REALIZATION OF SIGNAL GENERATING CIRCUITS USING OPERATIONAL TRANS RESISTANCE AMPLIFIER

Abstract

As signal processing extends to higher frequencies, the traditional design methods based on voltage operational amplifiers are no longer adequate. A traditional operational amplifier has a bandwidth which is dependent on the closed- loop voltage gain. To overcome this problem, circuits operating in current mode are preferred. The current feedback op-amp has become now commercially available. The circuits using these devices employ current processing techniques to improve dynamic speed capability & it provides a constant bandwidth virtually independent of gain. Both the input & output terminals are characterized by low impedance, therefore eliminating response limitations incurred by capacitive time constants. This device is called an Operational Transresistance Amplifier (OTRA). Thus using the operational transresistance amplifier as the active building block various signal generating circuits can be realized with more flexibility in controlling the frequency of waveforms. The Ope...