High-Speed Bipolar MUX Modeling and Design

This paper presents modeling and optimized design of Current Mode Logic (CML) MUX. Propagation delay models with few terms are presented. The most accurate model has errors lower than 2%. By using the proposed models a design optimization is proposed. In particular, the bias currents which gives the minimum propagation delay is found. Moreover, it is demonstrated that at the cost of a 10% increase in propagation delay a 40% reduction in the power dissipation can be achieved. The models and design strategies are validated using both a traditional and a high-speed bipolar process which have a transition frequency equal to 6 GHz and 20 GHz, respectively.