An Active-only Grounded Capacitance Simulator

The article proposes an active-only electronically controllable capacitance simulator. This proposed circuit comprises a current operational amplifier (COA) cooperating with a current controlled current conveyor trans-conductance amplifier (CCCCTA), without any passive component. The principal feature of the proposed circuit is that the obtained capacitance can be electronically adjusted via input bias current. Consequently, it can easily be adapted in automatic control or micro controller/microprocessor-based systems. In addition, it is very suitable to further develop in integrated circuit architecture. The simulation results obtained from PSpice found that the proposed circuit offers a tunable capacitance range of 3.5pF–4.5pF with operating frequency range of lkHz-2MHz. The power consumption is 13.4mW at ±2.5V power supplies. An example application in a current-mode filter is included.