High speed, high precision operational amplifier

摘要

A DC-coupled multistage operational amplifier, the participation of the multiple stages of which, in defining the effective gain of the amplifier, is frequency dependent, such that high frequency signals are amplified by a single high speed stage and coupled directly to an output port. Low frequency signals, on the other hand, are coupled through both the high speed stage and a low frequency precision stage connected in cascade with the high speed stage. The gains of the respective high speed and low frequency precision amplifier stages are such that amplification of a high frequency input signal applied to an input port is effectively defined by the gain of the high speed first amplifier stage, so that an amplified high ferquency output signal derived from an output port is effectively derived directly from the output of the high speed amplifier stage. On the other hand, amplification of a low frequency input signal applied to the input port is effectively defined by the total gain of a cascaded signal coupling path through each of the high speed and low frequency precision amplifier stages.