Análise e projeto de amplificador de transcondutância para aplicação em um conversor sigma-delta incremental

Abstract

This work aims to research, specify, design, implement, and test a Transconductance Amplifier (OTA) fully differential to be used in a prototype of an Incremental Sigma-Delta Converter (IADC) with characteristics aimed at achieving high resolutions with low power consumption. More specifically, the development of an IADC system/circuit focused on sensor measurements, such as temperature and biomedical signals. The stages involve researching the requirements (necessary specifications) for the OTA to operate in the IADC, transistor-level design in the Virtuoso software by Cadence Design Systems using 90nm technology, conducting dynamic and static tests, and incorporating the OTA into the implementation of the analog part of the IADC, presenting modulation results. After verifying the specifications and implementing the technology, characteristic simulations are carried out, which include: transient or time-domain tests (TRAN analysis), frequency-domain tests (AC analysis), stability tests, tests to verify offset, the common-mode input range (CMIR), output range, it’s frequency response and stability, DC gain and phase margin, settling time and slew rate, common-mode rejection ratio (CMRR), power supply rejection ratio (PSRR), and finally, corner simulations. After the testing phase, it was verified that the amplifier meets the proposed initial specifications.