Paper Info
Title
Adaptive Frequency Compensation For Maximum And Constant Bandwidth Feedback Amplifiers
Abstract
We present an adaptive frequency compensation technique providing maximum bandwidth closed-loop amplifiers. The approach exploits an auxiliary variable gain amplifier to implement an electrically tunable compensation capacitor proportional to the feedback factor. In this manner, the closed-loop bandwidth is kept ideally constant irrespective of the closed-loop gain. The proposed method can be applied to any amplifier adopting dominant-pole compensation. As an example, we designed a CMOS amplifier providing 66-dB direct current gain and 310-MHz gain-bandwidth product. For closed-loop gains ranging from 1 to 10, the closed-loop bandwidth was found never lower than 401MHz (noinverting configuration) and 229MHz (inverting configuration). A similar amplifier with equal gain-bandwidth product, but adopting the traditional fixed compensation approach, would exhibit a closed-loop bandwidth reduced to 33MHz (noninverting) and 30MHz (inverting) when the gain magnitude is set to 10. The enhanced frequency performance is obtained with a 48% increase in current consumption, whereas the other main operational amplifier performance parameters remain almost unchanged compared with the standard solution. Copyright (c) 2011 John Wiley & Sons, Ltd.
Year
DOI
Venue
2013
10.1002/cta.824
INTERNATIONAL JOURNAL OF CIRCUIT THEORY AND APPLICATIONS
Keywords
Field
DocType
operational amplifiers, frequency compensation, constant bandwidth, feedback amplifiers, VGA, CMOS integrated circuits
Current-feedback operational amplifier,Open-loop gain,Fully differential amplifier,Control theory,Operational transconductance amplifier,Direct-coupled amplifier,Gain–bandwidth product,Electronic engineering,Power bandwidth,Mathematics,Operational amplifier
Journal
Volume
Issue
ISSN
41
4
0098-9886
Citations 
PageRank 
References 
2
0.42
8
Authors
3
Name
Order
Citations
PageRank
Salvatore Pennisi143771.32
giuseppe scotti230839.14
A. Trifiletti343363.29