Design of ACP Tunnel-Diode-Coupled Circuits

The performance of the Advanced Circuit Program (ACP) circuits described by D. H. Chung and J. A. Palmieri can be improved by replacing the coupling resistor with a pair of tunnel diodes. The low impedance and power gain properties of the tunnel diode increase the fan-power and provide better control of signal levels. In addition, the improved rise times increase circuit speeds to the extent that delays of less than 1 nsec per logic function have been demonstrated. Since the tunnel diode pair can be designed to perform and, or, or majority logic functions, the logic flexibility of these circuits is greater than that of the resistor-coupled circuits. The design techniques which lead to a consistent set of logic circuits and to binary full adders are discussed. The very fast rise times generated by the tunnel diode pair require the use of transmission lines as the interconnection medium. The techniques used to minimize the effects of noise and reflections on circuit performance are discussed.