Small-signal model: Difference between revisions

Revision as of 04:20, 13 April 2005

Revision as of 08:27, 13 April 2005

Line 1:

'''Small signal modelling''' is an analysis method used in [[electrical engineering]], to describe [[nonlinear devicesdevice]]s in terms of [[linear devicesdevice]]s.

==Motivation==

Electronic circuits generally involve small time-varying signals carried over a constant [[bias]]. This suggests using an method akin to approximation by [[differentials]] to analyze relatively small perturbations about the [[bias point]]. Any nonlinear device which can be described quantitatively using a formula can then be linearized about a bias point by taking taking partial derivatives of the formula with respect to all governing variables. These partial derivatives can be associated with physical quantities (such as [[capacitance]], [[resistance]] and [[inductance]]), and a circuit diagram relating them can be formulated.

Electronic circuits generally involve small time-varying signals carried over a constant [[bias]]. This suggests using an method akin to approximation by [[differentials]] to analyze relatively small perturbations about the [[bias point]].

Electronic circuits generally involve small time-varying signals carried over a constant [[bias]]. This suggests using an method akin to approximation by [[differentials]] to analyze relatively small perturbations about the [[bias point]]. Any nonlinear device which can be described quantitatively using a formula can then be linearized about a bias point by taking taking partial derivatives of the formula with respect to all governing variables. These partial derivatives can be associated with physical quantities (such as [[capacitance]], [[resistance]] and [[inductance]]), and a circuit diagram relating them can be formulated.

Small signal models exist for [[diodes]], [[field effect transistors]] and [[bipolar transistors]].

[[Category:Electrical engineering]]

{{stub}}