
149Different Types of Logic Gates
6.8.6 Unconnected Input(s) not Permitted
Due to very high gate-source impedance, a small static charge built up can drive a gate
voltage higher than the drain. Therefore, the unconnected inputs are not permitted in
MOSFET based gates.
6.9 CMOS
6.9.1 Importance and Features of CMOS Logic Circuits
CMOS is most important logic circuit due to the following.
(i) An enhancement mode p-channel acts as pull up and n-channel enhancement mode
MOSFET act as a logic driver (pull down) When n-channel is ON, the p-channel is
OFF and when n-channel is OFF, the p-channel is ON. It means the D.C. (steady
state) current dissipation ...