Current feedback and voltage feedback. The choice amplifiers: which one to use, when and why

Abstract

Monolithic current feedback amplifiers have been on the market now for a decade. When they were first introduced, they offered unequalled bandwidths for the price. Since that time design techniques that take advantage of the new complementary bipolar processes have allowed conventional or voltage feedback designs to bring comparable speeds, power and price to the marketplace. The purpose of this paper is to give a brief overview of the current feedback and voltage feedback topologies, and in light of this to then compare the performance of high speed amplifiers in their speed as well as the secondary areas of noise and distortion. Given this basis, guidelines are given to the design engineer which will allow him or her to select the topology best suited for a particular application.