Design considerations for high-speed amplifiers using complementary BJTs
Over the past decade there has been a continual increase in the high frequency/high-speed potential of operational amplifiers, and these improvements in performance have been made possible, in part, by the development of new fast complementary BJT process technologies. The availability of fast vertical PNP transistors as well as NPNs has breathed new life into the performance of conventional voltage op-amps. In addition, the development of complementary BJT technology has also led to the emergence of a range of operational amplifiers which make use of current feedback rather than conventional voltage feedback. The concept of “current-feedback” is not a new idea, and can in fact be traced back to the early days of cathode feedback. However the circuit design symmetry required to implement these high-speed architectures has meant that the technique has only really become practical for fully-integrated implementation with true complementary BJT processing.
Design considerations for high-speed amplifiers using complementary BJTs, Page 1 of 2
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