VDIBA-Based Fractional-Order Oscillator Design

Abstract

This paper deals with a voltage-mode integer- and fractional-order oscillator design providing compact and simple CMOS structure. The proposed circuit consists of only one grounded/floating capacitor, one grounded/floating resistor, and one high-performance and versatile active element so-called voltage differencing inverting buffered amplifier (VDIBA), employing only six transistors. Compared with the corresponding already introduced fractional-order oscillators, it offers the benefit of low transistor count. In addition, it offers the well-known advantages of fractional-order oscillators about the capability for achieving very low and high oscillation frequencies with reasonable component values. The design parameters of the proposed oscillator can be electronically adjusted via change of order of the fractional-order capacitor and/or by means of bias current of the internal transconductance of the VDIBA. Theoretical results are verified by SPICE simulations using TSMC 0.18 m level-7 LO EPI SCN018 CMOS process parameters with ±0.9 V supply voltages.