A dichotomy exists in the design of modern microelectronic systems: they
must be simultaneously low power and high performance. This dichotomy
largely arises from the use of these systems in battery-operated portable
(wearable) platforms. Accordingly, the goal of low-power design for batterypowered
electronics is to extend the battery service life while meeting
performance requirements. Unless optimizations are applied at different
levels, the capabilities of future portable systems will be severely limited by
the weight of the batteries required for an acceptable duration of service. In
fixed, power-rich platforms, the packaging cost and power density/reliability
issues associated with high power and high performance systems also force
designers to look for ways to reduce power consumption. Thus, reducing
power dissipation is a design goal even for non-portable devices since
excessive power dissipation results in increased packaging and cooling costs
as well as potential reliability problems. Ldi/dt noise concerns have also
become an important factor that demands low-power consumption in highperformance
integrated circuits. Therefore, as power dissipation increases,
the cost of power delivery to the ever-increasing number of transistors on a
chip multiplies rapidly.