answersLogoWhite

0


Best Answer

CMOS and NMOS are two logic families. As the name itself indicates, CMOS is complementary Metal Oxide Semiconductor technology. It uses both PMOS and NMOS transistors for design. Whereas, NMOS logic family uses only NMOS FETs for design.

User Avatar

Wiki User

10y ago
This answer is:
User Avatar
More answers
User Avatar

Wiki User

10y ago

CMOS is Complementary Metal Oxide Semiconductor technology. It is widely used logic family for implementing digital logic. CMOS uses both PMOS and NMOS transistors within it. The advantage is speed but the disadvantage is power consumption.

This answer is:
User Avatar

User Avatar

Wiki User

10y ago

BiCMOS retains the advantages of CMOS like zero static current and high input impedance but it increse the output current, which will speed up the CMOS.

This answer is:
User Avatar

Add your answer:

Earn +20 pts
Q: What are the Disadvantages of cmos over pmos and nmos?
Write your answer...
Submit
Still have questions?
magnify glass
imp
Related questions

Is cmos a combination of both nmos and pmos?

yes


What happens if you interchange pmos and nmos in a cmos inverter?

it becomes a buffer


What are advantages of transmission gate logic over Cmos logic?

cmos logic circuit uses particularly pmos or nmos viz. passes strong 1 and strong zero respectively and also degraded zero's and one's in their respective cases of p and nmos so to remove deggraded output the nmos and pmos are combined together for strong output level


What are the differences between nmos and pmos transistors?

NMOS is built with n-type source and drain and a p-type substrate, while PMOS is built with p-type source and drain and a n-type substrate. In a NMOS, carriers are electrons, while in a PMOS, carriers are holes. When a high voltage is applied to the gate, NMOS will conduct, while PMOS will not. Furthermore, when a low voltage is applied in the gate, NMOS will not conduct and PMOS will conduct. NMOS are considered to be faster than PMOS, since the carriers in NMOS, which are electrons, travel twice as fast as holes, which are the carriers in PMOS. But PMOS devices are more immune to noise than NMOS devices. Furthermore, NMOS ICs would be smaller than PMOS ICs (that give the same functionality), since the NMOS can provide one-half of the impedance provided by a PMOS (which has the same geometry and operating conditions).


What happens if you change pmos to nmos and nmos to pmos in cmos?

It will act like a buffer but not the exact buffer. Since nmos conduct logic 1 weakly and pmos conduct logic 0 weakly, the output ranges from vdd-vtn to vtp. For eg. If you apply 5v then the op will be 4.3 not the complete 5v. If you apply 0v then output will be 0.7v not 0 v. Hope this works


What is the use of pseudo nMOS gates in digital design?

These circuits use nMOS for implementation of a whole gate + one pMOS which is connected between positive supply and nMOS.


What type of doping have the drain and the source of a PMOS transistor?

PMOS - (drain + source) = p-type doping NMOS - (drain + source) = n-type doping :)


Which mos needs logic '1' on its gate terminal to get ON?

It is NMOS FET. PMOS works in a reverse way.


What is difference between inverter and buffer?

if you connect Nmos and Pmos other way around then it act as buffer


Why the resistance of PMOS is greater than NMOS?

because pmos has low mobility . the inverter threshold voltage can be shifted to the middle and the inverter is more symmetrical in terms of transistor times.


What are the advantages of PMOS and NMOS?

* reduce the complexity of the circuit* low static power consumption* high noise immunity* high density of logic function on a chipThe most important advantage of CMOS is the very low static power consumption in compare with NMOS technology. On the other hand, CMOS technology is more complex to fabricate then NMOS technology, so it is more expensive. However, almost every todays digital circuits are CMOS. You want to use NMOS only when you want to fabricate fast and low-cost a simple circuit. The most important advantage of CMOS is the very low static power consumption in compare with NMOS technology. On the other hand, CMOS technology is more complex to fabricate then NMOS technology, so it is more expensive. However, almost every todays digital circuits are CMOS. You want to use NMOS only when you want to fabricate fast and low-cost a simple circuit.


Why Pmos transistor is usually larger than Nmos transistor in layout?

Due to differences in carrier mobility between P and N type semiconductor, for similarly doped channels the channel of a PMOS FET will be a bit wider than the channel of an NMOS FET so that they both have identical channel resistance. To make the channel wider the PMOS FET will take a larger chip area.