True RC integrators based on current conveyors with tunable time constants using active control and modified loop technique

Three active integrator schemes with tunable time constants are presented. The second generation current conveyors (CCIIs) are used as active devices to achieve better frequency responses than that of operational amplifiers. The first scheme uses a capacitance multiplication technique for time constant control; the second uses an enhanced negative resistor to increase the time constant; and the last employs a modified loop technique to tune the time constant. All three schemes have been implemented in the laboratory using commercially available current conveyors (AD844s). The experimental results agree with theoretical prediction very well.>