Q4CMOS Design
Question
Q.4. What are the various sources of power dissipation in CMOS circuits?
Answer
The various sources of power dissipation in CMOS circuits are dynamic (switching) power, short-circuit power, and static (leakage) power.
CMOS circuits dissipate power through three principal mechanisms: dynamic (switching) power, P=CV^2f, arising from charging and discharging load capacitances during logic transitions; short-circuit power, arising from a brief direct current path between VDD and ground when both the PMOS and NMOS transistors conduct simultaneously during the finite-time input transition; and static (leakage) power, arising from subthreshold leakage current through nominally-off transistors and reverse-biased junction leakage current, which persists even when the circuit is not switching.