文章基本信息

标题：A Two Stage Op-Amp Phase Margin Symbolic Expression
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作者：Alexandru Gabriel Gheorghe ; Mihai Eugen Marin
期刊名称：MATEC Web of Conferences
电子版ISSN：2261-236X
出版年度：2018
卷号：210
DOI：10.1051/matecconf/201821002040
语种：English
出版社：EDP Sciences
摘要：A phase margin symbolic expression of a two stage Miller compensated operational amplifier is computed in this paper. Using this expression, an analysis to evaluate the influence of the Miller and load capacitance on phase margin is performed. This way, a designer can rapidly choose the optimal set of values to fulfil an imposed phase margin. The phase margin expression is based on poles/zeros symbolic expressions obtained using a symbolic LR algorithm able to compute both the numerical values and the approximate symbolic expressions of poles and zeros of a circuit. The numerical values obtained with this algorithm are compared with those computed by SPECTRE. The example is a two stage Miller compensated operational amplifier designed in a 180nm CMOS technology.