Dynamic Logic

Abstract

All digital circuits; be they memories, latches, registers, or random logic; come in two flavors: static and dynamic. Dynamic circuits are sometimes faster than their static counterparts, they might also dissipate less power. But one thing is for certain: all dynamic circuits are very compact. Dynamic CMOS combinational logic is always smaller, faster, and more power-efficient than its static counterpart. Meanwhile, it keeps the zero static current and large noise margins of CMOS. It seems like the perfect logic family, and in many cases it can be. However, all dynamic circuits suffer from severe signal integrity issues that make their design and use far from a done deal. We have to understand and deal with these issues because dynamic logic is inevitable in high-performance datapaths.