Exercise 1.9 Although the dynamic power is the primary source of power dissipation in CMOS, leakage current produces a static power dissipation V × Ileak. The smaller the on-chip dimensions, the more signifi cant is the static power. Assume the fi gures shown in the following table for static and dynamic power dissipation for several generations of processors.

Technology Dynamic power (W) Static power (W) Voltage (V)

a. 250 nm 49 1 3.3

b. 90 nm 75 45 1.1 1.9.1 [5] <1.5> Find the percentage of the total dissipated power comprised by static power.

1.9.2 [5] <1.5> If the static power depends on the leakage current, Pst = V × Ileak, fi nd the leakage current for each technology.

1.9.3 [5] <1.5> Determine the ratio of static power to dynamic power for each technology.

Consider now the dynamic power dissipation of different versions of a given processor for three different voltages giv en in the following table.

1.2 V 1.0 V 0.8 V

a. 80 W 70 W 40 W

b. 65 W 55 W 30 W 1.9.4 [5] <1.5> Determine the static power for each version at 0.8 V, assuming a static to dynamic power ratio of 0.6.
1.9.5 [5] <1.5> Find the leakage current for each version at 0.8 V.
1.9.6 [10] <1.5> Determine the larger of the two leakage currents at 1.0 V and 1.2 V, assuming a static to dynamic power ratio of 1.7.