Dr. R. David Middlebrook will present a seminar on his General Feedback Theorem (GFT) at the 2004 APEC Conference, February 22, 2004. The session is entitled, “Design-Oriented Feedback Analysis—A Final Solution.” He will also be part of the Intusoft booth at the exposition tradeshow, February 23 to 25, demonstrating his GFT application on popular analog circuit topologies.
The 3-hr tutorial is a culmination of design-oriented analysis approaches presented from five previous APEC Seminars. Feedback systems are usually designed with the familiar single-loop block diagram in mind. Various non-idealities, such as unavoidable minor loops and direct forward transmission, make the single-loop block diagram progressively less useful, especially at higher frequencies. The GFT defines a "natural" block diagram model that is identical in format to the single-loop model that is conventionally assumed, thus providing a desirable link between general feedback theory and a detailed circuit diagram analyzed in terms of factored pole-zero transfer functions.
The GFT is computer friendly, and emphasis is on the numerical and graphical results obtained by use of Intusoft’s ICAP/4 SPICE circuit simulation offerings. The GFT is advantageous for designs such as integrated circuits, switch-mode power supply and feedback circuitry where the analysis of loop characteristics is required, but without breaking the loop, consequently having to reestablish the design’s operating point.