Emitter-couple logic circuit design based on the threshold-arithmetic algebraic system

Based on the threshold-arithmetic algebraic system which has been proposed for current-mode circuit design, we propose a systematic methodology for emitter-couple logic (ECL) circuit design. Compared to the traditional methodologies and the theory of differential current switches, the proposed methodology uses the HE map and the characteristics of the internal current signals of ECL circuits to determine the external voltage signals. The operations of the HE map are direct and simple, and the current signals are easy to add or subtract, which make this methodology more flexible, direct, and effective, and make it possible to design arbitrary binary and multi-valued logic functions. Two example circuits are designed and simulated by HSPICE using 0.18 μm TSMC technology. Simulation results confirm the validity of the proposed methodology.