A stacked DCFL structure applied to a prescalar IC and investigatedfor ASICs

摘要

The stacked DCFL (direct coupled FET logic) structure makes itpossible to have supply voltage compatibility to Si LSIs with IC circuitcurrent reduction. The idea is to stack DCFL circuits by utilizing theSchottky FET characteristic, which makes the total DCFL circuit currenthold constantly independent of any logic conditions. This circuitstructure was applied to the divide by 64/65 or 128/129 prescalar IC,which operates at 2.5 GHz on a supply voltage of 3 V with circuitcurrent of 9.8 mA. Virtual ground stability was investigated to applythe stacked DCFL to application-specific integrated circuits (ASICs).The stability of the virtual ground was confirmed by modeling thestacked DCFL circuit and simulating the circuit using SPICE