Solving differential equations in analog domain

• Autor(a) principal: Silva, Duarte Gonçalves Lopes da
• Data de Publicação: 2023
• Tipo de documento: Dissertação
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/10362/162021
• topic: Analog computing; Differential equation solver; CMOS; Folded-Cascode; Integrator; Domínio/Área Científica::Engenharia e Tecnologia::Engenharia Eletrotécnica, Eletrónica e Informática

A growth in the use of analog computers has been seen in the last few years despite of the dominance of digital computers, this is due to the fact that it was noticed that analog computers could solve differential equations not only faster but also in a more efficient way, which means drawing less power. This lead to the interest in studying how a computer can solve this type of equations and what it takes to do so. With this in mind a circuit that describes a variation of the law of exponential decay is proposed, this implicated the design of an folded cascode operational amplifier, which was implemented using 130nm MOS technology. This then led to the study of this amplifier in an integrator configuration as well as the proposed circuit, which in a later stage was made configurable by adding a logic controller to control the resistors that establish the coefficients of the equation. With the obtained results it was possible to validate the objective specifications for the amplifier as well as observe that the circuit was able to come to successful results within the known constraints of the components used for this circuit. This circuit was able to reach solutions much faster than a digital computer facing the same problem, 30s versus 0.3s, while consuming considerably less power, 40mW versus 72W.