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How does the CMOS circuit function as an inverter?
You can easily see that the CMOS circuit functions as an inverter by noting that when VIN is five volts, VOUT is zero, and vice versa. Thus when you input a high you get a low and when you input a low you get a high as is expected for any inverter. You might be wondering what happens in the middle, transition area of the curve.
Where does Region IV of the nMOS inverter occur?
Region IV occurs between an input voltage slightly higher than VM but lower than VDD-VTP. Now the NMOS device is conducting in the linear region, dropping a low voltage across VDS. Since VDS is relatively low, the PMOS device must pick up the tab and drop the rest of the voltage (VDD-VDS) across its VSD junction.
Why is there no current through the NMOS device?
Since the NMOS device is on vacation, there is no current flow through either device. VDD is available at the Vo terminal since no current is going through the PMOS device and thus no voltage is being dropped across it. The PMOS device is forward biased (VSG > -VTP) and therefore on.
How is complementary MOSFET ( CMOS ) technology used today?
Complementary MOSFET (CMOS) technology is widely used today to form circuits in numerous and varied applications. Today’s computers CPUs and cell phones make use of CMOS due to several key advantages.
What does low-impedance mean in the CMOS?
For the CMOS inverter the text states “once the transients have settled, a path always exists between VDD and the output realizing a high output (“one”), or, alternatively, between VSS and output for a low output (“zero”). This is equivalent to stating that the output node is always a low-impedance node in steady state.”
Which is an important characteristic of a CMOS circuit?
An important characteristic of a CMOS circuit is the duality that exists between its PMOS transistors and NMOS transistors. A CMOS circuit is created to allow a path always to exist from the output to either the power source or ground.
What does complementary metal oxide semiconductor ( CMOS ) stand for?
Complementary metal–oxide–semiconductor ( CMOS ), also known as complementary-Ali metal–oxide–semiconductor ( COS-MOS ), is a type of MOSFET (metal–oxide–semiconductor field-effect transistor) fabrication process that uses complementary and symmetrical pairs of p-type and n-type MOSFETs for logic functions.