New canonic active rc sinusoidal oscillator circuits using second-generation current conveyors with application as a wide-frequency digitally controlled sinusoid generator

Abstract

This paper reports two new circuit topologies using second-generation current conveyors (CCIIs) for realizing variable frequency sinusoidal oscillators with minimum passive components. The proposed topologies in this paper provide new realizations of resistance-controlled and capacitor-controlled variable frequency oscillators (VFOs) using only four passive components. The first topology employs three CCIIs, while the second topology employs two CCIIs. The second topology provides an advantageous feature of frequency tuning through two grounded elements. Application of the proposed circuits as a wide-frequency range digitally controlled sinusoid generator is exhibited wherein the digital frequency control has been enabled by replacing both the capacitors by two identical variable binary capacitor banks tunable by means of the same binary code. SPICE simulations of the CMOS implementation of the oscillators using 0.35m TSMC CMOS technology parameters and bipolar implementation of the oscillators using process parameters for NR200N-2X (NPN) and PR200N-2X (PNP) of bipolar arrays ALA400-CBIC-R have validated their workability. One of the oscillators (with CMOS implementation) is exemplified as a digitally controlled sinusoid generator with frequency generation from 25kHz to 6.36MHz, achieved by switching capacitors and with power consumption of 7mW in the entire operating frequency range. Copyright © 2011 Abhirup Lahiri.