Power-Delay Trade-Offs in Complementary Metal-Oxide Semiconductor Circuits Using Self and Optimum Bulk Control

Power dissipation and delay are the challenging issues in the design of VLSI circuits. This manuscript explores joint effect of Self-Bias transistors (SBTs) and Optimum Bulk Bias Technique (OBBT) on CMOS circuits. Earlier investigations on SBTs shows decrease in power dissipation of combinational as well as sequential circuits. We extend the analysis by studying the effect of OBBT on the static and dynamic power of CMOS circuits with SBTs coupled amid the pull-up/down network and the supply bars. Extensive SPICE simulations have been carried out in 0.18 μm technology. Results demonstrate that, a 73% drop in power in case of combinational circuits and 43% in case of sequential circuits can be accomplished by engaging OBBT in digital circuits. Trade-off between power and delay is also been presented.