Monolithic nullor-a universal active network element

The design of a monolithic integrated nullor is described. It is a universal active element with floating input and output ports and with large internal gain. The element consists of a differential input stage, a symmetrical level shift stage, and a differential output stage. In the latter stage the collectors of a long-tailed transistor pair function as a pair of connected vessels for the output currents at high common-mode output impedance. This gives the output port its floating character. The element is capable of conveying a potential from one input terminal to the other input terminal and a current from one input terminal to the other output terminal at an accurate unity gain. The total inaccuracy of these operations is in the order of 2/spl times/10/SUP 4/ at signal voltage levels of 1 V and 1 mA. The element has a bandwidth of 25 MHz and can handle maximum signal values of 10 V and 1 mA. The availability of such universal active elements makes it possible to minimize the number of active elements and passive precision elements in implementation of analog system functions.