Lossless grounded capacitance multipliers using two CFOAs and a grounded capacitor

Two new lossless grounded capacitance multipliers (GCMs) are proposed, in which a grounded capacitor and two current-feedback operational amplifiers (CFOAs) are used. Nevertheless, two floating resistors are used in the proposed GCMs. The proposed GCMs consist of three passive components. Thus, the proposed GCMs are obtained with a minimal quantity of passive components. The proposed GCMs have a high operating frequency range at a high multiplying factor. Identical passive component requirements are not needed in the proposed GCMs. In addition, the proposed GCMs can be controlled electronically by using the current-controlled current conveyor with a buffer instead of the second CFOA. However, there is no investigation on electronic tunability in this study. 0.18 μm CMOS technology parameters are employed for the CFOAs used in the proposed lossless GCMs. The layout area of the CFOA is 978.75 μm². All simulations are performed with the SPICE program. In all simulations, supply voltages of the CFOA are selected as ±1.25 V. The simulation results verified the theoretical results from about 30 Hz to 3 MHz. The simulation results show that temperature changes do not affect the proposed GCMs much. The proposed circuits consume 1.91 mW power. In addition, the GCMs in this paper are used in the first-order active low-pass filter, and experiments of these circuits are achieved with AD844s, which are commercial devices for the CFOAs. Also, the experimental results confirm the theoretical results from about 2.5 kHz to 1 MHz.