473794 citations.

Retiming synchronous circuitry

Abstract: This paper describes a circuit transformation calledretiming in which registers are added at some points in a circuit and removed from others in such a way that the functional behavior of the circuit as a whole is preserved. We show that retiming can be used to transform a given synchronous circuit into a more efficient circuit under a variety of different cost criteria. We model a circuit as a graph in which the vertex setV is a collection of combinational logic elements and the edge setE is the set of interconnections, each of which may pass through zero or more registers. We give anO(?VźE?lg?V?) algorithm for determining an equivalent retimed circuit with the smallest possible clock period. We show that the problem of determining an equivalent retimed circuit with minimum state (total number of registers) is polynomial-time solvable. This result yields a polynomial-time optimal solution to the problem of pipelining combinational circuitry with minimum register cost. We also give a chacterization of optimal retiming based on an efficiently solvable mixed-integer linear-programming problem.

Flat-Band Potential of a Semiconductor: Using the Mott Schottky Equation.

Abstract: Semiconductors are an important category of materials involved in many applications in modern society. One such application revolves around the search for efficient sustainable forms of energy, in this case the use of semiconductors to assist in the conversion of light to electrical energy. Related to a semiconductor's behavior in such an application is its flat-band potential. In this article we have described an experiment suitable for fourth-year undergraduate or graduate students that involves determination of the flat-band potential of a semiconductor using electrochemical impedance spectroscopy (EIS) and the Mott–Schottky equation, which relates semiconductor–electrolyte interfacial capacitance to voltage. To demonstrate this approach we used a polycrystalline ZnO electrode in an electrolyte of 7 x 10-4 M K3[Fe(CN)6] (1 M KCl). EIS, with a suitable equivalent circuit, was used to extract interfacial capacitance data (C), which was then compared with the electrode voltage via the Mott–Schottky equati...

Electrosurgical generator power control circuit and method

Abstract: A constant power control circuit for an electrosurgical generator and a method for maintaining the electrical power output of an electrosurgical generator at a generally constant value throughout a given tissue impedance range are disclosed. The constant power control circuit and the method recognize and use the unique and simple linear characteristics associated with certain electrosurgical generator designs to monitor and control the electrical power output without having to calculate or monitor the actual output power. The constant power control circuit includes a current sampling circuit, a linear conversion circuit, and a feedback correction circuit. The constant power control circuit may also include protection circuitry that prevents the electrosurgical generator from being over-driven during high and/or low impedance loading, and reduces the severity of exit sparking by providing a quick response to high impedance indications while nonetheless maintaining increased power levels throughout a preset, nominal impedance range. The constant power control circuit and method may be included as an integral part of the overall electrosurgical generator's circuitry, or may be embodied as a separate unit that connects to, and controls, an electrosurgical generator. The constant power control circuit and method may be embodied through a variety of analog and/or digital circuit components or arrangements, including software running on computational and memory circuitry.