Abstract: An integrated circuit comprises plural superconducting circuit blocks connected through superconducting wiring strips, and each superconducting circuit block includes at least one superconducting logic circuit, constant input/output circuits connected between the input/output nodes of the circuit block and the superconducting logic circuit; parameters of the constant input/output circuits are regulated such that statically flow-in/flow-out current is approximately equal to zero at the input/output nodes of the superconducting logic circuit, whereby the superconducting logic circuit operates at the optimum operating point after the integration.

Abstract: The level of bias current (12) required by a superconductor integrated circuit (2 & 4) is lowered by separating the circuit into portions having separate ground planes and supplying the bias current to the circuit portion (2) in one ground plane in series (10) with that for the circuit portion (4) in another ground plane. To maintain DC isolation between those circuit portions, SFQ pulses inputted (SFQ IN) move across the separate ground planes through a pair of inductively coupled SQUIDS (3 & 5) that define a DC transformer; and a combiner (7) reconstitutes and outputs the SFQ pulses. To provide inductive coupling the DC transformer includes a primary (25) and isolated secondary (5) winding.

Abstract: A superconducting circuit device of a voltage-type logic device is large in current driving capability and, accordingly, electric power consumption; however, the switching speed is not so fast, and a superconducting circuit device of a fluxoid-type logic device is small in current driving capability and, accordingly, the electric power consumption; however the switching speed is faster than that of the superconducting circuit device of the voltage-type logic device, wherein the superconducting circuit device of the voltage-type logic device and the superconducting circuit device of the fluxoid-type logic device are selectively used in a superconducting circuit such as a superconducting random access memory, a superconducting NOR circuit and a superconducting signal converting circuit so as to realize small electric power consumption and high-speed switching action.