A 1.5-V FULL-SWING BICMOS LOGIC-CIRCUIT

A BiCMOS logic circuit applicable to sub-2-V digital circuits has been developed for the first time. A transiently saturated full-swing BiCMOS (TS-FS-BiCMOS) logic circuit operates twice as fast as CMOS at 1.5-V supply. A newly developed transient-saturation technique, with which bipolar transistors saturate only during switching periods, is the key to sub-2-V operation because a high-speed full-swing operation is achieved to remove the voltage loss due to the base-emitter turn-on voltage. Furthermore, both small load dependence and small fan-in dependence of gate delay time are also attained with this technique. A two-input gate fabricated with 0.3-mum BiCMOS technology verifies the performance advantage of TS-FS-BiCMOS over other BiCMOS circuits and CMOS at sub-2-V supply.