Application, modeling and characterization of operational amplifiers#
Operational Amplifiers: types and modeling techniques#
Types of operational amplifiers
The operational amplifier was invented as a controller for analog computers. The "standard" operational amplifier has a floating (differential) voltage input and a grounded voltage output. Nowadays, different types of operational amplifiers exists.
Presentation
The presentation "OpAmps: types" briefly summarizes the historical development of operational amplifiers and lists the properties of the different types.
Presentation in parts
Video
Study
Chapter 8.1
Modeling of operational amplifiers
Manufacturers of operational amplifiers usually provide macro-models for SPICE simulation. Such models, however, do not provide design information.
Presentation
The presentation "Operational Amplifiers: modeling" presents techniques for modeling of specific behavioral apsects, for both SPICE simulators and for SLiCAP.
Presentation in parts
Operational Amplifiers: modeling (parts)
Videos
Study
Chapter 8.3
Operational Amplifiers: negative feedback amplifiers with OpAmps as controller#
Feedback amplifiers with standard operational amplifiers as controllers
Operational amplifiers are intended to be used as controllers in negative feedback amplifiers. Standard operational (voltage) amplifiers use both supply terminals as return path of the output port. This complicates the implementation of output current sensing.
Presentation
The presentation "Feedback configurations with operational amplifiers" illustrates this and presents alternative current sensing techniques.
Presentation in parts
Feedback configurations with operational amplifiers (parts)
Video
Feedback amplifier configurations with operational amplifiers (6:37)
Study
Chapter 8.4.1
Synthesis of multiple-controller feedback configurations
If a feedback amplifier comprises multiple controllers, alternative configurations that all have the same ideal gain can be found by pairing the nullators and norators differently.
Presentation
The presentation "Multiple-nullor circuit synthesis" demonstrates this technique for an active-feedback inverting voltage amplifier.
Presentation in parts
Multiple-nullor circuit synthesis (parts)
Video
EE3C11 lecture 9: Multiple nullor Circuit Synthesis
Study
Chapter 7.6.1