CMOS Current Mode Logic Gates for High-Speed Applications

This paper presents results of a design that uses CMOS current mode logic that can be used to implement the high precision, speed critical elements of the mixed-signal systems. The design is based upon the 0.25-μm CMOS TSMC process. The propagation delays of the new current mode logic are compared to those of equivalent gates implemented in conventional CMOS logic. The results show a propagation delay improvement of more than 200% using the current mode logic. The application of the proposed current mode building blocks is illustrated in a typical mixed-signal circuit, the phase detector for a high-speed phase locked loop with good speed improvement over conventional CMOS logic.