0
Why is the substrate in nmos connected to ground and in pmos to vdd?
Wiki User
∙ 12y ago
we try to reverse bias not the channel and substrate but we try to maintain the source,drain junctions reversed biased with respect to the substrate so that we dont loose our current in the substrate.
Wiki User
∙ 12y ago
Anonymous
To revers bias the sunstrate
Add your answer:
Earn +20 pts
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 :)
What are sleep transistors?
A rest transistor is either a pMOS or nMOS high VT transistor and is utilized as a change to close off force supplies to parts of a configuration in standby mode. The pMOS rest transistor is utilized to switch VDD supply and henceforth is known as a "header switch."
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.
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 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.
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 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 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 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 Disadvantages of cmos over pmos and nmos?
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.
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.
