Describe CMOS inverter.

Ans:

CMOS inverter that is also called Complementary MOSFET Inverters, are several of the most broadly used and adaptable MOSFET inverters utilized in chip design. They operate along with very little power loss and at relatively high speed. Moreover, the CMOS inverter has fine logic buffer characteristics, in which, its noise margins in both high and low states are huge. A CMOS inverter consists of a PMOS and a NMOS transistor connected associated at the drain and gate terminals, a supply voltage VDD on the PMOS source terminal, and a ground linked at the NMOS source terminal, were VIN is associated to the gate terminals and VOUT is associated to the drain terminals. Consider diagram given below.

This is significant to notice that the CMOS does not include any resistors, that makes this more power efficient that a usual resistor-MOSFET inverter. Since the voltage at the input of the CMOS device varies in between 0 and 5 volts, the state of the PMOS and NMOS varies consequently. If we model all transistors as a simple switch activated through VIN, the inverter's operations can be seen very simply:

Diagram of CMOS inverter