ota

As the gain in an OT A can be controlled by the current from an external source (the bias current lABd, possibilities are opened up for new applications which have up to now been difficult to perform satisfactorily with discrete components. A simple application of the OT A, for example, is amplitude modulation. Although it is basically possible to effect this with one or more discrete transistors, closer inspection shows that discrete circuits do not achieve all forms of amplitude modulation really satisfactorily.