New mathematical formulation for designing a fully differential self-biased folded cascode amplifier
Abstract
One of the most important building blocks in analog circuit design is the operational amplifiers. This is because of their versatility and wide spread usage in many applications such as communications transmitters and receivers, analog to digital converters, or any other application that requires a small signal to be amplified. The basic amplifier topologies are introduced. Then, some operational amplifiers topologies are introduced with some techniques to self bias these amplifiers. The folded cascode fully differential Op-Amp with self bias is presented. This is one of the newest amplifier topologies which provide stable self-biased amplifiers. A new mathematical model for fully differential folded cascode amplifiers is presented and generalized to include the family of fully differential complementary amplifiers. This formulation focuses on deriving detailed design equations for the amplifier gain and frequency response. The equations are verified through time domain and frequency domain simulations of different fabrication processes to ensure the validity of the model across a wide range of processes. The model was verified against TMSC 180nm, 250nm, and 350nm fabrication processes. The new model agrees well with simulations; with 1% error for the amplifier gain and <7% error for amplifier bandwidth. The relatively high error value for the bandwidth is because the model considers the worst case scenario and overestimates the output capacitance. Finally, the algorithm of getting this formulation is extended to include special and commonly used cases. This formulation proved to be very useful in designing stable, self-biased, fully differential folded cascode amplifiers.
Department
Electronics & Communications Engineering Department
Degree Name
MS in Electronics & Communication Engineering
Graduation Date
2-1-2012
Submission Date
May 2012
First Advisor
Darwish, Ali
Second Advisor
Abdelmoneum, Mohamed
Extent
NA
Document Type
Master's Thesis
Library of Congress Subject Heading 1
Operatiol amplifiers -- Design and construction.
Library of Congress Subject Heading 2
Metal oxide semiconductors, Complementary.
Rights
The author retains all rights with regard to copyright. The author certifies that written permission from the owner(s) of third-party copyrighted matter included in the thesis, dissertation, paper, or record of study has been obtained. The author further certifies that IRB approval has been obtained for this thesis, or that IRB approval is not necessary for this thesis. Insofar as this thesis, dissertation, paper, or record of study is an educational record as defined in the Family Educational Rights and Privacy Act (FERPA) (20 USC 1232g), the author has granted consent to disclosure of it to anyone who requests a copy.
Institutional Review Board (IRB) Approval
Not necessary for this item
Recommended Citation
APA Citation
Abdelsalam, M.
(2012).New mathematical formulation for designing a fully differential self-biased folded cascode amplifier [Master's Thesis, the American University in Cairo]. AUC Knowledge Fountain.
https://fount.aucegypt.edu/etds/1233
MLA Citation
Abdelsalam, Mohamed Adel. New mathematical formulation for designing a fully differential self-biased folded cascode amplifier. 2012. American University in Cairo, Master's Thesis. AUC Knowledge Fountain.
https://fount.aucegypt.edu/etds/1233