Design exibility and power consumption in addition to the cost, have
always been the most important issues in design of integrated circuits
(ICs), and are the main concerns of this research, as well. Energy
Consumptions: Power dissipation (P ) and energy consumption are - diss
pecially importantwhen there is a limited amountof power budgetor
limited source of energy. Very common examples are portable systems
where the battery life time depends on system power consumption. Many
different techniques have been - veloped to reduce or manage the circuit
power consumption in this type of systems. Ultra-low power (ULP)
applications are another examples where power dissipation is the primary
design issue. In such applications, the power budget is so restricted
that very special circuit and system level design techniquesare needed
to satisfy the requirements. Circuits employed in applications such as
wireless sensor networks (WSN), wearable battery powered systems [1],
and implantable circuits for biol- ical applications need to consume
very low amount of power such that the entire system can survive for a
very long time without the need for changingor recharging
battery[2-4]. Using newpowersupplytechniquessuchas
energyharvesting[5]and printable batteries [6], is another reason
for reducing power dissipation. Devel- ing special design techniques for
implementing low power circuits [7-9], as well as dynamic power
management (DPM) schemes [10] are the two main approaches to control
the system power consumption. Design Flexibility: Design exibility is
the other important issue in modern in- grated systems.
