OA-15 Frequent Faux Pas in Applying Wideband Current Feedback Amplifiers

As op amp operating speeds have moved to ever higher frequencies, a whole new set of design concerns have come into play for linear op amp applications. With the development of the current feedback topology, design concerns unique to that topology must also be considered if optimal performance is to be achieved from devices offering over 200 MHz −3 dB bandwidths. This discussion will review some of the considerations common to all wideband linear op amp applications as well as topics unique to the current feedback topology pioneered by Comlinear Corporation. These design guidelines are intended to help the designer get the full potential out of Comlinear’s high performance, current feedback, operational amplifiers. Since there are quite disparate areas to consider here, the approximate order of discussion will follow a perceived frequency of occurrence ranking. Those considered first seem to impact every designer, with more particular concerns dealt with later.