Načrtovanje malošumnega operacijskega ojačevalnika v tehnologiji CMOS

MANEVSKA, MARIJA (author), Trontelj, Janez (mentor)

V diplomskem delu sem analizirala optimizacijo glede na šum operacijskih ojačevalnikov, izvedenih v tehnologiji CMOS in njihovo tipično aplikacijo. Iz simulacij sem ugotovila, da so operacijski ojačevalniki z n-vhodno stopnjo, ki so izvedeni v procesu TSMC 0.35um, najbolj ustrezni za malošumne aplikacije. Analizirala in primerjala sem tri topologije operacijskih ojačevalnikov: transimpedančni operacijski ojačevalnik, operacijski ojačevalnik s prepognjeno kaskodo in operacijski ojačevalnik z izboljšano prepognjeno kaskodo. Ugotovila sem, da ima operacijski ojačevalnik z izboljšano prepognjeno kaskodo najboljše šumne lastnosti. Izvedeni nizkošumni operacijski ojačevalnik ima zelo nizek šumni spekter pri sobni temperaturi, in sicer v_in = 12,84 nV/sqrt{Hz} pri f = 100Hz in v_in = 4,99 nV/sqrt{Hz} pri f = 1kHz. V tipični aplikaciji operacijskega ojačevalnika razmerje med signalom in šumom na vhodu znaša SNR_in = 37,7; razmerje med signalom in šumom na izhodu znaša SNR_out = 38,08.

• Language: Slovenian
• Keywords: operacijski ojačevalnik CMOS, optimizacija glede na šum.
• Work type: Undergraduate thesis
• Organization: FE - Faculty of Electrical Engineering
• Year: 2014
• PID: 20.500.12556/RUL-29982
• Publication date in RUL: 23.10.2014

Secondary language

• Language: English
• Title: Low Noise CMOS Operational Amplifier Design

Abstract

This thesis addresses the analysis of noise optimisation possibilities for op amps in CMOS technology and its further use in low-noise applications. The conclusion obtained on the basis of computer simulations is that operational amplifiers with nmos input differential pairs, produced in the TSMC 0.35um process are the most suitable for low-noise applications. Therefore, three op amp topologies with nmos input differential pairs were analysed and later compared: transimpedance op amp, folded cascode op amp and improved folded cascode op amp. The results of computer simulations have lead to the conclusion that the improved folded cascode op amp has the best noise properties. At room temperature the low-noise op amp's input noise spectre is v_in = 12.84 nV/sqrt{Hz} at f = 100 Hz and v_in = 4.99 nV/sqrt{Hz} at f = 1 kHz. The signal-to-noise ratio in the op amp's typical application is SNR_in = 37.7 at the input and SNR_out = 38.08 at the output of the amplifier.

• Keywords: CMOS op amp, noise optimisation.