A new floating controlled resistance operating in class AB

A new implementation for a floating controlled resistance operating in class AB is introduced. This uses a new translinear mixed loop of eight bipolar transistors. The circuit has been biased with DC current in such a way that it works effectively in class AB. A new building block, the third-generation controlled current conveyor (CCCIII) is then implemented. This has been obtained simply by adding a supplementary output terminal Z to duplicate the current flowing through the controlled resistance above. Simulation results, using the nominal parameters of the ALA200 bipolar arrays from ATT, demonstrate the high possibilities of the circuit. With ±1.5 V supply voltage, the power consumption of this wideband conveyor (-3 dB bandwidths greater than 30 MHz) is less than 7 mW as soon as the controlled resistance becomes lower than 250 Ω. An application example, consisting of a sinusoidal controlled oscillator, implemented from a transimpedance operational amplifier, is finally given to illustrate the versatility of the circuit