CAD tool for amplifier design on negative-feedback nullor based ampliers
Traditional circuit design has as starting point a similar already proved design that could accomplish the desired specs. Once the circuit is selected, modifications are performed within it in order to provide the required performance. Unfortunately, this way to perform circuit design has several dr...
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| Tipo de documento: | tese |
| Estado: | Versión aceptada para publicación |
| Data de publicação: | 2007 |
| País: | México |
| Recursos: | Instituto Nacional de Astrofísica, Óptica y Electrónica |
| Repositório: | Repositorio Institucional del INAOE |
| Idioma: | inglês |
| OAI Identifier: | oai:inaoe.repositorioinstitucional.mx:1009/582 |
| Acesso em linha: | http://inaoe.repositorioinstitucional.mx/jspui/handle/1009/582 |
| Access Level: | Acceso aberto |
| Palavra-chave: | info:eu-repo/classification/Ingenieria asistida por computadora/Computer aided engineering info:eu-repo/classification/Amplificadores/Amplifiers info:eu-repo/classification/Circuitos analógicos/Analogue circuits info:eu-repo/classification/cti/1 info:eu-repo/classification/cti/22 info:eu-repo/classification/cti/2203 info:eu-repo/classification/cti/330703 |
| Resumo: | Traditional circuit design has as starting point a similar already proved design that could accomplish the desired specs. Once the circuit is selected, modifications are performed within it in order to provide the required performance. Unfortunately, this way to perform circuit design has several drawbacks, among them there are two such as: • The time needed to perform the adaptation of the circuit is too high. • Given the case that there is no circuit that could be adapted, it is necessary to invest valuable time and resources to create a new one. This thesis presents the design and development of an automated tool aimed at the design of negative feedback amplifiers based on the Structured Circuit Design theory. The main idea of this methodology is to establish an ideal solution first and from this starting point, perform the required modifications to find the particular solution of the problem. The base element of this methodology is the nullor, which is an ideal two-port element with these important characteristics: • The voltage and current at the input port always are zero. • At the output port, the voltage and current values will always accomplish the load requirements. This methodology allows to create amplifiers with one or two feedback loops and the topologies that can be implemented are: voltage amplifier, transconductance amplifier, transimpedance amplifier and current amplifier. To reach the implementation of the amplifier is necessary, at first instance, to perform the nullor synthesis. The synthesis is performed by means of active devices since they are the only ones capable to emulate the nullor characteristics. Nevertheless, the active devices have some limitations like: noise generation, limited operational frequency or a narrow bias range. The active devices in this work have been modelled using their small signal models, this way is possible to depict any active device using just capacitors, resistors and controlled sources. Using the small signal models are valid through the design process because the main goal is to obtain a Butterworth like output, accomplish certain noise level and the output signal are kept within certain voltage or current level. Therefore, the main focus of this work lies in the AC domain while the DC bias values will be taken into account just in certain design aspects. |
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