High Speed Tunnel Diode Transistor Micrologic Circuits

摘要

A set of logically flexible digital building blocks capable of implementing various logic functions with delays of less than one nanosecond was developed and fabricated in microcircuit form. The set consists of two basic types of circuit modules; with these, all conceivable digital system logic functions can be implemented. Tunnel junction diodes and silicon transistors provide gating functions, and a universal amplifier circuit module reshapes signal waveforms, restores amplitudes, and stores signals (flip-flop operations). Subnanosecond switching time is achieved by the effective utilization of a tunnel diode transistor circuit and hybrid integration techniques for microcircuit fabrication. The circuit provides the following characteristics: (1) low power delay time product (efficient switching); (2) effective noise immunity; (3) well-defined temperature invariant transfer characteristics; (4) relaxed component tolerances as compared to other tunnel diode logic circuits; (5) high fan-in and fan-out ratios; and (6) capability of performing all logical functions with two basic circuit configurations. The circuits were developed primarily for a high-speed digital system operated at a 100- to 200Mcps clock rate with a low impedance transmission line signal distribution scheme. Analysis of the circuit, optimization of the circuit characteristics, fabrication techniques of the circuit modules, and experimental results in a high-speed digital system are discussed. (Author)