On single amplifier bi-quadratic topologies in transimpedance configuration

Three recently proposed Active RC transimpedance topologies using single operational amplifier have been studied in detail for obtaining optimum design choices of component values. The gain sensitivity product (GSP) extensively studied in literature for the performance evaluation of active RC filters has been employed in this study to facilitate optimization of the active and passive network sensitivities of these three topologies. Modifications are suggested for classical two-opamp-based Twin-T based negative feedback type filter to reduce the number of opamps from two to one while realizing desired transimpedance as well as filtering functions. The Nodal voltage simulation technique that has been proposed to derive new Active RC filters needing opamps with grounded non-inverting inputs, from Active RC filter circuits using opamps with ungrounded non-inverting input. In this paper, this technique is used to derive a new transimpedance type filter from the low-pass filter described by Friend. All the circuits considered have been compared regarding passive and active sensitivities as well as GSP.