A General Class of Current-Mode Circuit Transfer Functions Using OTA-C Integrator Loop Structures

摘要

This paper introduces a general class of current-mode circuit transfer functions using OTA-C integrator loop structures based on cascade realizations. It is shown that basic first-order and second-order structures are constructed with Operational Transconductance Amplifiers (OTA) and the grounded capacitors, and that high-order circuit transfer functions can be realized employing the two basic structures. The circuit can realize various circuit transfer functions by suitable connections of the first-order and the second-order structures. And the circuit characteristics can also be tuned through adjusting the bias currents of the OTAs. Furthermore, the effect of non-idealities on the circuit characteristics is also discussed by using a model of the transconductance gain. Some examples are given together with simulated results by PSPICE.