Applying 'Current Feedback' to Voltage Amplifiers
Derek F. Bowers · Institution of Engineering and Technology eBooks · 1993
The term “current feedback” when applied to voltage amplifiers is a source of considerable confusion and misunderstanding. When applied to operational amplifiers, the term is commonly used to describe a method of feedback relying on an inherently low impedance inverting input. When applied to instrumentation amplifiers, the term has been utilised (by the author, unfortunately) to denote a differential feedback system relying upon the use of a linearised voltage to current converter as the feedback element. Furthermore, the basic techniques described in reference have their origins in instrumentation amplifier design. The term “active feedback” has also been carelessly applied, and has frequently been perpetuated in the description of any feedback system using other than passive elements in a feedback loop. However, the term “active feedback” seems to have been initially used to describe the use of a voltage to current converter as an overall feedback element. The author has to admit that the latter usage is a useful and (potentially) non-ambiguous description for such a type of feedback, and from here on the term “current feedback” will be applied only in the foremost context.