Negative Feedback, Amplifiers, Governors, and More [Historical]

Class-D Audio Amplifiers with Negative Feedback

There are many different designs for audio amplifiers. Class-D, or switching, amplifiers generate their output signal in the form of a high-frequency square wave of variable duty cycle (ratio of on time to off time). The square-wave nature of the output allows a particularly efficient output stage, with minimal losses. The output is ultimately filtered to remove components of the spectrum above...

Negative Feedback Semiconductor Optical Amplifiers and All-Optical Triode

The field of optical communications is moving toward the realization of photonic networks with wavelength division multiplexing (WDM) utilizing the full bandwidth of optical fibers. Conventionally, an erbium-doped fiber amplifier (EDFA) and a semiconductor optical amplifier (SOA) are used for amplifying an optical signal in optical communications. SOAs can contribute to this and offer the key a...

MIMO Series-Series Feedback Amplifiers

This brief defines a new type of multiple-input multiple-output (MIMO) amplifier. We present basic structures for this MIMO series–series feedback amplifier (MIMO-SSFA), and the basic design equations. We provide a detailed example showing how this MIMO-SSFA may be used as a transmitting circuit for multiconductor interconnections.

AN-597 Current Feedback Amplifiers

MAPK Cascades as Feedback Amplifiers

Interconvertible enzyme cascades, exemplified by the mitogen activated protein kinase (MAPK) cascade, are a frequent mechanism in signal transduction pathways. There has been much speculation as to the role of these pathways, and how their structure is related to their function. A common conclusion is that the cascades serve to amplify biochemical signals so that a single bound ligand molecule ...