CURRENT DIFFERENCING TRANSCONDUCTANCE AMPLIFIERS (CDTAs) AND THEIR APPLICATIONS IN SIGNAL PROCESSING

Abstract

ABSTRACT The basic important building blocks which are frequently employed in Analog Signal Processing are Amplifiers, Oscillator and Filters. In the present work an active building block Current Differencing Transconductance Amplifier, especially suitable for analog signal processing is presented. CDTA is a current mode element whose input and output signals are currents where output current of CDTA can be electronically adjusted. In this dissertation various other active devices which are useful in analog signal processing are briefly described. PSPICE simulation results of CDTA using the parameters of 0.5µm MIETEC CMOS technology and transistor model parameters of PR100 N(PNP) and NR100 N(NPN) of the bipolar arrays ALA400 from AT&T are included to verify the expected values. Various signal processing applications of CDTA namely, amplification, integration, differentiation have been presented. Current-mode, Voltage-mode and mixed-mode filter circuits using CDTA as the active building block have been included in the dissertation. Applications of CDTAs in realization of harmonic oscillators have also been presented. Finally a resonator based universal filter using CDTA has been presented.