A newly developed Josephson logic gate array is described. This gate array has 576 switching devices (Josephson Interferometers) and it has attained the high speed switching time of 33ps with a 2-input OR circuit. Employing and AC-powered latch circuit, the gate array has a single power supply. The total power dissipation of the gate array chip has been estimated to be 2 mW. This gate array includes all the necessary types of function blocks to accommodate any kinds of computer logics. Shift-resistor and 4-bit full-adder circuits have been successfully operated.

A DC-powered complementary circuit employing interferometers in investigated using simulation. It is shown that an output inductor and two kinds of damping resistors are necessary to suppress circuit oscillations. Switching speed is expected to be less than 25 ps at a current density of 5000 A/cm2 for lead-alloy devices.

The prototype of a newly proposed ac-powered Josephson Programmable Logic Array (JPLA) has been fabricated and experimentally investigated. The JPLA can operate more than 10 times as fast as a semiconductor PLA and with one-thousandth of its power dissipation.