ANALYSIS AND DESIGN OF A MULTIPLE OTA-BASED OTA-C ACTIVE LOW-PASS FILTER

Abstract

-C filters have the advantage of tuning the floating inductor resulting in enhancement of gain and increase in cut-off frequency with increase in bias current. Different cases of tuning trans conductance gm1, gm1, gm. , and gm2  by changing the bias currents of multiple OTA ‘s  are studied and results are discussed. The only one method of setting of gm1 gm1 greater than gmgm2   is an innovative in changing the cut off frequency as we have flexible tuning Tran’s conductances of gm1, gm1, and gm.  And gm2. Results are consistent and are encouraging in respect of tuning of Trans conductance with bias current under the condition of gm1 gm1 greater than gmgm2.  However an OTA-C active filter other than the studied criteria has the limitations in designing of filters