Q7CMOS Design
Question
Q.7. Write the characteristics of CMOS logic families.
Answer
CMOS logic families are characterized by very low static power dissipation, full rail-to-rail output voltage swing, high noise margins, and a naturally complementary pull-up/pull-down transistor network structure.
The characteristics of CMOS logic families include: very low static (quiescent) power dissipation, since in steady state exactly one of the complementary PMOS/NMOS networks is off, blocking any DC current path from supply to ground; full rail-to-rail output voltage swing (output logic levels reach very close to VDD and ground); high noise margins, providing good immunity to noise/interference; a naturally complementary (dual) pull-up PMOS network and pull-down NMOS network structure for any static logic gate; and a nearly ideal, high input impedance (since inputs connect only to MOSFET gates, drawing negligible DC input current), together making CMOS the dominant technology for modern digital VLSI design.